水厂二氧化氯风险评价
二氧化氯气体风险评估报告
CHLORINE DIOXIDE (GAS)This report contains the collective views of an international group of experts and does not necessarily represent the decisions or the stated policy of the United Nations Environment Programme, the International Labour Organization, or the World Health Organization.Concise International Chemical Assessment Document 37First draft prepared by Dr Stuart Dobson, Institute of Terrestrial Ecology, Huntingdon, United Kingdom, and Mr Richard Cary, Health and Safety Executive, Liverpool, United KingdomPublished under the joint sponsorship of the United Nations Environment Programme, the International Labour Organization, and the World Health Organization, and produced within the framework of the Inter-Organization Programme for the Sound Management of Chemicals.World Health OrganizationGeneva, 2002The International Programme on Chemical Safety (IPCS), established in 1980, is a joint venture of the United Nations Environment Programme (UNEP), the International Labour Organization (ILO), and the World Health Organization (WHO). The overall objectives of the IPCS are to establish the scientific basis for assessment of the risk to human health and the environment from exposure to chemicals, through international peer review processes, as a prerequisite for the promotion of chemical safety, and to provide technical assistance in strengthening national capacities for the sound management of chemicals.The Inter-Organization Programme for the Sound Management of Chemicals (IOMC) was established in 1995 by UNEP, ILO, the Food and Agriculture Organization of the United Nations, WHO, the United Nations Industrial Development Organization, the United Nations Institute for Training and Research, and the Organisation for Economic Co-operation and Development (Participating Organizations), following recommendations made by the 1992 UN Conference on Environment and Development to strengthen cooperation and increase coordination in the field of chemical safety. The purpose of the IOMC is to promote coordination of the policies and activities pursued by the Participating Organizations, jointly or separately, to achieve the sound management of chemicals in relation to human health and the environment.WHO Library Cataloguing-in-Publication DataChlorine dioxide (gas).(Concise international chemical assessment document ; 37)1.Chlorine compounds - toxicity2.Oxides - toxicity3.Risk assessment4.Occupational exposure I.International Programme on Chemical SafetyII.SeriesISBN 92 4 153037 5 (NLM Classification: QD 181.C5)ISSN 1020-6167The World Health Organization welcomes requests for permission to reproduce or translate its publications, in part or in full. Applications and enquiries should be addressed to the Office of Publications, World Health Organization, Geneva, Switzerland, which will be glad to provide the latest information on any changes made to the text, plans for new editions, and reprints and translations already available.©World Health Organization 2002Publications of the World Health Organization enjoy copyright protection in accordance with the provisions of Protocol 2 of the Universal Copyright Convention. All rights reserved.The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the Secretariat of the World Health Organization concerning the legal status of any country, territory, city, or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.The mention of specific companies or of certain manufacturers’ products does not imply that they are endorsed or recommended by the World Health Organization in preference to others of a similar nature that are not mentioned. Errors and omissions excepted, the names of proprietary products are distinguished by initial capital letters.The Federal Ministry for the Environment, Nature Conservation and Nuclear Safety, Germany, provided financial support for the printing of this publication.Printed by Wissenschaftliche Verlagsgesellschaft mbH, D-70009 Stuttgart 10TABLE OF CONTENTSFOREWORD1. EXECUTIVE SUMMARY2. IDENTITY AND PHYSICAL/CHEMICAL PROPERTIES3. ANAL YTICAL METHODS3.1 Workplace air monitoring3.2 Biological monitoring in humans4. SOURCES OF HUMAN AND ENVIRONMENTAL EXPOSURE5. ENVIRONMENTAL TRANSPORT, DISTRIBUTION, AND TRANSFORMATION6. ENVIRONMENTAL LEVELS AND HUMAN EXPOSURE6.1 Environmental levels6.2 Occupational exposure7. COMPARATIVE KINETICS AND METABOLISM IN LABORATORY ANIMALS AND HUMANS8. EFFECTS ON LABORATORY MAMMALS AND IN VITRO TEST SYSTEMS8.1 Single exposure8.2 Irritation and sensitization8.3 Short-term exposure8.3.1 Inhalation8.3.2 Oral8.4 Medium-term exposure8.5 Long-term exposure and carcinogenicity8.6 Genotoxicity and related end-points8.6.1 Studies in bacteria8.6.2 In vitro studies in mammalian systems8.6.3 In vivo studies in mammalian systems8.6.4 Studies in germ cells8.6.5 Other studies8.7 Reproductive