Removal of Reactive Black 5 by zero-valent iron modified with various surfactants手稿
2024版Removed
Socioeconomic Factors
Factors such as population density, economic development, and social inequality can affect the vulnerability of communities to the removed phenomenon Higher population density and economic development levels may increase exposure and susceptibility to its impacts
13
04
Response strategies and measures
2024/1/24
14
Preventive measure
要点一
Risk assessment
Identify potential risks and hazards that could lead to removed situations, and assess their likelihood and impact
要点二
Mitigation measures
Implement measures to reduce the likelihood or impact of removed events, such as improving safety procedures, enhancing security measures, and providing training and education
2024/1/24
12
Trend prediction and evaluation
PSAF-PDMDAAC复合絮凝剂的制备与性能
PSAF-PDMDAAC复合絮凝剂的制备与性能张锐;付颖寰;宋宇;王永为;于春玲;董晓丽;薛文平【摘要】以聚二甲基二烯丙基氯化铵(PDMDAAC)为有机改性剂,制备了聚二甲基二烯丙基氯化铵(PDMDAAC)-聚硅酸铝铁(PSAF)复合絮凝剂,考察了复合pH、物料配比、温度及时间等因素对PDMDAAC-PSAF絮凝性能的影响.研究发现,PDMDAAC-PSAF复合絮凝剂的最佳制备条件为:复合pH为10,m(膨润土):m(PDMDAAC)为200∶1,温度为60℃,反应时间为1h.此条件下获得的复合絮凝剂(质量分数为8％),在投加量为1.5％(絮凝剂与模拟染料废水体积比)时,对活性艳蓝染料模拟废水脱色率达87.7％.相比较PSAF絮凝剂(脱色率77.1％),PDMDAAC-PSAF复合絮凝剂显示出更好的絮凝脱色效果和应用前景.%PDMDAAC was prepared as organic modifier of PSAF. The inorganic-organic composite flocculants PSAF-PDMDAAC were prepared for wastewater treatment. PSAF-PDMDAAC composite flocculant was studied in optimum preparation conditions for the composite pH, compound ratio, composite temperature, compound time, compound dosage, and so on. The optimum preparation is that the composite pH 10, m( bentonite) :m(PDMDAAC) = 200 : 1, composite temperature is 60 ℃ , compound time is 1 h. When the dosage was 1. 5% (volume ratio of flocculant and water), removal of reactive blue dye wastewater rate was 87. 7%.【期刊名称】《大连工业大学学报》【年(卷),期】2012(031)003【总页数】4页(P195-198)【关键词】聚硅酸铝铁;聚二甲基二烯丙基氯化铵;膨润土;复合絮凝剂【作者】张锐;付颖寰;宋宇;王永为;于春玲;董晓丽;薛文平【作者单位】大连工业大学轻工与化学工程学院,辽宁大连 116034;大连工业大学轻工与化学工程学院,辽宁大连 116034;大连工业大学轻工与化学工程学院,辽宁大连 116034;大连工业大学轻工与化学工程学院,辽宁大连 116034;大连工业大学轻工与化学工程学院,辽宁大连 116034;大连工业大学轻工与化学工程学院,辽宁大连116034;大连工业大学轻工与化学工程学院,辽宁大连 116034【正文语种】中文【中图分类】X703.50 引言随着染料工业的迅速发展,印染废水已经成为我国主要有害废水之一。
ChIP常见问题汇总
ChIP常见问题汇总1．ChIP是什么答：染色质免疫沉淀技术（Chromatin Immunoprecipitation，简称ChIP）是研究体内蛋白质与DNA相互作用的一种技术。
它利用抗原抗体反应的特异性，可以真实地反映体内蛋白因子与基因组DNA结合的状况。
2．ChIP有哪些应用答：近年来由于该技术不断的发展和完善，其应用范围已经从研究目的蛋白与已知靶序列间的相互作用，发展到研究目的蛋白与整个基因组的未知序列的相互作用；从研究一个目的蛋白与DNA的相互作用，发展到研究两个蛋白与DNA共同结合的相互作用；从研究启动子区域的组蛋白的修饰，发展到研究结合在DNA序列上的蛋白复合物。
3．ChIP技术的原理答：生理状态下把细胞内的DNA与蛋白质交联在一起，通过超声或酶处理将染色质切为小片段后，利用抗原抗体的特异性识别反应，将与目的蛋白相结合的DNA片段沉淀下来。
染色质免疫沉淀技术一般包括细胞固定，染色质断裂，染色质免疫沉淀，交联反应的逆转，DNA的纯化，以及DNA的鉴定。
因为ChIP实验涉及的步骤多，结果的重复性较低，所以对ChIP实验过程的每一步都应设计相应的对照，而且对结果的分析也需要有一定的经验。
4．做ChIP试验，必须做甲醛固定么答：不一定，视样品及试验方案而定。
做甲醛固定的为X-ChIP，而不需要固定的为N-ChIP。
甲醛能有效的使蛋白质-蛋白质，蛋白质-DNA，蛋白质-RNA交联，形成生物复合体，防止细胞内组分的重新分布。
甲醛的交联反应是完全可逆的，便于在后续步骤中对DNA和蛋白质进行分析。
甲醛的交联反应可被加入的甘氨酸终止。
5．为什么必须将DNA切碎至少于1000bp大小（大约3个核小体~400-500bp）答：为确保ChIP实验有良好精度。
若您的平均片段长度大于1000bp，您将会分离获得包含您目标序列的DNA，但所要研究的蛋白会离您目标序列有700个核苷酸的距离。
6．为什么使用鲑鱼精子DNA来封闭琼脂糖珠子为什么我的样品中鲑鱼精子DNA不会发生PCR反应答：鲑鱼精子用于降低降低染色质DNA与琼脂糖珠子的非特异性结合。
电凝聚法处理印染废水
1.1 材料与仪器 材料：活性黑 5 染料，硫酸，氢氧化钠，氯化钠，硫
收稿日期：2018-09-10 作者简介：吕 芳（1979—），女，河北省保定人，讲师，硕士，研究方向为无机化工。
9期
吕 芳：电凝聚法处理印染废水
55
酸钠，硝酸钠，碳酸钠，重铬酸钾。 仪器：UV-755B 紫外可见分光光度计（上海精密
Key words: electrocoagulation; color removal; reactive black 5; removal rate
印 染 废 水 成 分 复 杂 、色 度 高 、排 量 大 ，严 重 破 坏 生态环境，已经成为最难治理的有害废水之一。近年 来，为了提高印染质量，在印染过程中加入多种难生 物 降 解 的 新 型 助 剂 ，进 一 步 增 加 了 印 染 废 水 的 处 理 难度［1］。印染废水的传统处理方式有生物降解法、物 理 吸 附 法 、氧 化 法 等 ，这 些 方 法 各 有 优 势 ，也 存 在 一 定 的 局 限 性 ，例 如 工 艺 复 杂 、能 耗 高 、易 造 成 二 次 污 染等［2-4］。电凝聚技术由于设备简单、操作简便、成本 低廉、适用面广、处理效果好，受到了广泛关注［5-6］。电 凝 聚 法 处 理 印 染 废 水 的 效 果 受 多 种 因 素 影 响 ，合 适
的 参 数 不 仅 可 以 达 到 良 好 的 处 理 效 果 ，也 能 有 效 地 减少能源浪费［7］。
本文以自制电凝聚系统处理活性黑 5 模拟印染 废 水 ，研 究 了 电 解 时 间 、电 流 密 度 、印 染 废 水 初 始 质 量 浓 度 、废 水 初 始 pH 和 电 解 质 种 类 对 印 染 废 水 色 度、CODCr 去除率的影响。
石墨烯基复合材料去除水中重金属研究进展
CHEMICAL INDUSTRY AND ENGINEERING PROGRESS 2017年第36卷第2期·602·化 工 进 展石墨烯基复合材料去除水中重金属研究进展滕洪辉，彭雪，高彬（吉林师范大学环境科学与工程学院，吉林 四平136000）摘要：近几年，石墨烯及其复合材料因其比表面积大、传输电子能力强、结构稳定、可吸附多种污染物，被认为是极具发展潜力的环保新材料，尤其是在重金属分离方面具有明显的优势。
本文综述了各类石墨烯材料在水中重金属去除方面的研究现状，对比分析了不同材料对镉、汞、铬、铜、铅、锌和砷离子的去除能力及机理。
认为石墨烯复合材料在水中分散情况、活性官能团种类、电子传输能力调控和重复使用性能对重金属离子去除有重要影响。
指出控制石墨烯片层聚集、增加亲水性、提高可回收性和制备高灵敏选择性电极将是石墨烯材料修饰改性的研究热点。
此外，石墨烯复合材料对一些有机污染物也有良好的吸附能力，制备能够吸附多类别污染物的净水剂也将成为石墨烯复合材料的一个主要研究方向。
关键词：石墨烯；复合材料；吸附中图分类号：X703 文献标志码：A 文章编号：1000–6613（2017）02–0602–09 DOI ：10.16085/j.issn.1000-6613.2017.02.028Removal of heavy metals from water by graphene compositesTENG Honghui ，PENG Xue ，GAO Bin（College of Environmental Science and Engineering ，Jilin Normal University ，Siping 136000，Jilin ，China ）Abstract ：In recent years ，graphene and its composites are considered new promising environmentalprotection materials ，because they have large specific surface area ，strong transmission electron ability and stable structure which renders them ability to adsorb more kinds of pollutants than other materials ，especially for heavy metals. The current researches of the removal of heavy metals from the water by graphene materials are reviewed in this paper. The removal ability and mechanism of cadmium ，mercury ，chromium ，copper ，lead ，zinc and arsenic ions by graphene materials are analyzed. The results show that the dispersion of graphene materials in water ，the type of reactive functional groups ，control of electronic transmission and the reuse performance of graphene composites have significant effects on the removal of heavy metal ions. We also point out that controlling graphene layers aggregation ，increasing the hydrophilicity ，improving the recycle ability and preparing high sensitive selective electrode will be hot topics of graphene materials modified researches. In addition ，graphene composites also have good adsorption capacity for some organic pollutants ，so the preparation of graphene composites as purifiers for many pollutants will become one of the main research directions of graphene composites.Key words ：graphene ；composites ；adsorption水环境中存在的大量重金属严重影响了动植物的正常生长，对生态系统和人类健康构成了极大的威胁。
搅拌条件对氢氧化镁混凝性能及絮体特性的影响
2018年第37卷第2期 CHEMICAL INDUSTRY AND ENGINEERING PROGRESS·761·化 工 进展搅拌条件对氢氧化镁混凝性能及絮体特性的影响肖淑敏1，2，赵建海1，2，魏磊1，2，池勇志1，2（1天津城建大学环境与市政工程学院，天津 300384；2天津市水质科学与技术重点实验室，天津 300384） 摘要：通过氯化镁在碱性条件下经搅拌生成氢氧化镁处理活性橙染料模拟配水，研究了搅拌条件对氢氧化镁混凝性能和絮体特性的影响。
以絮凝指数FI 与zeta 电位为考察指标，对絮体形成机理进行了探讨，并对絮体形貌进行观察，旨在揭示絮体形成过程与絮凝效果的关系。
结果表明，延长快速搅拌时间有利于絮体形成，以搅拌45s 为最佳，再延长则会导致絮体被打碎，脱色处理效果变差；慢速搅拌时间以3min 为最佳，过长也会导致絮体破碎。
在最佳搅拌时间基础上发现搅拌速度也是影响混凝性能和絮体特性的主要因素。
快搅或慢搅搅速过低，则不利于形成絮体或絮体增长；若搅速过高，形成的絮体会被打碎，这些都使得脱色处理效果变差。
实验条件下，在Mg 2+计投加量为150mg/L 时，以转速250r/min 或速度梯度G 值126.3，快速搅拌45s ，之后转速60r/min 或G 值18.5，慢速搅拌3min ，氢氧化镁混凝性能最佳，可充分发挥其吸附、电性中和、卷扫与网捕作用，对活性橙染料配水的色度去除率达到95%以上。
关键词：氢氧化镁；活性染料废水；搅拌；混凝；絮体中图分类号：X703.1 文献标志码：A 文章编号：1000–6613（2018）02–0761–06 DOI ：10.16085/j.issn.1000-6613.2017-0961Effects of mixing on magnesium hydroxide coagulation performance andfloc propertiesXIAO Shumin 1，2，ZHAO Jianhai 1，2，WEI Lei 1，2，CHI Yongzhi 1，2（1School of Environmental and Municipal Engineering ，Tianjin Chengjian University ，Tianjin 300384，China ；2TianjinKey Laboratory of Aquatic Science and Technology ，Tianjin 300384，China ）Abstract ：The effect of mixing conditions on the coagulation performance and floc properties of magnesium hydroxide was studied by the reaction of magnesium chloride in an alkaline condition and treatment of simulated reactive orange dyes wastewater. Based on the flocculation index （FI ）and the zeta potential ，the mechanism of floc formation was discussed ，and the floc morphology was observed to reveal the relationship between floc formation process and coagulation performance. The results showed that the rapid mixing time is favorable for floc formation ，and the optimum time is 45s. While longer rapid mixing time will result in floc broken and poor treatment effect. Similarly ，the best slow mixing time is 3min. Prolong mixing time will lead to floc broken. Using the optimum mixing time ，it was found that the mixing speed was also the main factor affecting the coagulation performance and floc properties. Lowering rapid and slow mixing speeds are not conducive to the formation and growth ，respectively. However ，higher mixing speed will make the floc broken and consequently reduce the treatment efficiency. When dosage of Mg 2+ is 150mg/L under laboratory conditions ，the optimum conditions for the coagulation performance of magnesium hydroxide were as follows ：rapid第一作者：肖淑敏（1979—），男，博士，副教授，研究方向为水污染控制。
偶氮染料废水生物处理方法研究进展
[11] Priya B, Uma L, Ahamed A K, et al. Ability to use the diazo dye C.I. Acid Black 1 as a nitrogen source by the marine cyanobacterium Oscillatoria curviceps BDU92191[J]. Bioresour Technol, 2011, 102(14): 7218-7223.
