酮连氮法制肼生产中废盐水处理的技术研究

2 0 1 2 年6 月
Thesis Submitted to Hebei University of Technology for The Master of Engineering Degree of Chemical Engineering
STUDY ON TREATMENT TECHNOLOGIES OF WASTEWATER FROM PREPARATION HYDRAZINE HYDRATE BY KETAZINE METHOD
KEY WORDS: high concentration saline wastewater, ammonia wastewater, chemical precipitation, sodium hypochlorite
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河北工业大学硕士学位论文
目录
第一章 文献综述 ...................................................................................................................................... 1
i
酮连氮法制肼生产中废盐水处理的技术研究
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河北工业大学硕士学位论文
STUDY ON TREATMENT TECHNOLOGIES OF WASTEWATER FROM PREPARATION HYDRAZINE HYDRATE BY KETAZINE METHOD
ABSTRACT
The wastewater which produced in the process of preparation hydrazine hydrazine by ketazine process with low concentration of COD, high-salinity and contained hydrazine hydrate,ketazine and other impurities.The normal biochemical method is being limited as a result of the wastewater with high salt characteristics.The direct discharge of the high-salt wastewater not only polluted the ecological environment,but also caused a waste of resources.At present, there is not an effective wastewater treatment method to deal with the wastewater, seriously restricting the development of hydrazine hydrate industry. In this paper, the effective wastewater treatment methods could find through a lot of experiments on the high salt wastewater. Appropriate amount of acetone was added into the wastewater and acetone could react with hydrazine hydrate.Controling acetone:hydrazine(mass ratio) of 40:1 or above,atmospheric distillation and vacuum distillation could improve the conversion of hydrazine hydrate, their highest recovery rate were 60.13% and 85.40% respectively. Secondly, before recycling the wastewater different advanced treatment processes were used to treat the pretreated wastewater under atmospheric distillation. Process one: sodium hypochlorite was regarded as an oxidation to decomposed ammonia nitrogen, hydrazine hydrate and ketazine under the air stripping condition. The effects of reaction temperature, initial pH, NaClO dosage, reaction time on the removal rate of hydrazine hydrate and ammonia nitrogen were investigated respectively.The results showed that:when the NaClO dosage was 2.06% volume of the wastewater, the reaction temperature was 35~40℃, the removal rate of ammonia nitrogen and hydrazine hydrate was 96.3% and above 99% respectively within 30 minutes,COD was reduced from 1650 mg·L-1 to 63.2 mg·L-1, inorganic ammonium was 0.42 mg·L-1 and total ammonium was 2.5 mg·L-1. Process two:So as to recover ammonia nitrogen in the wastewater , two chemicals MgCl2.6H2O and Na2HPO4.12H2O were used to put into wastewater to gencerate magnesium ammonium phosphate(MAP).The effects of initial pH, reaction temperature, Mg：N molar ratio, P ： N molar ratio on the removal rate of ammonia nitrogen were investigated
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酮连氮法制肼生产中废盐水处理的技术研究
respectively.Orthogonal experiment and single optimizing experiment were used to determine optimum process parameters.The ammonia removal efficiency could be achieved to 96.8%,when participangts were MgCl2·6H2O and Na2HPO4·12H2O, pH was 9.0~9.5, n(Mg2+): n(NH4+): n(PO43-) = 1.2:1.0:0.9.Then adding sodium hypochlorite with dosage of 0.80% volume of the wastewater, COD in wastewater could be reduced from 1539 mg·L-1 to 59.8 mg·L-1, inorganic ammonium decreased to 0.27 mg·L-1,total ammonium also decreased to 1.8 mg·L-1 and the removal rate of hydrazine hydrate was above 99%. The wastewater could be used as raw material which reused in chlor alkali production system by the above two different advanced treatment process.
Bห้องสมุดไป่ตู้ Huang Hui
Supervisor: Prof. Li Baichun
June 2012
河北工业大学硕士学位论文
酮连氮法制肼生产中废盐水处理的技术研究 摘 要
酮连氮法制水合肼生产过程中产生的高盐废水，特点是 COD 低、含盐量高、且含有 水合肼及酮连氮等多种杂质，不能用常规生化法处理，直接排放既污染了生态环境，又造 成了资源的浪费。目前国内还没有成熟的工艺来处理该废水，严重制约了水合肼产业的发 展。 本文通过大量的试验研究得到处理该高盐废水的工艺方案。向废水中加入适量丙酮与 废水中的水合肼反应生成酮连氮，控制丙酮∶水合肼（质量比）>40∶1，通过常压精馏和 减压精馏操作可使水合肼的转化率分别高达 60.13%和 85.40%。 其次将常压处理后的高盐废水经两种不同的深度处理工艺路线处理： 工艺一：采用次氯酸钠氧化废水，脱除废水中的氨氮、水合肼、酮连氮等杂质，同时 利用压缩空气进行吹脱。分别考察了反应温度、初始 pH、NaClO 的投加量、反应时间对 水合肼去除率和氨氮去除率的影响。结果表明：NaClO 的投加量为废水体积的 2.06% ， T=35～40℃，反应 30min，氨氮去除率和水合肼去除率分别达到 96.3%和 99%以上，COD 从 1650 mg·L-1 降至 63.2 mg·L-1，无机铵=0.42 mg·L-1，总铵=2.5 mg·L-1。 工艺二：以 MgCl2.6H2O 和 Na2HPO4.12H2O 为沉淀剂使污水中的氨氮以磷酸铵镁 （MAP）的形式沉淀出来。分别考察了 pH、反应温度、Mg：N 摩尔配比、P：N 摩尔配 比对氨氮去除率的影响。采用正交试验方法和单因素优化试验，得出反应的最佳工艺条件 为： 以 MgCl2.6H2O 和 Na2HPO4.12H2O 为沉淀剂， 在 pH=9.0~9.5， n(Mg2+)∶ n(NH4+)∶n(PO43-) = 1.2∶ 1.0∶0.9，NH3-N 去除率为 96.8%。再向废水中投入次氯酸钠溶液，其加入量为废 水体积的 0.80%时，可使废水 COD 从 1539 mg·L-1 降至 59.8 mg·L-1，无机铵=0.27 mg·L-1， 总铵=1.8 mg·L-1，水合肼的去除率达到 99%以上。 废水经上述两个工艺深度处理后可回用于氯碱生产系统所需的原料。 关键词：高盐废水，氨氮废水，化学沉淀，次氯酸钠