toxicity8.7.1 Effects on fertility8.7.2 Developmental toxicity8.8 Immunological and neurological effects9. EFFECTS ON HUMANS9.1 Drinking-water studies10. EFFECTS ON OTHER ORGANISMS IN THE LABORATORY AND FIELD11. EFFECTS EV ALUATION11.1 Evaluation of health effects11.1.1 Hazard identification and dose–response assessment11.1.2 Criteria for setting tolerable intakes/concentrations or guidance values for chlorine dioxide gas11.1.3 Sample risk characterization11.2 Evaluation of environmental effects12. PREVIOUS EV ALUA TIONS BY INTERNATIONAL BODIESREFERENCESAPPENDIX 1 — SOURCE DOCUMENTAPPENDIX 2 — CICAD PEER REVIEWAPPENDIX 3 — CICAD FINAL REVIEW BOARDINTERNATIONAL CHEMICAL SAFETY CARDRÉSUMÉ D’ORIENTATIONRESUMEN DE ORIENTACIÓNFOREWORDConcise International Chemical Assessment Documents (CICADs) are the latest in a family of publications from the International Programme on Chemical Safety (IPCS) —a cooperative programme of the World Health Organization (WHO), the International Labour Organization (ILO), and the United Nations Environment Programme (UNEP). CICADs join the Environmental Health Criteria documents (EHCs) as authoritative documents on the risk assessment of chemicals.International Chemical Safety Cards on the relevant chemical(s) are attached at the end of the CICAD, to provide the reader with concise information on the protection of human health and on emergency action. They are produced in a separate peer-reviewed procedure at IPCS. They may be complemented by information from IPCS Poison Information Monographs (PIM), similarly produced separately from the CICAD process.CICADs are concise documents that provide summaries of the relevant scientific information concerning the potential effects of chemicals upon human health and/or the environment. They are based on selected national or regional evaluation documents or on existing EHCs. Before acceptance for publication as CICADs by IPCS, these documents undergo extensive peer review by internationally selected experts to ensure their completeness, accuracy in the way in which the original data are represented, and the validity of the conclusions drawn.The primary objective of CICADs is characterization of hazard and dose–response from exposure to a chemical. CICADs are not a summary of all available data on a particular chemical; rather, they include only that information considered critical for characterization of the risk posed by the chemical. The critical studies are, however, presented in sufficient detail to support the conclusions drawn. For additional information, the reader should consult the identified source documents upon which the CICAD has been based.Risks to human health and the environment will vary considerably depending upon the type and extent of exposure. Responsible authorities are strongly encouraged to characterize risk on the basis of locally measured or predicted exposure scenarios. To assist the reader, examples of exposure estimation and risk characterization are provided in CICADs, whenever possible. These examples cannot be considered as representing all possible exposure situations, but are provided as guidance only. The reader is referred to EHC 1701 for advice on the derivation of health-based guidance values.While every effort is made to ensure that CICADs represent the current status of knowledge, new information is being developed constantly. Unless otherwise stated, CICADs are based on a search of the scientific literature to the date shown in the executive summary. In the event that a reader becomes aware of new information that would change the conclusions drawn in a CICAD, thereader is requested to contact IPCS to inform it of the new information.ProceduresThe flow chart shows the procedures followed to produce a CICAD. These procedures are designed to take advantage of the expertise that exists around the world —expertise that is required to produce the high-quality evaluations of toxicological, exposure, and other data that are necessary for assessing risks to human health and/or the environment. The IPCS Risk Assessment Steering Group advises the Co-ordinator, IPCS, on the selection of chemicals for an IPCS risk assessment, the appropriate form of the document (i.e., EHC or CICAD), and which institution bears the responsibility of the document production, as well as on the type and extent of the international peer review.The first draft is based on an existing national, regional, or international review. Authors of the first draft are usually, but not necessarily, from the institution that developed the original review. A standard outline has been developed to encourage consistency in form. The first draft undergoes primary review by IPCS and one or more experienced authors of criteria documents to ensure that it meets the specified criteria for CICADs.The draft is then sent to an