中图分类号：X791
文献标志码：B
文章编号：1673-040Fra bibliotek（2021）06-0062-03
偶氮染料是一种合成染料，在纺织、印染、 造纸、印刷等领域得到大量使用。目前，其使 用量达到总有机染料的 80％左右。据统计， 大约有高于 10%~15% 的偶氮染料释放到水环 境中。由于其具有较强抗光照和抗氧化的作 用，在水环境中能够持久存留，进一步带来水 体生态系统严重毁坏。此外，偶氮染料的“三 致”作用和生物抵抗性，引起其在环境中积聚 进一步对自然界的生物和人类健康带来威胁。 因此，偶氮染料的生物脱色和降解途径的研究 得到广大学者的广泛关注 [1]。本文主要介绍了 吸附脱色、常规生物法（包括好氧处理法、厌 氧处理法）、真菌技术、光合细菌法、藻类、 微生物燃料电池方法对偶氮染料的脱色及降 解途径。
参考文献 : [1] 卢婧 , 余志晟 , 张洪勋 . 微生物降解偶氮染料的研
究进展 [J]. 工业水处理 , 2013, 33(1):15-19. [2] 花莉 , 解井坤 , 朱超 , 等 . 微生物对偶氮染料脱色
Journal of Environmental Chemical Engineering
Characterization of nano zero-valent iron (nZVI) and its application in sono-Fenton process to remove COD in palm oil mill effluent
M.R. Taha a, A.H. Ibrahim b,*
This present study highlights the characterization of the nZVI particle and examines the effects of pH, ultrasound intensity (%), and ultrasound duration on the nZVI particle to produce Fe2+. Tests have also been conducted to analyze the application of the nZVI particle as a replacement for FeSO4 in the sono-Fenton process to remove chemical oxygen demand (COD) particularly in palm oil mill effluent (POME).
Journal of Environmental Chemical Engineering 2 (2014) 1–8
Contents lists available at ScienceDirect
Journal of Environmental Chemical Engineering
journal homepage: /locate/jece
The combination of ultrasound with the Fenton process (sono-
DIBAL-H选择还原酯基而不影响苄溴
1250J.Med.Chem.2010,53,1250–1260DOI:10.1021/jm901530bSynthesis and Structure-Activity Relationships of Azamacrocyclic C-X-C Chemokine Receptor4 Antagonists:Analogues Containing a Single Azamacrocyclic Ring are Potent Inhibitors of T-Cell Tropic(X4)HIV-1ReplicationGary J.Bridger,*,†Renato T.Skerlj,†,)Pedro E.Hernandez-Abad,‡David E.Bogucki,†Zhongren Wang,†Yuanxi Zhou,†Susan Nan,†Eva M.Boehringer,†Trevor Wilson,†Jason Crawford,†Markus Metz,†,)Sigrid Hatse,§Katrien Princen,§Erik De Clercq,§and Dominique Schols§†AnorMED Inc.now Genzyme Corporation,500Kendall Street,Cambridge,Massachusetts02142,‡Johnson Matthey Pharmaceutical Research,1401King Road,West Chester,Pennsylvania19380,and§Rega Institute for Medical Research,Katholieke Universiteit Leuven, Minderbroedersstraat10,B-3000Leuven,Belgium.)Genzyme Corp.,153Second Avenue,Waltham,Massachusetts02451.Received October15,2009Bis-tetraazamacrocycles such as the bicyclam AMD3100(1)are a class of potent and selective anti-HIV-1agents that inhibit virus replication by binding to the chemokine receptor CXCR4,the coreceptor for entryof X4viruses.By sequential replacement and/or deletion of the amino groups within the azamacrocyclic ringsystems,we have determined the minimum structural features required for potent antiviral activity in thisclass of compounds.All eight amino groups are not required for activity,the critical amino groups on a perring basis are nonidentical,and the overall charge at physiological pH can be reduced without compromisingpotency.This approach led to the identification of several single ring azamacrocyclic analogues such asAMD3465(3d),36,and40,which exhibit EC50’s against the cytopathic effects of HIV-1of9.0,1.0,and4.0nM,respectively,antiviral potencies that are comparable to1(EC50against HIV-1of4.0nM).Moreimportantly,however,the key structural elements of1required for antiviral activity may facilitate the designof nonmacrocyclic CXCR4antagonists suitable for HIV treatment via oral administration.IntroductionThe development of antiviral agents that inhibit alternative targets in the HIV a-replicative cycle remains an important goal in order to alleviate the side effects of currently approved agents or to overcome the problem of drug resistance.In this regard,we have focused on the development of compounds that inhibit CXCR4,the coreceptor used by T-tropic(T-cell tropic)viruses for fusion and entry of HIV into target cells of the immune system.The corresponding chemokine receptor CCR5is used by M-tropic(macrophage tropic)viruses and has been associated with the early stages of infection and replication in HIV-positive patients.1,2The transition from M-tropic to T-tropic(or dual/mixed-tropic)virus during the course of HIV infection in approximately50%of patients is associated with a faster CD4þT-cell decline and a more rapid disease progression.3-5Recently,we reported the results of clinical trials with our prototype CXCR4antagonist AMD31006-8(1)and an orally bioavailable CXCR4antagonist,(S)-N0-(1H-benzimidazol-2-ylmethyl)-N0-(5,6,7,8-tetrahydroquinolin-8-yl)butane-1,4-dia-mine(AMD070).9-11When administered to HIV positive patients whose virus was confirmed to use CXCR4for viral entry,both agents were able to suppress the replication of CXCR4and dual-tropic strains of HIV.Similarly,the CCR5 antagonist Maraviroc suppresses replication of HIV-1that exclusively uses CCR5for entry12and was recently approved by the FDA for combined antiretroviral therapy in treatment-experienced patients.13A combination of CCR5and CXCR4 antagonists for treatment of dual/mixed-tropic HIV infection is therefore highly desirable.Beyond its use as a coreceptor for HIV,the CXCR4 chemokine receptor has a more fundamental role in the trafficking of white blood cells,which broadly express CXCR4.14,15A member of the superfamily of G-protein coupled receptors,the interaction of CXCR4and its ligand, stromal cell-derived factor-1(SDF-1),plays a central role in the homing and retention of cells within the bone marrow microenvironment.16Consistent with these observations,ad-ministration of1to healthy volunteers caused a dose-depen-dent leukocytosis6,7that in subsequent studies was shown to include the mobilization of CD34þstem and progenitor cells suitable for hematopoietic stem cell transplantation.17-20The ability of analogues of1to mobilize progenitors correlated with their in vitro capacity to inhibit SDF-1binding to CXCR4.21Because of the need for parenteral administration, 1was developed in combination with granulocyte colony-stimulating factor(G-CSF)to mobilize hematopoietic stem cells to the peripheral blood for collection and subsequent autologous transplantation in patients with non-Hodgkin’s lymphoma(NHL)and multiple myeloma(MM).22-25Plerix-afor(1)was approved by the FDA in December2008.We have previously reported the structure-activity rela-tionships of anti-HIV bis-azamacrocycles and their transition*To whom correspondence should be addressed.Phone:617-429-7994.Fax:617-768-9809.E-mail:gary.bridger@.Ad-dress:Gary J.Bridger,Genzyme Corporation,55Cambridge Parkway,Cambridge MA02142.a Abbreviations:HIV,Human Immunodeficiency Virus;CXCR4,C-X-C chemokine receptor4;CCR5,C-C-R chemokine receptor5./jmc Published on Web12/31/2009r2009American Chemical SocietyArticle Journal of Medicinal Chemistry,2010,Vol.53,No.31251 metal complexes in detail.26-28Because of the commonstructural features between a doubly protonated cyclam(1,4,8,11-tetraazacyclotetradecane)ring present in1(at phy-siological pH)and a kinetically labile transition metal com-plex of cyclam with an overall charge ofþ2,we proposed thatboth structural motifs may bind to the CXCR4receptorthrough interactions with amino acid residues containingcarboxylate groups.29We have subsequently shown via direc-ted mutagenesis of the aspartate and glutamic acid residues inCXCR4that binding of1and related analogues to the seventransmembrane,G-protein coupled receptor is highly depen-dent upon the amino acids Asp171and Asp262,located intransmembrane region(TM)-IV and TM-VI at each end ofthe main ligand binding crevice of the receptor.30-35Mutationof either aspartic acid to aspargine significantly reduced theability of1to inhibit binding of radiolabeled stromal cellderived factor-1R(125I-Met-SDF-1R).More importantly,however,U87cells stably transfected with CD4and themutant coreceptors CXCR4[D171N]and CXCR4[D262N]were less effective at supporting infection of the CXCR4-usingHIV-1strain NL4.3compared to the wild-type receptor andthe double mutant CXCR4[D171N,D262N]completely failedas a coreceptor for HIV infection.31Correspondingly,theability of1to inhibit HIV-1infection via CXCR4[D171N]andCXCR4[D262N]was also diminished,thereby confirmingthat1binds in a region of the receptor that is critical for X4HIV-1coreceptor function.We have also reported that binding of the bis-Zn,Ni,andCu complexes of1were also dependent upon D171and D262of the receptor.36In a similar manner to1,the transitionmetal complexes were found to be less effective inhibitors of125I-Met-SDF-1R binding to the mutant receptors CXCR4-[D171N]and CXCR4[D262N]compared to the wild-typereceptor.Incorporation of Zn,Ni,or Cu into the cyclam ringsof1increased the affinity to the wild-type CXCR4receptor,but the enhancement was selectively eliminated by substitu-tion of Asp262.Supporting physiochemical evidence for theinteraction of acetate(carboxylates)with metal complexes ofazamacrocycles,including1,has been recently reported.37,38In the current study,we determine the minimum struc-tural features of1required for potent antiviral activity, leading to the identification of the single azamacrocyclic ring analogue AMD346532,33,39,40(3d)and ultimately the design of nonmacrocyclic,orally biovailable CXCR4an-tagonists.11,41,42Given the growing body of evidence that the CXCR4/SDF-1interaction is involved in regulating several human malignancies,43-45CXCR4antagonists may have additional therapeutic applications in addition to HIV treatment.ChemistryAnalogues containing a single1,4,8,11-tetraazacyclotetra-decane(cyclam)ring were prepared by modifications to previously published routes26,29as shown in Scheme1.Reac-tion of the selectively protected tris-diethylphosphoramidate (Dep)cyclam ring(2a)with R,R-dibromo-p-xylene in aceto-nitrile containing potassium carbonate gave the desired bro-momethyl intermediate(2b).Reaction of the bromide with an excess of the requisite amine,followed by deprotection of the Dep-groups with a saturated solution of hydrogen bromide in acetic acid at room temperature.gave analogues3a-i as the corresponding hydrobromide salts.To prepare analogues of3d in which the cyclam ring was replaced by a series of14-membered azamacrocyclic rings,we prepared a series of selectively protected macrocyclic ring systems containing a single(unprotected)secondary amine. This approach ensures the regiochemical outcome of the reaction with a benzylic halide during final construction (as shown in Scheme6).The syntheses of appropriate pre-cursors are shown in Schemes2-5.To incorporate fluorine groups at the desired position in the macrocyclic ring,suitably fluorinated bis-electrophiles were prepared,starting from 4-oxo-heptanedioic acid diethyl ester(4)and heptane-1,4,7-triol(8)as depicted in Scheme2.Reaction of the ketone(4) with neat(diethylamino)-sulfur trifluoride46,47(DAST)at room temperature for12days gave the corresponding di-fluoro-intermediate(5)in43%yield.Reduction of the ester groups with LAH(to give the diol6),followed by derivatiza-tion with toluenesulfonyl chloride,gave the bis-electrophile (7)required for the impending macrocyclization reaction.The corresponding monofluorinated intermediate was prepared in a similar manner.Protection of the primary alcohols in8as the acetyl group using acetic anhydride gave the secondary alcohol9,which was rapidly(and virtually quantitatively) converted to the fluorinated intermediate(10)with DAST (2.0equiv)in