international peer review by scientists known for their particular expertise and by scientists selected from an international roster compiled by IPCS through recommendations from IPCS national Contact Points and from IPCS Participating Institutions. Adequate time is allowed for the selected experts to undertake a thorough review. Authors are required to take reviewers’ comments into account and revise their draft,if necessary. The resulting second draft is submitted to a Final Review Board together with the reviewers’ comments.A consultative group may be necessary to advise on specific issues in the risk assessment document.The CICAD Final Review Board has several important functions:to ensure that each CICAD has been subjected to an appropriate and thorough peer review;to verify that the peer reviewers’ comments have been addressed appropriately;to provide guidance to those responsible for the preparation of CICADs on how to resolve any remaining issues if, in the opinion of the Board, the author has not adequately addressed all comments of the reviewers; andto approve CICADs as international assessments.Board members serve in their personal capacity, not as representatives of any organization, government, or industry. They are selected because of their expertise in human and environmental toxicology or because of their experience in the regulation of chemicals. Boards are chosen according to the range of expertise required for a meeting and the need for balanced geographicrepresentation.Board members, authors, reviewers, consultants, and advisers who participate in the preparation of a CICAD are required to declare any real or potential conflict of interest in relation to the subjects under discussion at any stage of the process. Representatives of nongovernmental organizations may be invited to observe the proceedings of the Final Review Board. Observers may participate in Board discussions only at the invitation of the Chairperson, and they may not participate in the final decision-making process.1. EXECUTIVE SUMMARYThis CICAD on chlorine dioxide gas was based on a review of human health concerns (primarily occupational) prepared by the United Kingdom’s Health and Safety Executive (Health and Safety Executive, 2000). This document focuses on exposures via routes relevant to occupational settings, principally related to the production of chlorine dioxide, but also contains environmental information. The health effects and environmental fate and effects of chlorine dioxide used in the treatment of drinking-water, together with those of halogenated organics produced by the interaction between the disinfectant and other materials present in the water, are covered in a recent Environmental Health Criteria document (IPCS, 2000) and are not dealt with in detail here. Data identified as of September 1998 were covered in the Health and Safety Executive review. A further literature search was performed up to January 1999 to identify any additional information published since this review was completed. Since no source document was available for environmental fate and effects, the primary literature was searched for relevant information. Information on the nature of the peer review and availability of the source document is presented in Appendix 1. Information on the peer review of this CICAD is presented in Appendix 2. This CICAD was approved as an international assessment at a meeting of the Final Review Board, held in Stockholm, Sweden, on 25–28 May 1999. Participants at the Final Review Board meeting are presented in Appendix 3. The International Chemical Safety Card for chlorine dioxide (ICSC 0127), prepared by the International Programme on Chemical Safety (IPCS, 1993), has also been reproduced in this document.Chlorine dioxide (ClO2, CAS No. 10049-04-4) exists as a greenish yellow to orange gas at room temperature. Chlorine dioxide gas is explosive when its concentration in air exceeds 10% v/v. It is water soluble, and solutions are quite stable if kept cool and in the dark. It is marketed and transported as a stabilized aqueous solution, generally less than 1% w/v (more concentrated forms are explosive).Occupational exposure to chlorine dioxide gas may occur during its manufacture, in the paper and pulp bleaching industries, during charging of the aqueous solution into drums, and during its use as a sterilizing agent in hospitals, as a biocide in water treatment, and as an improving agent in flour. During manufacture and subsequent captive use of the gas, good process plant control is essential because of the explosive nature of the gas. Furthermore, once the gas is absorbed in water, it has a low volatility. For these reasons, inhalation exposure is anticipated to be minimal.Limited occupational exposure data are available in relation to the manufacture and uses of chlorine dioxide; the