dichloromethane.Removal of the acetyl pro-tecting groups with saturated ammonia in methanol,followed by reaction of the diol(11)with p-toluenesulfonyl chloride, Scheme1aa Reagents:(a)R,R0-dibromo-p-xylene,K2CO3,CH3CN,reflux;(b)amine,K2CO3,CH3CN,reflux;(c)HBr,acetic acid,room temp. Scheme2aa Reagents:(a)Et2NSF3(neat),room temp;(b)LAH,Et2O;(c)Ts-Cl,Et3N,CH2Cl2;(d)acetic anhydride,pyridine;(e)Et2NSF3, CH2Cl2,-78°C,then room temp;(f)NH3/MeOH,room temp;(g)Ts-Cl,Et3N,CH2Cl2.1252Journal of Medicinal Chemistry,2010,Vol.53,No.3Bridger et al.gave the desired bis-electrophile 12containing a single fluorine group.The selectively protected azamacrocyclic rings were pre-pared via directed combinatorial macrocyclization of bis-2-nitrobenzenesulfonamides 48(Ns)(15a -c ,16a -c ,18)with bis-electrophiles (7,12,17)using previously optimized condi-tions 28(Scheme 3).To incorporate a phenyl or heterocyclic ring into the macrocycle,the corresponding bis-2-nitrobenze-nesulfonamide (15a -c )was prepared from the bis-aminoethyl intermediates 28(13a -c )by reaction with nosyl chloride (Et 3N,CH 2Cl 2).Similarly,16a ,b were obtained by reac-tion of commercially available intermediates 14a ,b with nosyl chloride or in the case of 16c (X=S)by reduction of 3,30-thiodipropionitrile with BH 33Me 2S and reaction of the intermediate diamine (14c )with nosyl chloride to give 16c .Macrocyclization was accomplished by dropwise addition of a DMF solution of the bis-electrophile to a DMF solution of the bis-2-nitrobenzenesulfonamide containing Cs 2CO 3maintained at a temperature of 80°C.Standard workup,followed by purification of the crude product by column chromatography on silica gel,gave the desired macrocycles 19a -c ,20a -c ,and 21a ,b in yields of 19-55%.Reaction of theintermediates from above with HBr/acetic acid at room temperature gave 22a -c ,23a -c ,and 24a ,b ,respectively.Because of synthetic convenience,we also prepared the selectively protected “isomers”of 22a ,b and 23a in which the alternative secondary amine was available for the alkylation reaction.We reasoned that reaction of 19a ,b and 20a with approximately 1equiv of thiophenol 49(our reagent of choice for nosyl deprotections)may allow pseudoselective deprotec-tion of a single nosyl group,leaving the Dep group intact.After some optimization,we found that reaction of 19a ,b and 20a with 0.8equiv of thiophenol and potassium carbonate in DMF (or acetonitrile)gave the precursors 25and 26a ,b in manageable,albeit modest yields (20-50%)following col-umn purification on silica gel (Scheme 4).Finally,the inter-mediates 27a ,b and 28(Scheme 5)were synthesized as recently described by palladium(0)catalyzed coupling of organozinc iodide reagents with bromopyridines.50Having completed the series of selectively protected aza-macrocycles,we proceeded to completion of the desired analogues by straightforward installation of the right-hand portion containing the aminomethyl pyridine moiety.As shown in Scheme 6,this was accomplished in all cases by direct alkylation of the available secondary amine of the macrocycle with the benzylic chlorides 34a ,b .Intermediate 34a was prepared in four steps from 4-bromomethyl benzoic acid methyl ester (29)and 2-aminomethylpyridine (31):con-version of 31to the 2-nitrobenzenesulfonamide 32,followed by alkylation with the benzyl bromide 30(obtained by reduc-tion of 29with DIBAL-H)gave the desired alcohol 33.As previously reported,28reaction of benzylic alcohols such as 33with methanesulfonyl chloride gave the chloride 34a rather than the corresponding mesylate,presumably via in situ nucleophilic substitution of the initially formed mesylate with chloride.Intermediate 34b (Scheme 6)containing a Dep-protecting group was prepared by an alternative synthesisScheme 3aaReagents:(a)Ns-Cl,Et 3N,CH 2Cl 2;(b)Cs 2CO 3,DMF,80°C;(c)HBr(g),AcOH,room temp.Scheme4Scheme5Article Journal of Medicinal Chemistry,2010,Vol.53,No.31253(procedures in Supporting Information).Alkylation of the available secondary amine of the macrocycles with 34a (or 34b )in CH 3CN in the presence of K 2CO 3gave the penultimate intermediates 35a -n .Deprotection of the nosyl groups with thiophenol and K 2CO 3in DMF gave the free base of the desired analogues,which in the vast majority of cases were converted to the corresponding hydrobromide salts.For analogues derived from the macrocyclic precursors 25and 26a ,b ,the intermediates isolated prior to the deprotection also contained a residual Dep group in addition to nosyl groups.For compound 45,we found that conversion to the hydro-bromide salt using a saturated solution of HBr in acetic acid resulted in concomitant deprotection of the remaining Dep group to obtain compound 45.For compounds 44and 46,the residual Dep group was removed prior to nosyl deprotection and salt formation.The thioether analogue 41a was also used to prepare the corresponding sulfoxide and sulfone analogues for antiviral evaluation as shown in Scheme 7.Initially,we globally protected the amino groups of 41a with Boc and subjected this intermediate to oxidation with oxone in MeOH 51at -10°C to give a mixture of the sulfoxide and sulfone that were separated by column chromatography on silica gel.However,while deprotection of the Boc groups with simulta-neous conversion to the hydrobromide salt proceeded without incident for the sulfone (to give 41c ),we found that deprotec-tion of the corresponding sulfoxide led to substantial reduc-tion and hence recovery of the starting analogue 41a .To overcome this problem,the sulfoxide was synthesized by direct oxidation of 41a with 1equiv of oxone in MeOH to give 41b in a 21%isolated yield and was subsequently tested as the free base in antiviral assays.Finally,we prepared a short series of analogues containing a carbon atom in place of a tertiary nitrogen group at the ring junction.To economize on the number of synthetic steps,weelected to synthesize the dimesylate 54(Scheme 8),an inter-mediate that could be commonly used for the synthesis of multiple analogues via macrocylization with the bis-2-nitro-benzenesulfonamide precursors already in our possession (namely 15a ,16a ,b from Scheme 3).Intermediate 54was prepared from the commercially available starting material bromo-p -tolunitrile via a double one-carbon homologation of the malonate 51,followed by derivatization to gave the requisite bis-methanesulfonate 54.Macrocyclizations of 54with bis-sulfonamides 15a and 16a ,b were performed as described above.Deprotection of the nosyl groups followed by conversion to the corresponding hydrobromide salts gave analogues 56and 58a ,b .DiscussionHaving previously established the optimum ring size and distance between the amines of both aliphatic andScheme 6a aReagents:(a)DIBAL-H,CH 2Cl 2;(b)Ns-Cl,Et 3N,CH 2Cl 2;(c)K 2CO 3,CH 3CN,60°C;(d)Ms-Cl,Et 3N,CH 2Cl 2;(e)K 2CO 3,CH 3CN,80°C;(f)R =Ns:thiophenol,K 2CO 3,DMF,or R =Dep:HBr(g),AcOH,room temp.Scheme 7aaReagents:(a)oxone,MeOH,-10°C;(b)(Boc)2O,THF;(c)HBr(g),AcOH,room temp.Scheme 8aaReagents:(a)NaH,R -bromo-tolunitrile,THF;(b)LiAlH 4,THF;(c)Ns-Cl,Et 3N,CH 2Cl 2;(d)2-picolyl chloride,Et 3N,K 2CO 3,KBr,CH 3CN,reflux;(e)Ms-Cl,Et 3N,CH 2Cl 2;(f)cetyltrimethyammonium bromide,NaCN,benzene,H 2O,reflux;(g)conc HCl/AcOH (4:1),reflux;(h)BH 3.Me 2S,THF;(i)Ms-Cl,Et 3N,CH 2Cl 2;(j)Cs 2CO 3,DMF,80°C;(k)thiophenol,K 2CO 3,CH 3CN (or DMF),40°C.1254Journal of Medicinal Chemistry,2010,Vol.53,No.3Bridger et al.pyridine-fused bis-tetraazamacrocycles required for potent X4anti-HIV activity,we designed a series of compounds to address the question of structural redundancy.The prototype bis-macrocycle 1has a center of symmetry and contains eight amino groups,of which four are positively charged at phy-siological pH.In the current study,we aimed to answer two specific questions:(1)Are all four positive charges required for potent anti-HIV activity?(2)On a per ring basis,what are the minimum structural requirements for activity?Assuming that the structural requirements are not iden-tical for both rings of 1,we reasoned that the simplest replacement for a single tetraaza-macrocyclic ring would be a pseudo diamine-segment,representing the first two amino groups of the macrocyclic ring from the point of attachment at the benzylic position.A judicious choice of “diamine”would also reduce the overall charge to þ1.Having previously established that the optimum distance between the first two amino groups was a two-carbon unit,we prepared a series of aminomethyl-substituted analogues in which the second amino group was a substituent upon an aromatic ring or part of a heterocyclic ring.In either case,the second p K a would be sufficiently low to prevent a second protonation at physiological pH.The compounds were tested for their ability to inhibit replication of HIV-1III B in MT-4cells,a strain of HIV-1that uses exclusively CXCR4for fusion and viral entry into target cells.The results are shown in Table 1.Compared to 1,the introduction of a benzylamine group (3a )in place of the azamacrocyclic ring substantially reduced anti-HIV potency,although the compound remained active at submicromolar concentrations.The concentration of 3a re-quired to inhibit HIV-1replication by 50%(the EC 50)was 0.49μM,which was approximately 100-fold higher than the 50%inhibitory concentration of 1.Aromatic amino groups at the 2-position (3b )or 4-position (3c )did not affect antiviral potency.Both 3b ,c exhibited comparable EC 50’s to the un-substituted benzyl group (3a ).However,we observed a sub-stantial increase in anti-HIV potency when the benzyl group was replaced by a pyridyl group (3d ).Compound 3d exhibited a 50%inhibitory concentration of 0.009μM,which was only ca.2-fold higher than the EC 50of 1.Furthermore,the 50%cytotoxic concentration (CC 50)of compound 3d in MT-4cells was greater than 112μM.Thus 3d exhibits a selectivity index of greater than 12000.The positional specificity of the pyridine-N in 3d was also examined.Replacement of the 2-pyridyl group with the 3-pyridyl (3e )or 4-pyridyl (3f )group had a detrimental effect on anti-HIV potency.For example,the EC 50’s of analogues 3e ,f were approximately 3orders of magnitude higher than the concentration of 3d required to inhibit HIV-1replication by 50%(the EC 50’s of 3e and 3f were 8.470and 9.977μM,respectively).Methylation of the amine in 3d (to give 3g )or extension of the connectivity to an aminoethyl pyridine group (to give 3h )also adversely affected the anti-HIV potency.Finally,we replaced the pyridine moiety with a comparable heterocycle of lower p K a than pyridine,namely the pyrazine group (3i ).Perhaps not surprisingly,the antiviral potency of analogue 3i was approximately comparable to the benzyl analogue 3a ,which did not contain a vicinal heterocycle nitrogen atom.With the optimized “right-hand”replacement for the aza-macrocycle ring of 1fixed as the 2-aminomethyl pyridine group,we then turned our attention to the “left-hand”ring.Needless to say,the mandatory synthesis of the symmetrical analogue in which both rings were replaced by a 2-amino-methyl pyridine group turned out to be a predictably fruitless exercise (EC 50was >250μM,data not shown).We therefore focused on systematically replacing individual amine groups of the left ring.As shown in Table 2,we first prepared an analogue in