measured or estimated concentrations indicated that all personal airborne exposures (in the United Kingdom) were below 0.1 ppm (0.28 mg/m3) 8-h time-weighted average (TWA) and 0.3 ppm (0.84 mg/m3) 15-min reference period.The most common dermal exposure may arise from contact with aqueous solutions of up to 1% of the substance during preparation and use. It is predicted that dermal exposure from contact with the aqueous solution in occupational settings will range from 0.1 to 5 mg/cm2 per day.Toxicokinetic data are limited, although it would seem unlikely that there would be any significant systemic absorption and distribution of intact chlorine dioxide by dermal or inhalation routes. It is possible that other derivatives, such as chlorate, chlorite, and chloride ions, could be absorbed and widely distributed. One study shows that "chlorine" (chemical form not characterized) derived from aqueous chlorine dioxide is absorbed by the oral route, with a wide distribution and rapid and extensive elimination. No clear information is available on the identity of metabolites, although breakdown products are likely to include, at least initially, chlorites, chlorates, and chloride ions.Given the reactive nature of chlorine dioxide, it seems likely that health effects would be restricted to local responses. There are no quantitative human data, but chlorine dioxide is very toxic by single inhalation exposure in rats. There were no mortalities following exposure to 16 ppm (45 mg/m3) for 4 h, although pulmonary oedema and emphysema were seen in all animals exposed to 16–46 ppm (45–129 mg/m3) chlorine dioxide, the incidence increasing in a dose-related manner. The calculated mean LC50 was 32 ppm (90 mg/m3). In another study, ocular discharge, nosebleeds, pulmonary oedema, and death occurred at 260 ppm (728 mg/m3) for 2 h. Chlorine dioxide is toxic when administered in solution by a single oral dose to rats; at 40 and 80 mg/kg body weight, there were signs of corrosive activity in the stomach and gastrointestinal tract. The calculated oral LD50 was 94 mg/kg body weight.Data on the eye and respiratory tract irritancy of chlorine dioxide gas are limited in extent. However, there is evidence for eye and respiratory tract irritation in humans associated with unknown airborne levels of chlorine dioxide gas. Severe eye and respiratory tract irritancy has been observed in rats exposed to 260 ppm (728 mg/m3) for 2 h.There are no reports of skin sensitization or occupational asthma associated with chlorine dioxide.The quality of the available repeated inhalation exposure data in animals is generally poor, such that the information on dose–response must be viewed with some caution. In addition, there is concern that the nasal tissues were not examined, although rhinorrhoea was reported in one study in rats at 15 ppm (42 mg/m3), indicating that the nasal passages may be a target tissue for inhaled chlorine dioxide. Other rat studies indicated that no adverse effects were reported at 0.1 ppm (0.28 mg/m3) for 5 h/day for 10 weeks or at 1 ppm (2.8 mg/m3) for 2–7 h/day for 2 months. Lung damage, manifested by bronchitis, bronchiolitis, or small areas of haemorrhagic alveolitis, appearsto develop at 2.5 ppm (7.0 mg/m3) or more following repeated exposure for 7 h/day for 1 month and at 10 ppm (28 mg/m3) or more for 15 min twice per day for 4 weeks, with dose-dependent severity. Mortalities occurred following exposure at 15 ppm (42 mg/m3) for 15 min, 2 or 4 times per day, for 1 month. In the same exposure regime, there were no adverse effects reported (among the limited observations performed) at 5 ppm (14 mg/m3).The results of repeated oral exposure studies in rats and primates are generally of limited design and/or quality but show no evidence of systemic toxicity associated with chlorine dioxide administered in the drinking-water or by gavage. There are no data in relation to chronic exposure to or carcinogenicity of chlorine dioxide gas.Studies in mammalian cells using aqueous solutions of chlorine dioxide indicate that chlorine dioxide is an in vitro mutagen. This activity was not expressed in well conducted studies in vivo in somatic or germ cells. However, given the generally reactive nature of this substance and the fact that positive results have been produced in vitro, there is cause for concern for local "site-of-contact" mutagenicity, although no studies have been conducted for this end-point.Oral exposure to chlorine dioxide at parentally toxic levels in rats does not impair fertility or development. This is consistent with the view that as chlorine dioxide is a reactive gas, it would be unlikely to reach the reproductive organs in significant amounts.The available measured occupational exposure data (in the United Kingdom) and the exposure levels predicted using the Estimation and Assessment of Substance