which the [14]aneN 4(cyclam)ring had been replaced by the optimized and equally suitable,py[iso -14]-aneN 4ring (to give compound 36).Consistent with the structure -activity relationship of py[iso -14]aneN 4bis-azama-crocycles,compound 36proved to be a potent inhibitor of HIV-1replication,exhibiting an EC 50of 0.001μM,that is,around 9-fold and 4-fold lower,respectively,than the con-centration of 3d or 1required to inhibit viral replication by 50%.Although the pyridine-N of the macrocyclic ring in 36was previously found to be critical for high antiviral potency,we reasoned that a precise determination of the pyridine-N contribution to potency could help redesign a less basic pounds 37and 38were then prepared to answer this question.Both analogues 37,containing a phenyl replacement and 38,containing an “exocyclic”pyridine fused group,retained reasonable anti-HIV potency (the EC 50’s of 37and 38were 0.040and 0.104μM,respectively)but were at least 40-to 100-fold less potent than analogue 36.So what role does the pyridine group play?At physiological pH,the overall charge of the py[iso -14]-aneN 4ring in 36is also þ2(in a similar manner to cyclam 52)and the likely protonation sequence is indicated in Figure 1A,based on the sequence reported by Delgado et al.53for similar 14-membered tetraazamacrocyclic rings contain-ing pyridine.Presumably,the secondary amino groups are predominantly protonated and the overall structure is stabi-lized by intramolecular hydrogen bond interactions from the adjacent hydrogen-bond acceptors,the pyridine and tertiary benzylic amine groups (while minimizing the elec-trostatic repulsion of two positive charges in a confined macrocyclic ring).This is confirmed by a conformational analysis of 36on B3LYP/6-31G*level followed by single point energy calculations.In the energetically most stable ring conformation (LMP2/6-311þG*þZPE),the pyridine nitro-gen forms two six-membered intramolecular hydrogen bond interactions with the two adjacent protonated nitrogens as shown in Figure 2.Potential five-membered intramolecular hydrogen bond interactions are formed with the tertiary amine.Table 1.Antiviral Activity of Single RingAzamacrocyclesnR 1R 2HIV-1(III B )EC 50(μM)MT-4cells CC 50(μM)3a 1H Ph0.4911603b 1H 2-amino-Ph 1.825243c 1H 4-amino-Ph 0.7172273d 1H 2-pyridine 0.009>1123e 1H 3-pyridine 8.470373f 1H 4-pyridine 9.977>2793g 1Me 2-pyridine 0.416383h 2H 2-pyridine 49.135>1103I 1H5-Me-pyrazine1.8957810.004>421ArticleJournal of Medicinal Chemistry,2010,Vol.53,No.31255The stabilization provided by this “shared”protonated structure could account for the high basicity of azamacrocyc-lic rings,as suggested by Kimura et al.54It did not seem unreasonable,therefore,that a potential role of the pyridine group is the contribution of a single intramolecular hydrogen-bond,which locks the conformation of the protonated aza-macrocyclic ring in manner that is beneficial to antiviral potency.To test this hypothesis,we prepared a series of analogues (depicted in Figure 1B,data in Table 2)in which the fused aromatic group had been removed and replaced by an aliphatic group,in some cases containing a hydrogen-bondacceptor at the key position “x,”the position occupied by the pyridine nitrogen in compound 36.Consistent with the hydrogen-bonding hypothesis,the alkyl analogue 39exhibited an anti-HIV potency that was compar-able to the phenyl and exocyclic pyridine analogues 37and 38(the EC 50’s of 37and 39,were 0.040and 0.043μM,re-spectively).This result categorically rules out the possibility that the conformational restrictions imposed by the fused aromatic groups in compounds 37,38were even partially responsible for the high potency of 36.However,incorpora-tion of a hydrogen-bond acceptor at position x (Figure 1B)in some cases restored activity comparable to 36.For example,the oxygen analogue 40exhibited an EC 50that was only 4-fold higher than the concentration of 36required to inhibit HIV-1replication by 50%(the EC 50of 40was 0.004μM).The corresponding thioether analogue 41a exhibited an EC 50of 0.013μM,which is approximately 3-fold higher than com-pound 40.Although the antiviral potency of the thioether analogue 41a compared to the ether analogue 41is greater than one would predict from the strength of the hydrogen-bond acceptor acceptor capabilities (thioether groups are considerably weaker H-bond acceptors than the oxygen inTable 2.Antiviral Activity of Single RingAzamacrocyclesFigure 1.Proposed hydrogen-bond structure of protonated aza-macrocycles.1256Journal of Medicinal Chemistry,2010,Vol.53,No.3Bridger et al.40),this result can be reconciled by considering the nature of the H-bond required;a six-membered intramolecular H-bond constrained by the macrocyclic ring (Figure 2).With the thioether compound 41a in hand,we also pre-pared the sulfoxide (41b )and sulfone (41c )analogues by direct oxidation of 41a .We reasoned that the oxygen atoms of the sulfoxide and sulfone are stronger H-bond acceptors than the sulfur atom of 41a and may consequently improve the anti-HIV potency.However,both 41b and 41c were considerably weaker antiviral agents,exhibiting 50%effective concentra-tions for inhibition of HIV-1replication that were at least 79-fold higher than the EC 50of 41a (the EC 50’s of 41b and 41c were 0.485and 11.878μM,respectively).The precise reason for the poor antiviral activity exhibited by analogues 41b ,c was unclear;although the sulfoxide and sulfone are more sterically demanding than the thioether and could induce a ring conformation that is detrimental to antiviral activity,we could not rule out the possibility that the H-bond acceptor oxygen is now “one-bond”outside of the ring,and the intramolecular H-bond itself induces an unfavorable confor-mation (a seven-membered ring H-bond in 41b ,c (Figure 2)compared to a six-membered in 41a ).To complete this series of compounds therefore,we decided to introduce the fluoro and difluoro substituents at position x (Figure 1B).Several reports have demonstrated that the fluoro group can partici-pate as an acceptor for intramolecular H-bonds,particularly within highly constrained ring structures.55-57This is also confirmed by our calculations,as shown in Figure 2.The fluoro (43)and difluoro (42)analogues were also attractive substituents for two other reasons:(1)the substituents would be situated at the fourth carbon from the adjacent amine group,thereby minimizing the affect on p K a ;(2)in a similar manner to the sulfoxide and sulfone,the H-bond acceptor would be one-bond outside of the macrocyclic ring.However in this case,because the fluorine atom in C -F groups is isostructural with hydrogen,a negative effect of the fluoro substituents on antiviral activity can only be attributed to an inappropriately positioned H-bond rather than steric requirements (that is,in the absence of an H-bond,we would expect the fluoro or difluoro analogues to exhibit an EC 50comparable to the methylene analogue 39).In antiviral test-ing,the fluoro (43)and difluoro (42)analogues displayed EC 50’s that were greater than 20-fold higher than the methy-lene analogue 39(the EC 50’s of 39,42,and 43were 0.043,0.920,and 1.239μM,respectively),confirming the negative consequences of an incorrectly positioned hydrogen-bond (Figure 2).Next,we focused on the sequence of aliphatic amine groups in the macrocyclic ring required for potent antiviral activity.By straightforward synthetic manipulation of our collection of ring systems,we prepared the structural isomers of analo-gues 36,37,and 39in which the side-chain (R,in Table 2)was connected to the alternative secondary amine group to give compounds 44,45,and 46.In antiviral testing,analogue 44was substantially less potent than its corresponding regioi-somer 39:the EC 50of 44was 11.131μM,which was approxi-mately 260-fold higher than the EC 50of 39.A similar loss of antiviral potency was observed with the phenyl analogue 46and its isomer 37(the EC 50’s of 46and 37were 14.106and 0.040μM,respectively).Interestingly,the loss of antiviral potency with the pyridine-fused isomer 45compared to 36was significant but not as substantial;the EC 50of 45was 0.063μM,around 60-fold higher than the concentration of 36required to inhibit HIV-1replication by 50%.There was a possibility,therefore,that while the “tri-aza”ring configura-tion required for potent antiviral activity is clearlyrepresentedFigure 2.Lowest energy conformations of compounds 36,40,41c ,and 42.View from top on a plane defined by three nitrogens and X (see Figure 1).Dashed lines indicate hydrogen bond interactions:the hydrogen bond acceptors in 36and 40are in one plane with the three nitrogens.This is not the case for 41c and 42.Bond angles:36:—(N 333H -N þ)=140.5°,122.4°,102.1°,108.4°.40:—(O 333H -N þ)=135.1°,141.5°;—(N 333H -N þ)=104.6°,102.8°.41c :—(O 333H -N þ)=112.8°,112.8°;—(N 333H -N þ)=108.2°,108.0°.42:—(F 333H -N þ)=142.2°,142.2°;—(N 333H -N þ)=114.7°,114.7°.。
Biodecolorization and partial mineralization of Reactive Black 5 by a strain of Rhodopseudomonas
Intrபைடு நூலகம்duction
R ea ctive a zo dye s ar e wide ly used a s textile colora nts, typica lly for cotton dye ing, due to their varie ty of c olor sha des, high we t fastness profi les, ease of a pplica tion, br illiant c olor s, a nd m inim al e nergy c onsumption. They a pproxim ately ac count for up to 70% of the total dyestu ff pr oduced (C ar liell e t al ., 1995; Lee e t al ., 2004). However, a s m uch a s 20%–50% of the initia l re active dye s are w ashed o ff in the dyeing proc ess r esulting fr om their e asy hydr olyz ation and c onse quential low affi nity for the fi ber, the ref ore, they r em ain in the dye bath e ffl uents ( Sopa et al ., 2000). Apa rt f rom the a esthetic conc erns, the dye c ontaining e ffl uents ma y cause se rious problem s since the c leavage of azo bonds produce s a rom atic am ines, whic h a re considere d muta genic and c ar cinogenic ( Hu, 2001; O ’Ne ill e t al ., 2000). M a ny physic oche mic al m ethods ha ve be en em ploye d to tre at textile wa ste water for decoloriz ation and de toxifi ca tion, which inc lude s adva nced oxida tion proce sses ( such a s the use of Fe nton re agent, hydrogen pe roxide or oz one) , coa gula tion- floc culation, ac tivated c arbon adsor ption, m e mbr ane filtration, ion e xchange , irr adiation, a nd e lectr okine tic c oagulation. Howeve r, alm ost none of the se tre atm ents ar e ver y f ea sibile, due to either high running c ost or huge che m ic al sludge produc tion (S en a nd Dem irer, 2003) .
欧洲药典7.5版
INDEX
To aid users the index includes a reference to the supplement in which the latest version of a text can be found. For example : Amikacin sulfate...............................................7.5-4579 means the monograph Amikacin sulfate can be found on page 4579 of Supplement 7.5. Note that where no reference to a supplement is made, the text can be found in the principal volume.
English index ........................................................................ 4707
Latin index ................................................................................. 4739
EUROPEAN PHARMACOPபைடு நூலகம்EIA 7.5
Index
Numerics 1. General notices ................................................................... 7.5-4453 2.1.1. Droppers...................