Exposure model indicate a maximum likely exposure of 0.1 ppm (0.28 mg/m3), 8-h TWA. Comparison of this exposure level with the no-observed-adverse-effect level (NOAEL), which is derived from very limited data, suggests that there is no cause for concern in relation to the development of irritation of the respiratory tract or of the eyes in workers occupationally exposed to chlorine dioxide.Insufficient data are available with which to conduct an environmental risk assessment. Chlorine dioxide would be degraded rapidly in the environment to yield chlorite and chlorate. The few ecotoxicity data available show that chlorine dioxide can be highly toxic to aquatic organisms; the lowest reported LC50 for fish was 0.02 mg/litre. Chlorate, released in pulp mill wastewaters following use of chlorine dioxide, has been shown to cause major ecological effects on brackish water communities. Brown macroalgae (seaweeds) are particularly sensitive to chlorate following prolonged exposure. The threshold for effects is between 10 and 20 µg/litre.2. IDENTITY AND PHYSICAL/CHEMICAL PROPERTIESChlorine dioxide (ClO2, Chemical Abstracts Service [CAS] No. 10049-04-4), a free radical, exists as a greenish yellow to orange gas at room temperature with a characteristic pungent chlorine-like odour. Chlorine dioxide gas is strongly oxidizing; it is explosive in concentrations in excess of 10% v/v at atmospheric pressure and will easily be detonated by sunlight or heat (Budavari et al., 1996). Its melting point is -59 °C, its boiling point is 11 °C (at 101.3 kPa), and its vapour densityis 2.34 (air = 1).Owing to the difficulties in transportation associated with the explosive nature of aqueous solutions of chlorine dioxide, marketed products are usually stabilized by the addition of substances such as sodium hydrogen carbonate, which leads to the formation of an aqueous sodium chlorite solution rather than chlorine dioxide. However, chlorine dioxide is then generated at the site of intended use by a displacement reaction (such as by the addition of an acid). Its solubility in water is 3 g/litre at 20 °C, and its specific gravity is 1.642 (Budavari et al., 1996).Some of the more commonly used synonyms for chlorine dioxide include chlorine oxide, chlorine peroxide, chloroperoxyl, chlorine(IV) oxide, and chlorine dioxide hydrate.The chemical structure of chlorine dioxide is shown below:·O=Cl=O·The conversion factor for chlorine dioxide in air at 20 °C and 101.3 kPa is 1 ppm = 2.8 mg/m3.Additional physical/chemical properties are presented on the International Chemical Safety Card (ICSC 0127) reproduced in this document.At room temperature and pressure, the natural form of chlorine dioxide is a gas that is unstable, highly reactive (an oxidizing agent), and explosive. Consequently, very few toxicological studies are available that relate to the gaseous form. Some studies have been conducted via the oral route using aqueous solutions of chlorine dioxide. Several of these studies were conducted using "stabilized aqueous chlorine dioxide," sometimes by maintaining a constant pH using sodium carbonate and sodium hydrogen carbonate. However, it is recognized that this would effectively lead to the formation of aqueous sodium chlorite (which can subsequently generate chlorine dioxide by acid displacement). These studies are felt to be less relevant than those using stabilized aqueous chlorine dioxide and are not summarized in this review. The reasons for this are that chlorine dioxide dissolves discretely in water (i.e., it does not dissociate into ions), forming a solution of around pH 5 or less, whereas an aqueous solution of sodium chlorite has a different, ionized composition and a pH of approximately 8. The explosive nature of this substance has limited the concentration of chlorine dioxide in aqueous solutions to a maximum of about 1% w/v.3. ANAL YTICAL METHODS3.1 Workplace air monitoringThe US Occupational Safety and Health Administration (OSHA) has published Method ID 202, "Determination of chlorine dioxide in workplace atmospheres" (Björkholm et al., 1990; OSHA, 1991; Hekmat et al., 1994). This describes a method for making personal exposure measurements of chlorine dioxide. Samples are collected by drawing air through a midget fritted glass bubbler, or impinger, containing 0.02% potassium iodide in a sodium carbonate/sodium bicarbonate buffersolution, at a flow rate of 0.5 litres/min. Chlorine dioxide is trapped and converted to chlorite (ClO2–), which is subsequently measured by suppressed ion chromatography using a conductivity detector. The method has a reported detection limit of 0.004 ppm (0.011 mg/m3) for a 4-h sampling time and 0.06 ppm (0.17 mg/m3) for a 15-min sampling time. However, it is recommended that a sampling time of less than 1 h be used in order to avoid possible negative interference from