LED专业名词中英文对照
1 backplane 背板2 Band gap voltage reference 带隙电压参考3 benchtop supply 工作台电源4 Block Diagram 方块图5 Bode Plot 波特图6 Bootstrap 自举7 Bottom FET Bottom FET8 bucket capcitor 桶形电容9 chassis 机架10 Combi-sense Combi-sense11 constant current source 恒流源12 Core Sataration 铁芯饱和13 crossover frequency 交叉频率14 current ripple 纹波电流15 Cycle by Cycle 逐周期16 cycle skipping 周期跳步17 Dead Time 死区时间18 DIE Temperature 核心温度19 Disable 非使能，无效，禁用，关断20 dominant pole 主极点21 Enable 使能，有效，启用22 ESD Rating ESD额定值23 Evaluation Board 评估板24 Exceeding the specifications below may result in permanentdamage to the device, or device malfunction. Operation outside of theparameters specified in the Electrical Characteristics section is notimplied.超过下面的规格使用可能引起永久的设备损害或设备故障。
建议不要工作在电特性表规定的参数范围以外。
25 Failling edge 下降沿26 figure of merit 品质因数27 float charge voltage 浮充电压28 flyback power stage 反驰式功率级29 forward voltage drop 前向压降30 free-running 自由运行31 Freewheel diode 续流二极管32 Full load 满负载33 gate drive 栅极驱动34 gate drive stage 栅极驱动级35 gerber plot Gerber 图36 ground plane 接地层37 Henry 电感单位：亨利38 Human Body Model 人体模式39 Hysteresis 滞回40 inrush current 涌入电流41 Inverting 反相42 jittery 抖动43 Junction 结点44 Kelvin connection 开尔文连接45 Lead Frame 引脚框架46 Lead Free 无铅47 level-shift 电平移动48 Line regulation 电源调整率49 load regulation 负载调整率50 Lot Number 批号51 Low Dropout 低压差52 Miller 密勒53 node 节点54 Non-Inverting 非反相55 novel 新颖的56 off state 关断状态57 Operating supply voltage 电源工作电压58 out drive stage 输出驱动级59 Out of Phase 异相60 Part Number 产品型号61 pass transistor pass transistor62 P-channel MOSFET P沟道MOSFET63 Phase margin 相位裕度64 Phase Node 开关节点65 portable electronics 便携式电子设备66 power down 掉电67 Power Good 电源正常68 Power Groud 功率地69 Power Save Mode 节电模式70 Power up 上电71 pull down 下拉72 pull up 上拉73 Pulse by Pulse 逐脉冲（Pulse by Pulse）74 push pull converter 推挽转换器75 ramp down 斜降76 ramp up 斜升77 redundant diode 冗余二极管78 resistive divider 电阻分压器79 ringing 振铃80 ripple current 纹波电流81 rising edge 上升沿82 sense resistor 检测电阻83 Sequenced Power Supplys 序列电源84 shoot-through 直通，同时导通85 stray inductances. 杂散电感86 sub-circuit 子电路87 substrate 基板88 Telecom 电信89 Thermal Information 热性能信息90 thermal slug 散热片91 Threshold 阈值92 timing resistor 振荡电阻93 Top FET Top FET94 Trace 线路，走线，引线95 Transfer function 传递函数96 Trip Point 跳变点97 turns ratio 匝数比，＝Np / Ns。
贝克曼库尔特 Vero 细胞宿主细胞蛋白免疫酶联免疫吸附试验盒用于测量 Vero 细胞宿主细胞蛋白说
Vero Cell Host Cell Proteins Immunoenzymetric Assay for the Measurement of Vero Cell Host Cell ProteinsCatalog # F500Intended UseThis kit is intended for use in determining the presence of host cell protein impurities in products manufactured by expression in Vero cells. The kit is for Research and Manufacturing Use Only and is not intended for diagnostic use in humans or animals.Summary and ExplanationExpression of viral vaccines and other therapeutic proteins in Vero cells is a cost effective method for production of commercial quantities of a drug substance. The manufacturing and purification process of these products leaves the potential for impurities by host cell proteins (HCPs) from Vero cells. Such impurities can reduce the efficacy of the therapeutic agent and result in adverse toxic or immunological reactions and thus it is desirable to reduce HCP impurities to the lowest levels practical.Immunological methods using antibodies to HCPs such as Western Blot and ELISA are conventionally accepted. While Western blot is a useful method aiding in the identity of HCPs, it suffers from a number of limitations. Western blot is a complex and technique dependent procedure requiring subjective interpretation of results. Furthermore, it is essentially a qualitative method and does not lend itself to obtaining quantitative answers. The sensitivity of Western blot is severely limited by the volume of sample that can be tested and by interference from the presence of high concentrations of the intended product. While Western Blot may be able to detect HCPs in samples from upstream in the purification process, it often lacks adequate sensitivity and specificity to detect HCPs in purified downstream and final product. The microtiter plate immunoenzymetric assay (ELISA) method employed in this kit overcomes the limitations of Western blots providing on the order of 100 fold better sensitivity. This simple to use, objective, and semi-quantitative ELISA is a powerful method to aid in optimal purification process development, process control, routine quality control, and product release testing. This kit is “generic” in the sense that it is intended to react with essentially all of the HCPs that could pollute the product independent of the purification process. The antibodies have been generated against and affinity purified using mild lysate of Vero cells. The resulting antibodies have then been characterized against four commercial cell lines used to produce various viral and protein products. This analysis indicated the vast majority of HCPs are conserved among multiple Vero cell lines and product purification processes. If you have a need of a more sensitive method to demonstrate coverage to HCPs in your process Cygnus Technologies recommends a method that is superior to Western blot called Antibody Affinity Extraction (AAE). AAE is has greatly increased sensitivity and specificity to Western blot which makes it a better predictor of how the antibodies will perform in the ELISA. For additional information on AAE please visit our website and read the posted articles under Technical Documents or contact our Technical Services Department.Special procedures were utilized in the generation of these antibodies to ensure that low molecular weight and less immunogenic impurities as well as high molecular weight components would be represented. As such, this kit can be used as a process development tool to monitor the optimal removal of host cell impurities as well as in routine final product release.This highly sensitive ELISA kit has been qualified for testing of final product HCPs using actual in-process and final drug substance samples from 4 vaccine products all with somewhat different growth and purification processes. Each user of this kit is encouraged to perform a similar qualification study to demonstrate it meets their analytical needs. Provided this kit can be satisfactorily qualified for your samples, the application of a more process specific assay may not be necessary, in that such an assay would only provide information redundant to this generic assay. However, if your qualification studies indicate the antibodies in this kit are not sufficiently reactive with your process specific HCPs it may be desirable to also develop a more process specific ELISA. This later generation assay may require the use of a more specific and defined antisera. Alternatively, if the polyclonal antibody used in this kit provides sufficient sensitivity and broad antigen reactivity, it may be possible to substitute the standards used in this kit for ones made from the impurities that typically co-purify through your purification process and thus achieve better accuracy for process specific HCPs. The use of a process specific assay with more defined antigens and antibodies in theory may yield better specificity, however such an assay runs the risk of beingtoo specific in that it may fail to detect new or atypical impurities that might result from some process irregularity or change. For this reason it is recommendedth at a broadly reactive “generic” host cell protein assay be used as part of the final product purity analysis even when a process specific assay is available. If you deem a more process specific assay is necessary, Cygnus Technologies is available to apply its proven technologies to develop such antibodies and assays on custom basis.The Vero cell assay is a two-site immunoenzymetric assay. Samples containing Vero cell HCPs are reacted simultaneously with a horseradish peroxidase (HRP) enzyme labeled anti-Vero cell antibody (goat polyclonal) in microtiter strips coated with an affinity purified capture goat polyclonal anti-Vero cell antibody. The immunological reactions result in the formation of a sandwich complex of solid phase antibody-HCP-enzyme labeled antibody. The microtiter strips are washed to remove any unbound reactants. The substrate, tetramethylbenzidine (TMB) is then reacted. The amount of hydrolyzed substrate is read on a microtiter plate reader and is directly proportional to the concentration of Vero cell HCPs present.Storage & Stability•All reagents should be stored at 2︒C to 8︒C for stability until the expiration date printed on the kit. •After prolonged storage, you may notice a salt precipitate and/or yellowing of the washconcentrate. These changes will not impact assayperformance. To dissolve the precipitate, mix thewash concentrate thoroughly and dilute asdirected in the ‘Preparation on Reagents’ section. •Reconstituted wash solution is stable until the expiration date of the kit. •Microtiter plate reader spectrophotometer with dual wavelength capability at 450 & 650nm. (Ifyour plate reader does not provide dualwavelength analysis you may read at just the450nm wavelength.)•Pipettors - 50μL and 100μL•Repeating or multichannel pipettor - 100μL •Microtiter plate rotator (400 - 600 rpm) •Sample Diluent (recommended Cat # I028) •Distilled water• 1 liter wash bottle for diluted wash solution•For Research or Manufacturing use only. •Stop reagent is 0.5M H2SO4. Avoid contact with eyes, skin, and clothing.•This kit should only be used by qualified technicians.•Bring all reagents to room temperature. •Dilute wash concentrate to 1 liter in distilled water, label with kit lot and expiration date, and store at4︒C.Assay Protocol•The assay is very robust such that assay variables like incubation times, sample size, and othersequential incubation schemes can be altered tomanipulate assay performance for moresensitivity, increased upper analytical range, orreduced sample matrix interference. Beforemodifying the protocol from what is recommended,you are advised to contact Technical Services forinput on the best way to achieve your desiredgoals.•The protocol specifies use of an approved orbital microtiter plate shaker for the immunologicalsteps. These can be purchased from mostlaboratory supply companies. If you do not havesuch a device, it is possible to incubate the platewithout shaking however, it will be necessary toextend the immunological incubation step in theplate by about one hour in order to achievecomparable results to shaking protocol. Do notshake during the 30-minute substrateincubation step, as this may result in higherbackgrounds and worse precision.800-F500, Rev. 3, 26DEC2019 Vero Cell HCP ELISA Product Insert 2•Bring all reagents to room temperature. Set-up plate spectrophotometer to read dual wavelengthat 450nm for the test wavelength and ~650nm forthe reference.•Thorough washing is essential to proper performance of this assay. Automated platewashing systems or other vacuum aspirationdevices are not recommended. The manualmethod described in the assay protocol ispreferred for best precision, sensitivity andaccuracy. A more detailed discussion of thisprocedure can be obtained from our TechnicalServices Department or on our web site. Inaddition, a video demonstration of proper platewashing technique is available in the ‘TechnicalHelp’ section of our we b site.•All standards, controls, and samples should be assayed at least in duplicate.•Maintain a repetitive timing sequence from well to well for all assay steps to ensure that all incubationtimes are the same for each well.•Make a work list for each assay to identify the location of each standard, control, and sample. •It is recommended that your laboratory assay appropriate quality control samples in each run toensure that all reagents and procedures arecorrect. You are strongly urged to makecontrols in your typical sample matrix usingHCPs derived from your cell line. Thesecontrols can be aliquoted into single use vialsand stored frozen for long-term stability.•If the substrate has a distinct blue color prior to assay it may have been contaminated. If theabsorbance of 100μL of substrate plus 100μL ofstop against a water blank is greater than 0.1 itmay be necessary to obtain new substrate or thesensitivity of the assay may be compromised. •Strips should be read within 30 minutes after adding stop solution since color will fade over time.Limitations•Before relying exclusively on this assay to detect host cell proteins, each laboratory should qualifythat the kit antibodies and assay procedure yieldacceptable specificity, accuracy, and precision. Asuggested protocol for this qualification can beobtained from our Technical Services Departmentor our web site.•The standards used in this assay are comprised of Vero cell HCPs solubilized by methods commonlyused in initial harvesting steps for vaccineproducts. 1D Western blot analysis of theantibodies used in this kit demonstrates that theyrecognize the majority of distinct PAGE separatedbands seen using sensitive protein stainingmethods like silver stain or colloidal gold. Becausethe majority of HCPs will show sufficient antigenicconservation among all lines of Vero cells this kitshould be adequately reactive to HCPs from yourcell line. However, there can be no guarantee thatthis assay will detect all proteins or proteinfragments from your process. If you desire a much800-F500, Rev. 3, 26DEC2019 Vero Cell HCP ELISA Product Insert 3more sensitive method than western blot to detectthe reactivity of the antibodies in this kit to yourindividual HCPs Cygnus Technologies is pleasedto perform AAE as a service to provide coverageinformation of the antibodies to the HCPs in yourprocess samples.•Certain sample matrices may interfere in this assay. The standards used in this kit attempt tosimulate typical sample protein and matrices.However, the potential exists that the product itselfor other components in the sample matrix mayresult in either positive or negative interference inthis assay. High or low pH, detergents, urea, highsalt concentrations, and organic solvents are someof the known interference factors. It is advised totest all sample matrices for interference by dilutingthe 200ng/mL standard, 1 part to 4 parts of thematrix containing no or very low HCP impurities.This diluted standard when assayed as anunknown, should give an added HCP value in therange of 30 to 50 ng/mL. Consult CygnusTechnologies Technical Service Department foradvice on how to quantitate the assay inproblematic matrices.•Avoid the assay of samples containing sodium azide (NaN3) which will destroy the HRP activity ofthe conjugate and could result in the under-estimation of HCP levels.1. Complete washing of the plates to remove excess unreacted reagents is essential to good assay reproducibility and sensitivity. We advise against the use of automated or other manually operated vacuum aspiration devices for washing plates as these may result in lower specific absorbances, higher non-specific absorbance, and more variable precision. The manual wash procedure described below generally provides lower backgrounds, higher specific absorbance, and better precision. If duplicate CVs are poor, or if the absorbance of the 0 standard is greater than 0.200, evaluate plate washing procedure for proper performance.2. High Dose Hook Effect or poor dilutional linearity may be observed in samples with very high concentrations of HCP. High Dose Hook Effect is due to insufficient excess of antibody for very high concentrations of HCPs present in samples upstream in the purification process. Samples greater than 1 mg/mL may give absorbances less than the 200 ng/mL standard. It is also possible for samples to have certain HCPs in concentrations exceeding the amount of antibody for that particular HCP. In such cases the absorbance of the undiluted sample may be lower than the highest standard in the kit, however these samples will fail to show acceptable dilutional linearity/ parallelism as evidenced by an apparent increase in dilution corrected HCP concentration with increasing dilution. High Dose Hook and poor dilutional linearity are most likely to be encountered from samples early in the purification process. If a hook effect is possible, samples should also be assayed diluted. If the HCP concentration of the undiluted sample is less than the diluted sample this may be indicative of the hook effect. Such samples should be diluted at least to the minimum required dilutions (MRDs) as established by your qualification studies using your actual final and in-process drug samples. The MRD is the first dilution at which all subsequent dilutions yield the same HCP value within the statistical limits of assay precision. The HCP value to be reported for such samples is the dilution corrected value at or greater than the established MRD. The diluent used should be compatible with accurate recovery. The preferred diluent is our Cat# I028 available in 100mL, 500mL, or 1 liter bottles. This is the same material used to prepare the kit standards. As the sample is diluted in I028, its matrix begins to approach that of the standards, thus reducing any inaccuracies caused by dilutional artifacts. Other prospective diluents must be tested for non-specific binding and recovery by using them to dilute the 200ng/mL standard, as describ ed in the “Limitations” section below.•Precision on duplicate samples should yield average % coefficients of variation of less than10% for samples in the range of 8-200ng/mL. CVsfor samples less than 8 ng/mL may be greaterthan 10%.•It is recommended that each laboratory assay appropriate quality control samples in each run toensure that all reagents and procedures arecorrect.The standards may be used to construct a standard curve with values reported in ng/m L “total immuno-reactive HCP equivalents”. This data reduction may be performed through computer methods using curve fitting routines such as point-to-point, cubic spline, or 4 parameter logistic fit. Do not use linear regression analysis to interpolate values for samples as this may lead to significant inaccuracies! Data may also be manually reduced by plotting the absorbance values of the standard on the y-axis versus concentration on the x-axis and drawing a smooth point-to-point line. Absorbances of samples are then interpolated from this standard curve.800-F500, Rev. 3, 26DEC2019 Vero Cell HCP ELISA Product Insert 4800-F500, Rev. 3, 26DEC2019 Vero Cell HCP ELISA Product Insert 5Performance CharacteristicsCygnus Technologies has qualified this assay by conventional criteria as indicated below. A copy of this qualification report can be obtained on our web site or by request. This qualification is generic in nature and is intended to supplement but not replace certain user and product specific qualification and qualification that should be performed by each laboratory. At a minimum each laboratory is urged to perform a spike and recovery study in their sample types. In addition, any of your samples types containing process derived HCPs within or above the analytical range of this assay should be evaluated for dilutional linearity to ensure that the assay is accurate and has sufficient antibody excess for your particular HCPs. Each laboratory and technician should also demonstrate competency in the assay by performing a precision study similar to that described below. A more detailed discussion of recommended user qualification protocols can be obtained by contacting our Technical Services Department or at our web site.SensitivityThe lower limit of detection (LOD ) is defined as that concentration corresponding to a signal two standard deviations above the mean of the zero standard. LOD is ~0.7 ng/mL.The lower limit of quantitation (LOQ ) is defined as the lowest concentration, where concentration coefficients of variation (CVs) are less than 20%. The LOQ is less than 2 ng/mL.PrecisionBoth intra (n=20 replicates) and inter-assay (n=10 assays) precision were determined on 3 pools with low (~8ng/mL), medium (~25ng/mL), and high concentrations (~75ng/mL). The % CV is the standard deviation divided by the mean and multiplied by 100.Specificity/Cross-Reactivity1D Western blot and ELISA analysis against 4commercial Vero cell strains indicate that most of the proteins are conserved among all cell lines. Therefore, this assay should be useful for detecting HCPs from other Vero cell lines. Western blot, both 1 & 2dimensional, is highly orthogonal to ELISA and to non-specific protein staining methods such as silver stain or colloidal gold. As such, the lack of identity between silver stain and western blot does not necessarily mean there is not antibody to that protein or that the ELISA will not detect that protein. If you desire a much more sensitive and specific method than western blot to detect the reactivity of the antibodies in this kit to your individual HCPs Cygnus Technologies is pleased to perform AAE as a service to provide coverage information of the antibodies to the HCPs in your process samples. This method has been shown to be much more sensitive and specific than Western blots in detecting antibody reactivity to individual HCPs. The same antibody as is used for both capture and HRP label can be purchased separately as Cat# VC 807-AF.Cross reactivity to non-HCP components has not been extensively investigated with this kit. You should evaluate components in your samples for positive interferences such as cross reactivity and non-specific binding. Negative interference studies are described below.Recovery/ Interference StudiesVarious buffer matrices commonly used in purification and final formulation of drug substances expressed in Vero cells were evaluated by adding known amounts of Vero cell HCP preparation used to make the standards in this kit. Because this assay is designed to minimize matrix interference most of these buffers yielded acceptable recovery defined as between 80-120%. The standards used in this kit contain 8mg/mL of bovine serum albumin intended to simulate non-specific protein affects of most sample proteins or virus products. However very high concentrations of some products may interfere in the accurate measurement of HCPs. In general, extremes in pH (less than 5.0 and greater than 8.5), high salt concentration, high polysaccharide concentrations, and most detergents can cause under-recovery. Each user should qualify that their sample matrices yield accurate recovery. Such an experiment can be performed, by diluting the 200ng/mL standard provided with this kit, into the sample matrix in question as described in the “Limitations” section. CygnusTechnologies offers a more concentrated form of theHCP (Cat # F503H at 100μg/mL) used to prepare thekits standards for your spike recovery and preparation ofanalyte controls.Hook CapacityIncreasing concentrations of HCPs greater than 200ng/mL were assayed as unknowns. The hook capacity,defined as that concentration yielding an absorbancereading less than the 200 ng/mL standard was greaterthan 1000 μg/mL.Cygnus Technologies also offers kits for the extractionand detection of CHO Host Cell DNA. The following kitsare available:•Residual Host Cell DNA extraction:Cat # D100W, DNA Extraction Kit in 96 deep well plateCat # D100T, DNA Extraction Kit in microfuge tubesTo place an order or to obtain additional productinformation contact Cygnus Technologies:Cygnus Technologies, LLC4332 Southport Supply Rd. SESouthport, NC 28461 USATel: 910-454-9442Email for all Order inquiries:*****************************Email for Technical Support:**********************************_____________________________________________800-F500, Rev. 3, 26DEC2019 Vero Cell HCP ELISA Product Insert 6。