chlorine and acid gases.3.2 Biological monitoring in humansBecause of the rapid formation of chloride ions following absorption of chlorine dioxide and the high normal, physiological levels of chloride in biological fluids, biological monitoring cannot detect occupational exposure to chlorine dioxide. Hence, there are no published biological monitoring methods available for chlorine dioxide.4. SOURCES OF HUMAN AND ENVIRONMENTAL EXPOSUREThe most significant uses of chlorine dioxide worldwide appear to be in bleaching paper pulp and cellulose. However, owing to the nature of the source document of this CICAD (Health and Safety Executive, 2000), this section focuses mainly on the production of chlorine dioxide.Potential occupational exposure to chlorine dioxide gas may occur during its manufacture, during charging of the aqueous solution into drums, and during its use as a sterilizing agent in hospitals, as a biocide in water treatment, and as an improving agent in flour (Health and Safety Executive, 2000). There will also be potential exposure to aerosol if aqueous solutions of chlorine dioxide are agitated or splashed, such as may occur during the charging of drums. During manufacture and subsequent captive use of the gas, good process plant control is essential because of the explosive nature of the gas. Furthermore, once the gas is absorbed in water, it has a low volatility. For these reasons, inhalation exposure is anticipated to be minimal.Additional uses are reported in bleaching flour, leather, fats and oils, textiles, and beeswax; water purification and taste and odour control of water; cleaning and detanning leather; and manufacture of chlorate salts, oxidizing agents, bactericides, antiseptics, and deodorizers (Budavari et al., 1996). However, no exposure data are available for these uses.It is estimated that up to 1400 tonnes of aqueous chlorine dioxide are used per year in the United Kingdom (Health and Safety Executive, 2000). In North America (USA and Canada), the estimated production in 1980 was 243 000 tonnes per year, and in 1990, it was around 509 000 tonnes per year (Clayton & Clayton, 1994). In Sweden, approximately 75 000 tonnes per year were manufactured (principally in pulp mills) in 1992 (Landner et al., 1995).Release to the environment is almost exclusively to the air. The US Toxic Release Inventory reports total releases of chlorine dioxide in 1996 at approximately 550 tonnes to the atmosphere, of which more than 98% was via stacks and the remainder fugitive air releases. The majority of reported releases were from use of chlorine dioxide in pulp bleaching, with the remainder in foodprocessing.5. ENVIRONMENTAL TRANSPORT, DISTRIBUTION,AND TRANSFORMATIONChlorine dioxide is readily volatilized from aqueous solution at between 10 °C and 15 °C (Budavari et al., 1996). It is quite stable in solution if kept cool, in the dark, and in a closed vessel. Chlorides in solution catalyse decomposition, even in the dark. V olatilized chlorine dioxide decomposes to chlorine and oxygen with noise, heat, flame, and a minor pressure wave at low concentrations; it decomposes explosively at >40 kPa partial pressure.At pHs between 4.8 and 9.8, up to 50% of chlorine dioxide is hydrolysed to chlorite. A chlorite concentration of 0.72 mg/litre was obtained following treatment with chlorine dioxide at 1.5 mg/litre (Moore & Calabrese, 1980).Use of chlorine dioxide in pulp mills leads to the formation of chlorate. This is reduced to chloride in treatment plants, where present (Landner et al., 1995).6. ENVIRONMENTAL LEVELS AND HUMAN EXPOSURE6.1 Environmental levelsNo data are available on levels of chlorine dioxide in the environment. Chlorine dioxide would be degraded in the environment to yield chlorite and chlorate in water, so no water concentrations of chlorine dioxide are expected. However, almost all release is to the atmosphere, with decomposition to chlorine and oxygen.6.2 Occupational exposureThe main source of occupational exposure worldwide would appear to be from the paper and pulp industry. Limited data are available, although one review (Jappinen, 1987) quotes ranges in pulp bleaching of 0–2 ppm (0–5.6 mg/m3) (from Ferris et al., 1967; measured data were from around 1958, although it was not clear if these were from personal monitoring or static samples) and more recent (1965–1972) measurements by the Finnish Institute of Occupational Health of <0.1–2.5 ppm (<0.28–7.0 mg/m3).Limited occupational exposure data were received from one manufacturer of the gas. The data indicated that all personal exposures during drum charging were below 0.1 ppm (0.28 mg/m3) 8-h TWA and 0.3 ppm (0.84 mg/m3) 15-min reference period (Health and Safety Executive, 2000).Limited occupational exposure data were also received from companies using the substance as a biocide in hot and cold water systems and as a sterilizing agent in hospitals. No data were received from firms using it for reducing foul smells and odours in water treatment. During its use as a sterilizing agent in hospitals, all occupational exposures were found to be well below 0.1 ppm。