净化净化处理 英语
净化净化处理英语Purification Processes: An Insight into Water and Air Treatment.Purification, a term often associated with the removal of impurities, is crucial in maintaining the quality of our environment and resources. From water purification to air purification, the processes involved aim to ensure the safety and suitability of these resources for human consumption and use. Let's delve into the intricacies of these purification methods, discussing their importance, techniques, and applications.Water Purification.Water, being the essence of life, demands meticulous purification to ensure its purity and safety for consumption. Water purification processes aim to remove harmful contaminants, microorganisms, and other impurities that may pose a threat to human health.1. Sedimentation.Sedimentation is the first step in water purification, where larger particles such as sand, silt, and other solids settle down at the bottom of the treatment tank due totheir heavier weight. This process helps remove most of the visible impurities from the water.2. Coagulation and Flocculation.Coagulation involves adding chemicals to the water, which neutralize the negative charges on the suspended particles, causing them to aggregate or clump together. Flocculation follows, where the clumps formed in coagulation grow larger and heavier, facilitating their removal in the subsequent processes.3. Filtration.In this stage, the water passes through a filter media, such as sand or activated carbon, which traps the remainingsuspended particles and removes them from the water. This process significantly improves the clarity of the water.4. Chlorination.Chlorination is a common disinfection method used tokill bacteria, viruses, and other microorganisms in the water. Chlorine or its compounds are added to the water, which reacts with the organic and inorganic matter, killing the microorganisms present.5. Ozonation.Ozonation is an alternative disinfection method that uses ozone, a highly reactive form of oxygen. Ozone is more effective than chlorine in killing microorganisms, as it does not form harmful by-products like chlorinated organic compounds.6. UV Disinfection.UV disinfection uses ultraviolet light to killmicroorganisms in the water. The UV light disrupts the genetic material of the microorganisms, rendering them inactive and unable to reproduce.Air Purification.Air purification processes aim to remove harmful particles, gases, and microorganisms from the air, improving its quality and making it safer to breathe.1. Mechanical Filtration.Mechanical filters, such as screens or mesh, are used to trap larger particles like dust, hair, and pollen. These filters are effective in removing particles larger than their pore size.2. Adsorption.Adsorption is a process where gases or vapors adhere to the surface of a solid adsorbent material, such as activated carbon. Activated carbon has a high surface areaand adsorption capacity, making it effective in removing odors, volatile organic compounds (VOCs), and other gases from the air.3. Ion Exchange.Ion exchange involves the replacement of ions in a solution with ions of a different type, which are held by an ion exchange resin. This process is used to remove harmful ions, such as chloride or sulfate, from the air.4. UV Germicidal Irradiation.UV germicidal irradiation uses ultraviolet light tokill microorganisms in the air, similar to UV disinfection in water treatment. UV light destroys the genetic material of microorganisms, rendering them inactive.5. Photocatalytic Oxidation.Photocatalytic oxidation uses a photocatalyst, such as titanium dioxide (TiO2), and UV light to oxidize anddecompose organic compounds in the air. This process is effective in removing VOCs, odors, and other harmful organic compounds.6. Electronic Air Cleaners.Electronic air cleaners use electrostatic precipitation to remove particles from the air. These devices charge the particles passing through them, causing them to adhere to collector plates, which are then cleaned periodically.In conclusion, purification processes play a crucial role in ensuring the safety and suitability of water andair for human consumption and use. The techniques discussed in this article, including sedimentation, coagulation and flocculation, filtration, chlorination, ozonation, UV disinfection, mechanical filtration, adsorption, ion exchange, UV germicidal irradiation, photocatalytic oxidation, and electronic air cleaners, are just a few of the many purification methods available. Each method hasits own advantages and applications, and it's important tochoose the right purification process based on the specific needs and conditions of the treatment facility.。
活性黑5染料模拟废水电解脱色探究
活性黑5染料模拟废水电解脱色探究魏杰;宗刚;李婉莹【期刊名称】《当代化工》【年(卷),期】2018(47)3【摘要】为明确活性黑5染料在电化学体系中的脱色过程,以石墨为阴极,Ti/PbO2为阳极,考察了电流大小、初始pH值、电解质种类及浓度、电解时间、温度、染料初始浓度对染料脱色过程的影响.结果表明:电流大小、氯化钠浓度对活性黑5脱色率影响较大,一定条件下染料脱色率可达99%;初始pH对染料脱色率几乎无影响,随着初始pH在4~10范围内变化,脱色率始终稳定在99%以上;染料的脱色率随着电解时间的增加而增大,当电解时间达到60 min时,染料脱色率达到99%.%In order to clarify the decolorization process of reactive black 5 dye in electrochemical system, using graphite as the cathode and usingTi/PbO2as the anode, the effect of current value, initial pH value, electrolyte type and concentration, electrolysis time, electrolysis temperature and initial dye concentration on the decolorization process was investigated. The experimental results showed that: the current value, the concentration of sodium chloride had great effect on the decolorization rate of reactive black 5, the decolorization rate reached 99% under a certain condition;The initial pH had little effect on the decolorization rate of the dye, and the decolorization rate was always above 99% under the initial pH of 4 ~ 10;The decolorization rate of the dyeincreased with the increase of the electrolysis time. When the electrolysis time was 60 min, the decolorization rate of the dye reached 99%.【总页数】4页(P505-508)【作者】魏杰;宗刚;李婉莹【作者单位】西安工程大学,环境与化学工程学院,陕西西安 710048;西安工程大学,环境与化学工程学院,陕西西安 710048;西安法士特汽车传动有限公司,陕西西安710119【正文语种】中文【中图分类】X788【相关文献】1.活性染料模拟废水电化学脱色 [J], 杨蕴哲2.铝阳极电凝聚处理活性黑KN-B染料模拟废水 [J], 杨蕴哲;胡筱敏;梁吉艳3.铁炭微电解-微波激发无极紫外光处理活性红195染料模拟废水 [J], 赵晖;孙杰;曾庆福4.Fenton法脱色降解活性黑5模拟废水 [J], 林桐枫;胡筱敏;杨蕴哲5.W/W型PAM乳液对活性翠兰K-GL染料模拟废水脱色性能的研究 [J], 董士华;刘晓东;黄诚;王辉;杜宗良;成煦因版权原因，仅展示原文概要，查看原文内容请购买。
基于PMS的Cr(VI)-染料复合废水协同处理效果及机理
基于PMS的Cr(VI)-染料复合废水协同处理效果及机理闫松; 张成武; 李天一; 秦传玉【期刊名称】《《中国环境科学》》【年(卷),期】2019(039)008【总页数】6页(P3271-3276)【关键词】染料废水; 复合污染; 过一硫酸盐; Cr(VI); 协同处理【作者】闫松; 张成武; 李天一; 秦传玉【作者单位】吉林大学地下水资源与环境教育部重点实验室吉林长春 130012; 吉林大学新能源与环境学院吉林长春 130012【正文语种】中文【中图分类】X703印染废水成分复杂,不仅含有大量难降解的偶氮染料,还有以氯化钠为主的无机盐[1]以及滚筒剥铬产生的含铬物质,是典型的含盐含铬有机废水.对于Cr(VI)或染料废水的单独处理技术已经相对成熟,而对于Cr(VI)-染料复合污染的协同处理研究报道较少,相对于生物法[2-4]及物理吸附法[5-6]耗时长、处理效果差等缺点,化学法展现出了见效快且效果好等优点;有学者利用零价铁还原Cr(VI)同时零价铁与氧气反应在有配体存在下生成高活性自由基降解染料,但该方法成本较高且容易生成大量铁泥[7-8];利用光催化二氧化钛也可以同时降解染料及Cr(VI)[9-10],但Cl-会竞争TiO2表面的活性吸附位点从而影响光催化氧化,且会改变TiO2的空间结构使TiO2失活[11-13].因此寻找一种低成本且在Cl-存在下仍可以有效处理Cr(VI)-染料复合污染的方法具有重要意义.近年来有文献报道Cl-可以活化过一硫酸盐(PMS)产生活性物质降解污染物[14-16];同时过渡金属离子如Fe2+、Co2+、Mn2+、Ce3+等[17-18]可以活化PMS产生硫酸根自由基(SO4·—),Cr(VI)作为一种过渡金属已被报道可以活化H2O2产生羟基自由基(×OH)[19],而PMS与H2O2具有相似的结构且氧化还原电位相近(分别为+1.82V(PMS)和+1.77V (H2O2))[20],因此考虑Cr(VI)是否具有活化PMS降解污染物的潜力,从而通过在含盐含铬染料废水中添加PMS达到同时去除染料和Cr(VI)的目的.本文通过添加氯化钠、重铬酸钾、代表性偶氮染料AO7来模拟含盐含铬染料废水,加入PMS研究该体系协同处理偶氮染料AO7及Cr(VI)的可行性、影响因素及反应机理.过硫酸氢钾(KHSO5×0.5KHSO4×0.5K2SO4),金橙II(上海阿拉丁生化科技股份有限公司);重铬酸钾(99.8%,天津市光复科技发展有限公司);氯化钠,氢氧化钠,硫酸,磷酸(分析纯,北京化工厂);二苯碳酰二肼(分析纯,国药集团化学试剂有限公司);叔丁醇,硫酸铵(化学纯,国药集团化学试剂有限公司);乙醇(分析纯,天津天泰精细化学品有限公司);甲醇(分析纯,西陇科学股份有限公司).HZK-210电子天平(福州华志科学仪器有限公司), YSI pH100pH计(美国黄泉仪器有限公司), HJ- 6A数显恒温磁力搅拌器(金坛市医疗仪器厂), EVOLUTION 201紫外分光光度计(Thermo Fisher Scientific - Shanghai), SPECTRONIC 200E可见分光光度计(Thermo Fisher Scientific - Shanghai), Thermo TSQ三重串联四级杆质谱仪.所有实验通过使用250mL锥形瓶在室温(25±2)℃下进行;向特定浓度的AO7水溶液中依次加入一定量的重铬酸钾及氯化钠,置于磁力搅拌器上搅拌,转速控制在500r/min左右;加入所需量的PMS进行反应,在反应期间不控制pH值;在特定的时间间隔取出样品并立即分析.每组实验重复三次,最终结果取平均值.Cr(VI)浓度测定采用二苯碳酰二肼分光光度法 [21]; AO7浓度测定采用直接分光光度法,于484nm处有特征吸收峰;AO7中间产物采用LC-MS测定,采取手动进样,洗脱液为乙腈,流速为0.2mL/min,采用负离子扫描模式在m/z为40~200范围内获得MS光谱.应用Excel2010、OriginPro8.0进行数据分析处理与作图.对比不同组分体系中AO7的降解率及Cr(VI)的去除率,结果如图1所示.PMS单独降解AO7在120min内效率仅为3.2%,几乎不降解;PMS/Cr(VI)、PMS/Cl-以及PMS/Cr(VI)/Cl-体系均可以降解AO7, 120min时降解率分别达到58.8%、88.9%及97.9%;反应结束后Cr(VI)转化为毒性更低的Cr(III),PMS/ Cr(VI)及PMS/Cr(VI)/Cl-体系Cr(VI)去除率可分别达到35.9%及22.1%.由上述结果可知,PMS与Cl-反应可以有效降解AO7,Cr(VI)同时存在可以提高AO7的降解效率,且Cr(VI)自身可以达到一定程度的去除.2.2.1 Cl-浓度对体系降解的影响分别选取浓度为5.6,14,28mmol/L 的Cl-进行实验,结果如图2所示.随着Cl-浓度增加,AO7降解效率逐渐升高,120min时AO7降解率分别达到56.5%、88.9%及99.1%;虽然28mmol/L的Cl-体系降解效率较高,但其在60min已接近反应完全,不方便后续研究,因此选取14mmol/L作为实验Cl-浓度进行后续研究.2.2.2 初始pH值对体系降解的影响有文献报道碱可以直接活化PMS产生活性物质降解污染物[22],为避免碱性条件干扰体系降解AO7的实验结果,仅探究酸性条件下初始pH值的变化对于体系降解AO7的影响,结果如图3所示.初始pH值在4.5及6.5的条件下AO7的降解率仍能达到97.9%,因此酸性条件下PMS/Cl-体系对AO7的降解效率基本不受初始pH值的影响.2.2.3 HClO掩蔽剂对体系降解的影响 Wang等 [23]考察Cl-对Co2+/PMS体系降解AO7的研究中发现较高浓度的Cl-可以活化PMS生成活性氯与AO7反应,且有研究表明NH4+不能被SO4·—和×OH 氧化,但是可以与HClO发生反应生成活性较低的NH2Cl、NHCl2和NCl3[24-26],因此选用硫酸铵作为HClO掩蔽剂进行掩蔽实验,结果如图4所示.不添加掩蔽剂时体系降解效率为88.9%;添加15mmol/L硫酸铵后体系降解效率降低至43.5%;添加150mmol/L硫酸铵后体系降解效率降低至3.4%,与PMS单独降解效率相近.因此说明该体系中AO7的降解是HClO的作用.2.3.1 初始pH值对体系降解的影响当PMS溶于水时显酸性,pH值可以达到3以下,为考察酸性条件在体系降解AO7中的作用,将PMS/Cr(VI)体系与酸性条件下单独Cr(VI)降解AO7进行对比,并调节不同初始pH值探究其对体系降解效果的影响,结果如图5所示.初始pH值为2.5时Cr(VI)可以单独降解AO7,降解效率与PMS/Cr(VI)体系降解效率相近,说明PMS/Cr(VI)体系降解AO7是由于PMS溶于水创造的酸性条件使得Cr(VI)具有强氧化性进而直接氧化AO7;随着pH值的升高AO7的降解率逐渐降低,pH值为4.5时AO7几乎不降解,表明PMS/Cr(VI)降解AO7的反应仅在3以下时效果较好.2.3.2 自由基掩蔽剂对体系降解的影响为验证Cr(VI)是否能够活化PMS产生活性自由基,使用叔丁醇作为×OH掩蔽剂,乙醇作为×OH及SO4·—的共同掩蔽剂进行掩蔽实验,结果如图6所示.2种掩蔽剂对于体系降解均无明显影响,说明Cr(VI)并不能活化PMS产生活性自由基,结合2.3.2实验结果可以说明AO7的降解是酸性条件下Cr(VI)的强氧化性导致的.徐蕾[27]等人研究发现,在常温条件下Cl-可以与PMS发生非自由基反应生成活性氯,其反应方程如下:本研究中2.2.3实验结果验证了这一机理,同时2.3实验结果表明,Cr(VI)不能活化PMS产生活性自由基,而是由于PMS/Cl-体系创造的酸性条件使得Cr(VI)具有强氧化性,在氧化AO7的同时实现自身向低毒性Cr(III)的转化.由于在PMS/Cr(VI)/Cl-体系中Cr(VI)与活性物质HClO均能降解AO7,因此可以通过计算两部分对AO7降解的贡献占比来确定体系中起主要作用的活性物质.计算过程如下:通过PMS/ Cr(VI)体系中AO7降解及Cr(VI)去除量计算得出单位浓度Cr(VI)消耗对应的AO7降解量,再通过PMS/Cr(VI)/Cl-体系中Cr(VI)的消耗量计算得出对应的AO7降解量,AO7的降解总量除去因Cr(VI)氧化降解的量剩余为HClO 氧化降解的量;计算结果如下:PMS/ Cr(VI)/Cl-体系降解AO7的反应中,HClO氧化降解的部分占70.8%,Cr(VI)氧化降解的部分占29.2%.综上所述,PMS/Cr(VI)/Cl-体系中AO7的降解是由于Cl-与PMS反应产生氧化性物质HClO以及PMS投加创造的酸性条件使得Cr(VI)具有强氧化性的共同作用,其中起主导作用的是HClO;Cr(VI)的转化是由自身与AO7发生氧化还原反应导致的. 为探究PMS/Cr(VI)/Cl-体系降解AO7的途径进行中间产物的测定,测定结果见表1,根据测定结果推测的AO7降解途径见图7.如图7所示,反应中AO7的-N=N-优先被打开从而使染料脱色,AO7被分解为对氨基苯磺酸钠及1-氨基-2-萘酚;随后对氨基苯磺酸钠可以被氧化成对苯酚及1,2,4苯三酚,同时磺基脱下形成甲基磺酸;1-氨基-2-萘酚可以被氧化形成1-硝基-2-萘酚及2-萘酚,随后萘环被破坏生成多种苯系物;沿着对氨基苯磺酸钠及1-氨基-2-萘酚2条路径氧化最终均生成苯系物,且苯环无法进一步被打开.为探究体系降解AO7的矿化程度在反应前后进行TOC测定,测定结果反应前后TOC无明显变化,说明体系降解AO7无法达到矿化,与中间产物测定结果相同. 3.1 单独PMS在120min内对AO7基本无降解,PMS/Cr(VI)、PMS/Cl-以及PMS/Cr(VI)/Cl-体系均可以有效降解AO7,120min时降解率分别达到58.8%、88.9%及97.9%;PMS/Cr(VI)以及PMS/Cr (VI)/Cl-体系中Cr(VI)去除率分别可达到35.9%及22.1%.3.2 初始pH值对PMS/Cl-体系降解AO7无明显影响.PMS/Cr体系在降解AO7的同时Cr(VI)自身可以转化为Cr(III);随着pH值降低AO7及Cr(VI)去除率逐渐升高,pH值在3以下反应效果较好.3.3 PMS/Cr(VI)/Cl-体系中AO7的降解主要是强氧化性物质HClO以及Cr(VI)的共同作用,其中起主导作用的是HClO;Cr(VI)的转化是由自身与AO7发生氧化还原反应导致的.3.4 反应过程中AO7的-N=N-键首先被破坏从而使染料脱色,且随着反应进行萘环可以被破坏但苯环无法被进一步打开,体系反应前后TOC值不变,不能达到矿化.【相关文献】[1] 郭建博.高盐染料废水的生物降解及介提强化作用研究 [D]. 大连:大连理工大学, 2005. Guo JB. Biodegradation of hyper-salinity dye wastewaters and the accelerating effect of redox mediators [D]. Dalian: Dalian University of Technology, 2005.[2] 张禄艳,王竞,吕红,等.高盐条件下染料酸性橙7的生物降解特性 [J]. 中国环境科学, 2009,29(6):640-645. Zhang LY, Wang J, Lv H, et al. Biodegradation characteristics of Acid Orange 7under hypersaline conditions [J]. China Environmental Science, 2009,29(6):640-645.[3] Liu W, Liu C, Liu L, et al. Simultaneous decolorization of sulfonated azo dyes and reduction of hexavalent chromium under high salt condition by a newly isolated salt-tolerant strain Bacillus circulans BWL1061 [J]. Ecotoxicology and Environmental Safety, 2017,141: 9-16.[4] Hussain S, Quinn L, Li J, et al. Simultaneous removal of malachite green and hexavalent chromium by Cunninghamella elegans biofilm in a semi-continuous system [J]. International Biodeterioration & Biodegradation, 2017,125:142-149.[5] Anwar F, Hussain S, Ramzan S, et al. Characterization of Reactive Red-120Decolorizing Bacterial Strain Acinetobacter junii FA10Capable of Simultaneous Removal of Azo Dyes and Hexavalent Chromium [J]. Water, Air, & Soil Pollution,2014,225:1-16.[6] 方伟.改性石墨烯/聚吡咯复合材料对水中Cr(VI)及刚果红的吸附研究 [D]. 广州:华南理工大学, 2018. Fang W. Research on Adsorption of hexavalent chromium and CongoRed in aqueous solutions onto modified graphene/pyrrole composite materials [D]. Guangzhou: South China University of Technology, 2018.[7] Kyzas G Z, Lazaridis N K, Kostoglou M. On the simultaneous adsorption of a reactive dye and hexavalent chromium from aqueous solutions onto grafted chitosan [J]. Journal of Colloid And Interface Science, 2013,407:432-441.[8] Fu F, Han W, Tang B, et al. Insights into environmental remediation of heavy metal and organic pollutants: Simultaneous removal of hexavalent chromium and dye from wastewater by zero-valent iron with ligand-enhanced reactivity [J]. Chemical Engineering Journal, 2013,232:534-540.[9] Kim S A, Kamala-Kannan S, Oh S, et al. Simultaneous removal of chromium(VI) and Reactive Black 5using zeolite supported nano- scale zero-valent iron composite [J]. Environmental Earth Sciences, 2016,75:1-8.[10] Xie W, Zhang M, Liu D, et al. Photocatalytic TiO2/porous BNNSs composites for simultaneous LR2B and Cr (VI) removal in wool dyeing bath [J]. Journal of Photochemistry and Photobiology A: Chemistry, 2017,333:165-173.[11] Djellabi R, Ghorab M, Sehili T. Simultaneous Removal of Methylene Blue and Hexavalent Chromium From Water Using TiO2/Fe(III)/ H2O2/Sunlight [J]. CLEAN-SOIL AIR WATER, 2017:45.[12] Suzuko Y, Atsushi Y, Hiroyuki A. Photocatalytic degradation of chloroform in the gas phase on the porous TiO2 pellets: effect of Cl- accumulated on the catalyst surface [J]. Journal of Photochemistry and Photobiology A: Chemistry, 2005,169(2):191-196.[13] Cardoso J C, Lizier T M, Zanoni M V B. Highly ordered TiO2 nanotube arrays and photoelectrocatalytic oxidation of aromatic amine [J]. Applied Catalysis B: Environmental, 2010,99(1/2):96-102.[14] Vogtenhuber D, Podloucky R, Redinger J. Ab initio study of atomic Cl- dsorption on stoichiometric and reduced rutile TiO2 (110) surfaces [J]. Surface Science, 2000,(454-456):369-373.[15] 古振川,高乃云,安娜,等.Cl-/PMS体系降解甲氧苄啶的效能与机理 [J]. 中国环境科学, 2018,38(3):977-984. Gu Z C, Gao N Y, An N, et al. Efficiency and mechanism of trimethoprim degradation in Cl-/PMS system [J]. China Environmental Science,2018,38(3):977-984.[16] 张珂,许芬,陈家斌,等.丙酮/氯离子协同活化过一硫酸盐降解酸性橙 [J]. 中国环境科学, 2018,38(11):4159-4165. Zhang K, Xu F, Chen JB, et al. Acetone and chloride ion synergistically activate peroxymonosulfate to decolorize acid orange [J]. China Environmental Science, 2018,38(11):4159-4165.[17] 谈超群,董雨婕,钟毅杰,等.新型氯离子活化过氧单硫酸盐的非自由基系统去除水中扑热息痛的研究 [J]. 四川大学学报(自然科学版), 2018,55(4):819-826. Tan C Q, Dong Y J, Zhong Y J, et al. Acetaminophen degradation with non-radical based reactive oxidants generated by chloride activated peroxymonosulfate system [J]. Journal of Sichuan University (NaturalScience Edition), 2018,55(4):819-826.[18] Liang C J, Bruell C J, Marley M C, et al. Persulfate oxidation for in situ remediation of TCE. I Activated by ferrous ion with and without a persulfate-thiosulfate redox couple [J]. Chemosphere, 2004,55(9): 1213-1223.[19] Anipsitakis G P, Dionysiou D D. Degradation of organic contaminants in water with sulfate radicals generated by the conjunction of peroxymonosulfate with cobalt [J]. Environmental Science and Technology, 2003,37(20):4790-4797.[20] Asadi A, Dehghani MH, Rastkari N, et al. Comparison of potentiality of Zinc oxide nanoparticles and hydrogen peroxide in removal of hexavalent chromium from polluted water [J]. Journal of Birjand University of Medical Sciences, 2012,19:277-285.[21] GB/7467-87 水质六价铬的测定二苯碳酰二肼分光光度法 [S]. GB/7467-87 Water quality-Determination of chromium(VI) - 1,5diphenylcarbohydrazide spectrophotometric method [S].[22] Betterton E A, Hoffmann M R. Kinetics and mechanism of the oxidation of aqueous hydrogen sulfide by peroxymonosulfate [J]. Environmental Science and Technology, 1990,24(12):1819-1824.[23] 葛勇建,蔡显威,林翰,等.碱活化过一硫酸盐降解水中环丙沙星 [J]. 环境科学,2017,38(12):5116-5123. Ge Y J, Cai X W, Lin H, et al. Base activation of peroxymonosulfate for the degradation of ciprofloxacin in water [J]. Environmental Science, 2017,38(12):5116-5123.[24] Wang Z H, Yuan R X, Guo Y G, et al. Effects of chloride ions on bleaching of azo dyes by Co2+/oxone regent: Kinetic analysis [J]. Journal of Hazardous Materials, 2011,190(1–3):1083-1087.[25] Deborde M, Gunten U V. Reactions of chlorine with inorganic and organic compounds during water treatment-Kinetics and mechanisms: A critical review [J]. Water Research, 2008,42(1/2):13-51.[26] Yang S Y, Wang P, Yang X, et al. Degradation efficiencies of azo dye Acid Orange7by the interaction of heat,UV and anions with common oxidants: Persulfate, peroxymonosulfate and hydrogen peroxide [J]. Journal of Hazardous Materials,2010,179:552-558.[27]徐蕾,袁瑞霞,郭耀广,等.氯离子对钴/单过氧硫酸盐体系降解2,4,6-三氯苯酚的影响 [J]. 武汉大学学报理学版, 2013,59(1):51- 56. Xu L, Yuan R X, Guo Y G, et al. Effects of chloride ions on degradation of 2,4,6-trichlorophenol by Co(II)/peroxymonosulfate (Co/PMS) system [J]. Journal of Wuhan University (Natural Science Edition), 2013,59(1):51-56.。
Fenton技术中残余组分对COD测定的干扰和消除研究
Fenton技术中残余组分对COD测定的干扰和消除研究刘生宝;刘芬;蓝明菊【摘要】Fenton试剂与水样中难降解有机物反应后,残余组分会对后续水样COD 测定产生干扰.实验表明,Fenton试剂残余组分中H2O2对COD测定产生的干扰较大,其对水样COD测定产生的影响值与H2O2浓度成良好的线性关系,而残余组分Fe2+对COD测定产生的干扰与H2O2相比,影响值较小,可忽略其影响.通过对比分析掩蔽剂法、催化分解法对H2O2干扰消除试验得出,掩蔽剂Na2SO3能够迅速的与H2O2发生反应,消除H2O2的干扰,但掩蔽剂Na2SO3也会对水样COD 产生一定的干扰,测量结果偏差较大;MnO2催化分解H2O2的效率较高,很好的消除H2O2的干扰,但MnO2分解后水样COD测定值需乘以折减系数0.89,满足试验精度的要求;过氧化氢酶可以将H2O2完全分解,分解效率较高,干扰消除效果较好.【期刊名称】《当代化工》【年(卷),期】2016(045)006【总页数】4页(P1152-1155)【关键词】Fenton技术;二氧化锰;催化分解;过氧化氢酶【作者】刘生宝;刘芬;蓝明菊【作者单位】石河子大学,新疆石河子832000;石河子大学,新疆石河子832000;石河子大学,新疆石河子832000【正文语种】中文【中图分类】O657Fenton技术作为水处理领域中一种常用的高级氧化技术，广泛应用于含难生化降解有机物废水的处理[1-4]。
Fenton试剂以H2O2为氧化剂，在Fe2+的催化作用下产生羟基自由基。
羟基自由基具有非常高的氧化还原电位，氧化有机物的能力较强[5-10]。
Fenton技术的优点在于分解速度快、氧化速率高，可以将难降解有机污染物完全矿化。
COD是表征水体受有机物污染的重要参数，在水质检测中应用广泛[11-14]。
目前COD测定多采用重铬酸钾法，芬顿氧化反应后残余组分H2O2和Fe2+在重铬酸钾存在的条件下表现出一定的还原性，在强酸性溶液中会被重铬酸钾氧化[13-16]，对COD的测定结果产生影响，干扰处理效果评价。
石墨烯及其复合材料在水处理中的应用_肖蓝.
5 Conclusions and outlook
1 引言
石墨烯（ graphene，GE ） 是 一 种 由 sp2 杂 化 的 碳
原子以六边形排列形成的周期性蜂窝状二维碳质新 材料［1］。2004 年，英国曼彻斯特 大 学 物 理 和 天 文 学 系的 Geim 和 Novoselov 等［2］用胶带剥离石墨晶体首 次获得了石墨烯，并由此获得了 2010 年诺贝尔物理 学奖。石墨烯物理 化 学 性 质 独 特，是 世 界 上 最 坚 固 的材料之一［3］，理论比 表 面 积 高 达2 630 m2 / g［4］，具 有 良 好 的 导 热 性［5］ 和 高 速 的 电 子 迁 移 率 （ 200 000cm2 / （ V·s） ） ［6］，可 作 为 电 极 材 料、传 感 器、储氢 材 料［7］。 同 时，用 于 制 备 石 墨 烯 及 其 复 合 材 料 的 石 墨 来 源 广 泛 ，石 墨 烯 及 其 复 合 材 料 ，相 比 碳 纳米管，价格较低 廉，制 备 过 程 简 单，许 多 学 者 开 始 研究石墨烯及其复 合 材 料 在 水 处 理 中 的 应 用［8—10］。 图 1 为单层石墨烯分子模型。
石墨 烯 的 制 备 方 法 主 要 有 微 机 械 剥 离 法 （ micromechanical cleavage ） ［12］、化 学 气 相 沉 积 法 （ chemical vapor deposition ） ［13］、晶 体 外 延 生 长 法 （ epitaxial growth ） ［14］、胶 体 悬 浮 液 法 （ colloidal suspension） ［15］等。在水处 理 中 应 用 的 石 墨 烯，考 虑
· 420 ·
化学进展
第 25 卷
金属有机骨架材料活化过硫酸盐高级氧化体系深度处理造纸废水
金属有机骨架材料活化过硫酸盐高级氧化体系深度处理造纸废水谢全模; 万金泉; 马邕文; 王艳【期刊名称】《《科学技术与工程》》【年(卷),期】2019(019)028【总页数】5页(P406-410)【关键词】造纸废水; 深度处理; MOFs活化; 硫酸根自由基; 响应曲面法【作者】谢全模; 万金泉; 马邕文; 王艳【作者单位】华南理工大学环境与能源学院广州 510006; 东莞市亿鼎环保工程有限公司东莞 523000; 中新国际联合研究院广州 510006【正文语种】中文【中图分类】X703造纸工业是国民经济发展的支柱产业,2016年中国造纸产量突破1.2×108 t,产值1.4万亿元,居世界首位。
但同时造纸工业废水又是中国主要的工业污染源,其排放量占工业废水总排放量30%以上、化学需氧量(COD)排放量占40%以上。
造纸废水污染物成分复杂且含有大量难降解有机污染物,使得造纸废水经过二级生化处理后常常存在COD浓度偏高,无法达到制浆造纸工业水污染物排放标准,需要进一步深度处理[1]。
高级氧化法在处理难降解有机废水具有极大的应用价值,目前造纸废水深度处理主要采用Fenton高级氧化技术,通过具有强氧化性羟基自由基降解有机污染物,但该方法存在需要pH为3.0～5.0的酸性条件,操作复杂,处理成本高,铁泥产生量大等问题[2,3]。
因此,探索一种高效的造纸废水深度处理技术,实现造纸废水COD的超低排放尤为重要。
近年来,过硫酸盐(PS)因其价格较低,稳定性好,可以提供高氧化电位的硫酸根自由基有效氧化降解有机污染物而受到越来越普遍的关注。
由于在酸性、中性、弱碱性条件均能有效地降解污染物,因而在难降解有机废水应用方面更为广泛[4—6]。
采用过渡金属催化活化是PS产生自由基最主要的方式,但由于催化剂活性中心位点难以控制,导致的产生速率无法得到控制,从而使得PS氧化体系中的副反应较多,的有效利用率低等。
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
1. Introduction
The effluents discharged from textile, paper, printing, and leather industries contain a large variety of reactive dyes, and these dyes are of great environmental concern due to their huge applications and toxic nature [1]. Azo reactive dyes represent
Please cite this article as: S. Chatterjee, S.-Rn. Lim, S.H. Woo, Removal of Reactive Black 5 by zero-valent iron modified with various surfactants, Chemical Engineering Journal (2008), doi:10.1016/j.cej.2010.02.045 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Davis, 3010 Kemper Hall, Davis, CA 95616, USA
------------------------------------------------------
Ac ce p
* Corresponding author Tel: +82 42 821 1537; fax: +82 42 821 1593; email: shwoo@hanbat.ac.kr
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
Removal of Reactive Black 5 by zero-valent iron modified with various surfactants
Sudipta Chatterjee1, Seong-Rin. Lim2, and Seung H. Woo1,*
mutagenic. Their release in the environment can cause non-aesthetic pollution, and moreover, azo dyes are not degraded by conventional aerobic wastewater treatment due to their recalcitrance [2]. Thus, effluents containing dye molecules must be treated before their discharge into water bodies to minimize the threat to the environment [3]. Many processes are employed to remove dye molecules from colored effluents, and the treatment methods can be divided into three categories: (i) physical methods such as adsorption [4-6], membrane filtration [7], and ion exchange [8]; (ii) chemical methods such as chemical oxidation [9], electrochemical degradation [10], and ozonation [11]; and (iii) biological degradation [12]. The main disadvantage of physical methods is that
Ac ce p
te
Zero-valent iron (ZVI) particles were synthesized by the aqueous phase
d
M
2
an
Page 2 of 29
us
cr
ip t
44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67
respectively, after 3 h. The color removal efficiency was found to be increased with decrease in initial pH of dye solution, and ZVI exhibited good color removal efficiency at acidic pH. Decolorization kinetics by pseudo-first-order rate equation showed that removal rate was increased after treatment with TX100 as well as CTAB, while that was reduced after SDS treatment.
cr
ip t
68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91
they simply transfer the dye molecules to another phase rather than destroying them, and they are effective only when the effluent volume is small [13]. Chemical methods with high cost are rarely used in the actual treatment process, and the disposal of sludge containing chemicals at the end of treatment requires further use of chemicals [1,3]. Biological degradation processes suffer from low degradation efficiency or even no degradation for some dyes [14].
3
Ac ce p
about 50% of all reactive dyes, and azo dyes are known to be toxic, carcinogenic and
te
d
M
an
Page 3 of 29
us
Keywords: Dye; Reactive Black 5; Reductive degradation; Surfactant; Zero-valent iron
Accepted Manuscript
Title: Removal of Reactive Black 5 by zero-valent iron modified with various surfactants Authors: Sudipta Chatterjee, Seong-Rin. Lim, Seung H. Woo PII: DOI: Reference: To appear in: Received date: Revised date: Accepted date: S1385-8947(10)00171-3 doi:10.1016/j.cej.2010.02.045 CEJ 6821 Chemical Engineering Journal 21-11-2009 19-2-2010 20-2-2010
Sudipta Chatterjee1, Seong-Rin. Lim2, and Seung H. Woo1,*
1
Department of Chemical Engineering, Hanbat National University, San 16-1,
Deokmyeong-dong, Yuseong-gu, Daejeon 305-719, Republic of Korea
1
Department of Chemical Engineering, Hanbat National University, San 16-1,
Deokmyeong-dong, Yuseong-gu, Daejeon 305-719, Republic of Korea
2
Department of Chemical Engineering and Materials Science, University of California,