--二氧化氯专项风险评价评价
－专项评价2－环境风险评估环境风险评估的目的就是通过分析污水处理厂运营期内可能发生的事故类型及其影响程度和范围，以确定开发建设及生产项目什么样的风险是社会可以承受的，从而为工程设计提供参考依据。
污水处理厂具有一定的事故风险性，需要进行必要的环境事故风险分析，提出进一步降低事故风险措施，使得污水处理厂在生产正常运转的基础上，确保污水处理厂内外的环境质量，确保职工及周边影响区内人群生物的健康和生命安全。
1环境风险识别及分析1.1物质危险性识别（1）本项目存在的主要危险、有害的物质本项目存在的主要的危险、有害原料及中间产品的理化性质及毒理性质见表1。
表1 主要危险、有害原料及物质的理化性质及毒理性质（2）危险特性识别本项目存在的风险主要为：①氯酸钠与有机物发生氧化反应放热，引发火灾；强氧化剂氯酸钠遇酸反应产生大量氯，氯酸在40℃以下就会发生爆炸。
②盐酸泄露对周围的物体造成腐蚀或对人员的灼伤。
1.2生产、辅助设备风险性识别结合本项目生产工艺的特点，本项目可能存在风险主要有：①锅炉除尘、脱硫设备发生故障时，对大气造成污染。
②污水核心处理设备发生故障时，对地表水造成的污染。
2环境风险评价等级、评价范围及风险保护目标2.1评价等级结合以上环境风险识别分析，项目所在地位于通辽市边缘，周围居民、企业稀少，所以为非环境敏感区；本项目主要原辅材料基本无毒，储存量没有超过导则规定的贮存场所临界量，因此本项目风险源为非重大风险源。
按照《建设项目环境风险评价技术导则》中的要求，本环境风险评价为二级，见表2。
根据导则要求二级评价可进行风险识别、源项分析和对事故影响进行简要分析，提出防范、减缓和应急措施。
2.2评价范围本项目风险评价等级定为二级评价，根据《环境风险评价技术导则》大气环境风险评价范围为距点源4×6Km2范围内。
地表水风险评价范围为排污口下游30km内，选择CODcr 为预测因子。
和BOD52.3环境风险保护目标根据建设项目所在区域的生态环境（包括：水体、陆域生态特征、社会经济状况、城镇及人口分布、工农业分布。
关于二氧化氯在水厂使用的建议
.关于二氧化氯在水厂使用的建议随着水质标准的提高及水源微污染日益严重，二氧化氯必将替代氯气在水厂大量使用。
二氧化氯在水厂应用后将出现新的问题，为了更好的应用二氧化氯应加强以下几方面的工作。
⒈加强操作人员技术水平。
所以二氧化氯发生器的运行效率取决于操作人员的技术水平。
由于二氧化氯须现场发生，发生器反应条包括原材料性质、发生器原理、应组织操作人员及管理人员进行系统的培训，（厂家没有运行方面的经验尤其用户使用目的各不相同，应编写相应的教件、操作要点等。
）材及制定操作规程。
⒉建立科学规范的管理体系。
根据相应实际不象氯气投加时是简单的物理变化。
由于二氧化氯现场发生是化学变化，发生器原料进料数复配过程的检测监督、情况应建立一套相应管理体系如原料质量的检测、量、发生器反应时间、发生器反应温度、发生器的清洗、计量泵的维护与校定、出口余量的检测标准等管理标准和管理手段。
⒊针对二氧化氯的特点进行工艺改造。
所以在应用时针对其特性相应的进行改造。
由于二氧化氯的化学性质较氯气有很大不同，自身分解等。
预氧化时相应的调整投加例如低浓度杀菌效果突出、遇光分解、遇瀑气溢出、滤后投加二氧化氯应控制在清水池的停留时间缩短工艺流程时间，点多点投加，采取避光、接触时间）等措施。
（保证30min ⒋针对二氧化氯发生器的情况及现场条件进行适应性改造。
二氧化氯发生器的效率是厂家在标准条件下测定出来的，在生产实际工作中应达不到相抓住影响效率的主要因素，实际工作中，应根据发生器的特点及本身实际工作条件，应条件。
进行相应的进行调整、改造，使发生器在高效率状态下运行。
如反应温度、反应时间等，从而提高效率，降低生产成本，提高水质。
5、投加量的限制及注意事项1m投加量不宜超过70%，所以ClO2、由于 1ClO2预氧化时向ClO2ˉ和ClO3ˉ的转化率为，如果超过必须采取副产物去除措施或投加辅助氧化剂以减少二氧化氯投加量。
g/L时，可以引起藻类藻毒素的释放，所以高藻期尽1mg/L 2、由于二氧化氯预氧化投量超过（因复合型的产出物中含有一定量的量不要用二氧化氯预氧化由其复合型二氧化氯发生器。
二氧化氯在水厂的应用
二氧化氯在水厂的应用二氧化氯一、性质：（一）物理性质：①、二氧化氯ClO2摩尔质量为67.453g/mol是在自然界中完全或几乎完全以单体游离原子团整体存在的少数化合物之一。
ClO2熔点-59℃，沸点11℃。
常温下是黄绿色或橘红色气体，ClO2蒸气在外观和味道上酷似氯气，有窒息性臭味，当溶液中ClO2浓度高于30%或空气中大于10%，易发生低水平爆炸，在有机蒸气条件下，这种爆炸可能变得强烈。
②、二氧化氯不稳定、受热或遇光易分解成氧和氯。
③、二氧化氯气体易溶于水，其溶解度约是Cl2的5倍，溶解中形成黄绿色的溶液，具有与Cl2近似的辛辣的刺激性气味。
（二）化学性质：①二氧化氯系一强氧化剂，其有效氯是氯气的2.6倍，与很多物质都能发生强烈反应，二氧化氯腐蚀性很强。
②二氧化氯能与很多无机和有机污染物发生氧化反应其中包括铁、锰、硫化物、氰化物和含氮化物等无机物以及酚类、有机硫化物、多环芳烃、胺类、不饱和化合物、醇醛和碳水化物以及氨基酸和农药等有机物反应。
③、在2-30℃内测定亚硝酸盐和4-甲基酚的阿累尼乌斯图给出了很好的线性关系，每升高1℃其表现速率常数分别增加4%和7%。
二、二氧化氯的消毒机理及特性：二氧化氯对微生物的灭活机理：先进入微生物体内，然后破坏微生物体内的酶和蛋白质以达到灭活微生物的目的，但二氧化氯对细胞壁有较强的吸附和穿透能力，特别是在低浓度时更加突出。
二氧化氯主要通过两种机理灭活微生物，（一）、是二氧化氯与微生物体内的生物分子反应。
（二）、是二氧化氯影响微生物的生理功能。
三、影响二氧化氯消毒效果的因素：1、水温：与液氯消毒相似，温度越高，二氧化氯的杀菌效力越大。
在同等条件下，当体系温度从20℃降到10℃时，二氧化氯对隐孢子虫的灭活效率降低了4%。
温度低时二氧化氯的消毒能力较差，大约5℃时要比20℃时多消毒剂31%～35%。
2、pH值：适应范围宽。
ClO2分解是pH和OH-浓度的函数：当 pH值＞9时2 ClO2+2 OH-= ClO2- + ClO3-+H2O （岐化反应）3、悬浮物：悬浮物能阻碍二氧化氯直接与细菌等微生物的接触，从而不利于二氧化氯对微生物的灭活。
二氧化氯的安全操作及危害范本
二氧化氯的安全操作及危害范本二氧化氯（ClO2）是一种非常强效的氧化剂，它具有强烈的漂白和消毒特性。
在许多工业和消费品中，二氧化氯都被广泛使用。
然而，由于其高度反应性和危险性，使用者必须遵循安全操作指南以确保人员和环境的安全。
本文将介绍二氧化氯的安全操作措施以及其潜在的危害。
首先，使用二氧化氯之前，操作人员必须接受相关的培训和教育，了解该化学物质的特性、危害和安全操作措施。
同时，操作员应穿戴适当的个人防护装备，包括防护眼镜、防护手套和防护服，并确保这些装备不受损坏。
其次，操作人员在处理二氧化氯时必须遵循与该化学物质相关的安全程序和工艺步骤。
这些步骤包括储存、搬运和处理二氧化氯的方法。
例如，二氧化氯应储存在干燥的、通风良好的区域，远离可燃物和易燃物。
当需要搬运二氧化氯时，应使用专门设计的容器，并确保容器安全密封，以防止泄漏。
在处理二氧化氯时，不要直接接触该物质，使用专门的工具和设备进行操作。
另外，二氧化氯在与其他物质发生反应时可能产生有害物质，操作人员必须避免与可燃物、易燃物和氧化剂接触。
此外，需要注意的是，二氧化氯在湿度较高的环境中会与水反应产生毒性的气体，因此应尽量保持操作区域的干燥。
此外，操作人员必须定期检查二氧化氯的储存容器和设备，确保其完整和安全。
任何损坏的容器或设备都应立即报告并进行修复或更换。
在使用二氧化氯时应采取适当的通风措施，确保操作区域良好的空气流动。
如果发生泄漏或溢出，应立即采取紧急措施，如停止泄漏、清除泄漏物和进行适当的清洁。
操作人员应遵循相应的事故应对和紧急处理程序，以减少危害的可能性。
总之，二氧化氯是一种强效的氧化剂，具有潜在的危害性。
为了确保人员和环境的安全，使用者必须遵循安全操作措施和程序。
这些措施包括接受培训、穿戴个人防护装备、遵循安全程序、储存、搬运和处理二氧化氯的方法、避免与其他物质接触、定期检查设备、采取适当的通风措施以及应对泄漏和事故情况。
通过正确使用和操作，可以最大限度地减少二氧化氯可能带来的危害。
自来水厂消毒风险评价的过程与结论
第九章风险评价的过程与结论根据环境风险评价的程序及风险评价中的二级评价要求，结合本项目的特点，技术工作程序包括风险识别、风险评价，提出防范、减缓和应急措施。
9.1、风险识别自来水厂所用的原料液氯属剧毒品，危规号：31001。
氯为黄绿色剧毒气体，有强刺激性臭味；液体相对密度3.214，熔点-100.9℃，沸点-34.6℃，气体相对密度2.49；水溶性（0℃时，在水中溶解度为14.6g/L）；强氧化性，日光下与易燃气体混合时即发生着火爆炸；能与许多化学品如乙炔、松节油、乙醚、氨、燃料气、烃类、氢气、金属粉末等猛烈反应发生爆炸或爆炸性物质，与金属和非金属几乎都能起腐蚀作用；有强刺激和腐蚀性。
中毒机理：氯经呼吸道吸入时，与呼吸道粘膜表面水分接确，首先生成次氯酸和盐酸，次氯酸再分解为盐酸和新生态氧，产生局部刺激和腐蚀作用。
氯气主要作用于支气管和细支气管，也可作用于肺泡，引起支气管痉挛，支气管炎或支气管周围炎，严重者产生中毒性肺水肿。
还可引起迷走神经反射性心跳骤停而出现“闪电型”死亡。
氯气中毒可伴有心肌及其它系统的损害。
氯气对人的急性毒性与空气中氯浓度有关系。
居住区最高充许浓度为0.1mg/m3，车间最高允许浓度为1mg/m3，窒息浓度（30～60min）50PPm，相当于158.5mg/m3；死亡浓度（立即死亡）900PPm，相当于2853mg/m3该厂加氯管采用工业塑料管，除穿越道路时采用管沟或钢管套外，均采用直埋，系统的密闭性好，风险主要出现在氯气库与加氯过程（加氯间）。
根据HJ/T169-2004《建设项目环境风险评价技术导则》附录A中表2有害物质名称及氯的临界量见表9-1。
表9-1 有毒物质名称及临界量该项目拟扩建部份无需增加氯气的储存量，现有工程氯气库可满足扩建后的使用量，现有工程有三组氯瓶(一用二备)，每组5个钢瓶，每瓶1吨氯气）。
对照上表，该氯气库为非重大危险源。
9.2、风险评价9.2.1评价对象项目加氯系流程如下：1t氯瓶→氯源自动切换器→蒸发器→真空加氯机→加氯点水射器→滤后水总渠按最大产生量考虑，本节将对氯气库氯瓶由于设备密闭不严或破裂导致氯气泄露时对周围环境的影响进行分析。
二氧化氯安全评估
二氧化氯安全评估
二氧化氯（ClO2）是一种黄绿色的气体，具有强烈的氯味。
它可用于净化水和空气，具有强大的氧化性和消毒能力。
在使用和储存过程中，需要进行安全评估以确保人员和环境的安全。
首先，对于二氧化氯的使用，应制定严格的操作规程，并对相关人员进行培训，以确保其正确使用和处理。
在使用二氧化氯时，应配备必要的个人防护设备，如呼吸器、防护服和手套等，以防止不慎接触和吸入。
其次，二氧化氯在储存和运输过程中也需要注意安全问题。
二氧化氯通常以压缩气体或液体形式储存，应将其存放在干燥、通风良好的地方，远离热源和易燃物。
在运输过程中，应采取合适的包装和防护措施，防止泄漏和事故发生。
此外，对于二氧化氯的排放要进行严格的管理和控制。
在使用过程中产生的废气和废水应经过适当的处理后排放，以防止对环境造成污染。
在废气和废水处理上，可采用吸附、吸收或氧化等方法，将二氧化氯转化为无害物质。
最后，二氧化氯的安全评估还需要考虑其对人体健康的影响。
二氧化氯在高浓度下具有刺激性，可能导致呼吸道和眼睛等部位的刺激和烧伤。
因此，在使用过程中应确保工作场所通风良好，并定期进行空气质量检测，以及定期体检和健康监测，以确保人员的健康和安全。
综上所述，二氧化氯的安全评估需要对使用、储存、运输、排
放和人体健康等方面进行全面考虑，并采取相应的管理和控制措施，以确保其安全使用和环境健康。
2024年二氧化氯的安全操作及危害(三篇)
2024年二氧化氯的安全操作及危害黄绿色或黄红色气体。
有类似氯气和硝酸的特殊刺激臭味。
液体为红褐色，固体为橙红色。
熔点-59℃。
沸点11℃。
气体密度3.09g/L。
易溶于水，溶于碱溶液、硫酸。
具有强氧化性，其有效氯是氯的2.6倍，与很多物质都能发生剧烈反应。
腐蚀性很强。
二、危险性⒈遇热水则分解成次氯酸、氯气、氧气，受光也分解，其溶液在冷暗处十分稳定。
受热或受光照或遇有机物等能促进氧化作用的物质时，能促进分解并易引起爆炸。
若用空气、二氧化碳、氮气等惰性气体稀释时，爆炸性降低。
⒉具有强烈刺激性。
接触后主要引起眼和呼吸道刺激,引起咳嗽、喷嚏、气急、胸闷以及流涕、流泪等眼、鼻、咽喉部刺激症状及体征。
吸入高浓度可发生肺水肿。
国外曾报告过2例急性中毒，其中死亡1例，空气中本品的浓度低于51mg/m3。
长期接触可导致慢性支气管炎。
皮肤接触高浓度溶液，可引起强烈刺激和腐蚀。
三、主要用途常用的二氧化氯溶液的浓度为8～10g/L，主要用于纸浆和纸、纤维、小麦面粉、淀粉的漂白，油脂、蜂蜡等的精致和漂白，引用水的消毒杀菌处理。
四、安全操作指南⒈包装可用聚氯乙烯桶包装，每桶净重20L或100L。
也可用钢瓶包装。
包装容器的桶身上应加贴化学品安全标签，标签的编写应符合国家标准《化学品安全标签编写规定》（GB15259-xx）。
包装上应明显注明怕热标志。
⒉运输铁路运输时应严格按照铁道部《危险货物运输规则》中的危险货物配装表进行配装。
采用刚瓶运输时必须戴好钢瓶上的安全帽。
钢瓶一般平放，并应将瓶口朝同一方向，不可交叉；高度不得超过车辆的防护栏板，并用三角木垫卡牢，防止滚动。
严禁与易燃物或可燃物、还原剂、食用化学品等混装混运。
夏季应早晚运输，防止日光曝晒。
公路运输时要按规定路线行驶，禁止在居民区和人口稠密区停留。
铁路运输时要禁止溜放。
应使用危险品运输车辆运输。
运输时运输车辆手续证件齐全，符合国家标准或法律法规对安全的要求；运输和押送人员应进行相应的专业技术、安全知识和应急救援的培训，要了解所运载危险品的性质、危害性和发生意外时的应急措施。
液氯泄漏的环境风险评价——以自来水厂为例
环境风险突发性污染事故是指无固定排污方式突然发 液氯泄漏事故的发生具有实际意义。本文以某自来水厂为例，
生难以控制的恶性事故，这种事故具有极大的破坏性和影响 的长期性，并常常造成人员伤亡。建设项目的环境风险评价 是指建 设项目 建设和 运行期 间发生 的可预测 突发性 事故 （一般不包括人为破坏及自然灾害）引起有毒有害物质、 易燃易 爆等物 质泄漏 ，或突 发事件 产生新的 有毒有 害物 质，所造成的对人身安全与环境的影响和损害，进行评估， 提出防范、应急与减缓措施。
注 3：MAC 值来源：工业场所有害因素职业接触限值（GBZ2.1-2007）。
表中 Cl2 的各致死浓度值参照文献[3]的相关内容确定： 当事故发生后，有毒气体造成的致死百分率与有毒气体的 性质、毒气浓度及接触时间有关。通过人们在一定时间接 触一定浓度所造成影响的概率（Y）来表征，Y 与有毒气体 浓度及接触时间的关系由下式计算:
综上所述，本项目生产设施的风险主要来源于储运系 统的液氯泄漏风险。 1.2.3 风险识别结果 1.2.3.1 液氯库。本项目的液氯贮存量小于贮存区临界量， 不构成重大危险源。氯属于有毒物质，液氯钢瓶为风险分
30
2010 年第 6 期（总第 42 期）
环境影响评价
海峡科学
HAI XI A KE XUE
Y = A t + Bt Ln[Cnt e ] 式中：At、Bt、n 为物质系数，取决于毒物的性质；C 为有毒气体浓度；te 为接触时间，本评价取 10min。概率 Y 与致死百分率的关系见文献[3]。
4 风险后果计算与分析
4. 1 预测模式 按最大可信事故源项设定，Cl2 在大气中的扩散采用风
险评价导则中的多烟团模式，对设定事故状态下的 Cl2 在不 利气象条件下（静小风、D 和 F 类稳定度）的浓度分布进 行计算。预测各评价范围内污染物浓度随时间和空间的分 布（详略）。 4. 2 后果计算与分析
二氧化氯在水厂消毒中的应用论文：谈二氧化氯在水厂消毒中的应用
二氧化氯在水厂消毒中的应用论文：谈二氧化氯在水厂消毒中的应用目前，二氧化氯已在欧美数千家水厂得到应用，而我国在这方面起步和发展较慢，从20世纪90年代以后才开始在一些中、小型水厂中加以应用。
从二氧化氯本身的优势以及在解决由水源污染而造成的水质问题上所具的作用来看，二氧化氯在我国饮用水处理中的应用已逐渐引起了人们的重视，二氧化氯作为水厂的常规可选消毒剂在我国的推广也是必然的趋势。
１.二氧化氯与氯气的合理选择1.1二氧化氯与氯气的比较1.1.1二氧化氯所具有的优势①二氧化氯能直接氧化水中的腐殖酸(ha)或黄腐酸(fa)等天然有机物，不与其形成三卤甲烷等氯化物，能大大降低消毒后水中三卤甲烷(thms)等氯消毒副产物。
②二氧化氯在水中不发生水解，不与水中的氨氮反应，因此其杀菌效率不受水中ph值和水中氨氮浓度的影响。
③二氧化氯能有效地氧化去除水中的藻类、酚类及硫化物等有害物质，对这些物质造成水的色、嗅、味等具有比氯气更佳的去除效果。
④二氧化氯能有效杀灭水中用氯消毒效果较差的病毒和孢子等。
1.1.2二氧化氯的不足①消毒成本高。
据资料报道，氯消毒的成本约为0.006元/t，二氧化氯消毒为0.03元/t，两者相差近5倍。
②二氧化氯的检测手段还不完备，分析检测较复杂，相对的操作管理水平也要求较高。
③二氧化氯的过量投加会在水中形成大量的亚氯酸根，对亚氯酸根的毒理学认识，目前仍处于研究阶段。
1.2二氧化氯的最佳使用条件1.2.1受有机物污染的地表水源由于工业污染的加速，地表水源水质不断恶化，再加上有些地表河流的年径流量变化较大，造成枯水期水源中各种有机物、酚类、硫化物的指标严重超标。
例如我国北方某城市，以黄河水为水源，在冬季枯水期用氯消毒时，水厂出水中常含有一种较强的氯酚气味，并且水的口感变差；当采用了二氧化氯进行消毒后，水中气味和口感得到明显改善。
1.2.2藻类、真菌造成的含色、嗅、味的水源对一些以湖泊、水库为水源的水厂，水体富营养化而引起的藻类过量繁殖，以及部分藻类和植物腐烂后所导致的放线菌大量滋生，都会引起水质色度增高并含有异味。
水厂二氧化氯风险评估
环境风险评价1.风险识别1.1风险物质识别根据《危险化学品名录》中的规定，本项目净水工艺过程中涉及到的危险品为液氯。
其可能对人体造成的伤害分析如下：理化性质：黄绿色有刺激性气味的气体。
熔点-101℃，沸点-34.5℃，相对密度( 水=1)1.47 ，相对密度( 空气=1)2.48 。
易溶于水、碱液。
健康危害：对眼、呼吸道粘膜有刺激作用。
急性中毒：轻度者有流泪、咳嗽、咳少量痰、胸闷，出现气管炎的表现；中度中毒发生支气管肺炎或间质性肺水肿，病人除有上述症状的加重外，出现呼吸困难、轻度紫绀等；重者发生肺水肿、昏迷和休克，可出现气胸、纵隔气肿等并发症。
吸入极高浓度的氯气，可引起迷走神经反射性心跳骤停或喉头痉挛而发生“电击样”死亡。
皮肤接触液氯或高浓度氯，在暴露部位可有灼伤或急性皮炎。
慢性影响：长期低浓度接触，可引起慢性支气管炎、支气管哮喘等；可引起职业性痤疮及牙齿酸蚀症。
侵入途径：吸入。
危险标记：6（有毒气体）1.2风险单元的识别在整个加氯过程中大多数设备都是在部分真空下工作的，一般情况不易产生氯气的泄漏。
根据类比调查，氯气泄漏的原因主要是换瓶时操作不当，管道使用时间过长而破损，阀门连接部件垫圈受损及阀门质量不高等引起，其中较为常见的是在换瓶时，由于操作失误引起紫铜管中留有的少量液氯的泄漏。
一般的加氯消毒工艺如图3。
液氯钢瓶液氯管路蒸发器流量计流量计控制阀溶氯器清水池图3加氯消毒工艺流程图3 2.环境风险防范措施2.1操作过程中的安全防范措施为使环境风险减小到最低限度， 必须加强劳动安全卫生管理， 制定完备的安全防范措施，尽可能降低项目环境风险事故发生的概率。
生产操作过程中，必须加强安全管理，提高事故防范措施。
加氯设备必须配备相应的报警系统，配备自动喷水系统等应急预防设施，一旦发生事故性泄漏， 报警系统即会自动报警 (报警浓度为1ppm(0.3158mg/Nm))，并可开启机械通风设备，抽取含氯空气，再经喷淋设备处理后排空。
（水厂）ClO2消毒水质效果影响因素分析及运行风险控制
（水厂）ClO2消毒水质效果影响因素分析及运行风险控制发布时间：2022-04-11T09:33:50.474Z 来源：《中国科技信息》2022年1月上作者：王东包均纲[导读] 为防止通过饮用水传播疾病，在常规水处理中，消毒是必不可少的关键环节。
消毒并非消灭水中全部微生物，只是消除水中致病微生物的致病作用。
水的消毒方法很多，对于传统和普遍的氯消毒方式，由于运行年限较久，系统多项安全指标不能满足新标准要求，运行系统、辅助建构筑物设施、维护管理等多方面出现严重的安全隐患。
为提高生活水水质，以及职工、居民的生活质量，保证人们身体健康，新工艺采用了消毒效果更强，应用较为成熟的ClO2消毒工艺。
中核兰州铀浓缩有限公司王东包均纲甘肃兰州 730065【摘要】：为防止通过饮用水传播疾病，在常规水处理中，消毒是必不可少的关键环节。
消毒并非消灭水中全部微生物，只是消除水中致病微生物的致病作用。
水的消毒方法很多，对于传统和普遍的氯消毒方式，由于运行年限较久，系统多项安全指标不能满足新标准要求，运行系统、辅助建构筑物设施、维护管理等多方面出现严重的安全隐患。
为提高生活水水质，以及职工、居民的生活质量，保证人们身体健康，新工艺采用了消毒效果更强，应用较为成熟的ClO2消毒工艺。
在生产中，用ClO2进行饮用水消毒时，水质会受到多方面因素的影响，消毒效果呈现一定的差异。
经研究，在其他条件（混凝、沉淀、过滤）一定的情况下，水质效果与消毒剂的使用密切相关，其中消毒效果与水中ClO2含量呈正相关关系，在一定范围内，水中ClO2含量的多少直接代表着消毒效果的好坏。
尽管ClO2消毒工艺比之其他消毒工艺有着诸多的优势，但其生产、运行过程存在着一定的安全风险，使用过程中需格外注意。
本文对饮用水ClO2消毒效果影响因素及系统运行风险进行分析，以期为提高饮用水供水水质及管理水平提供参考。
【关键字】：ClO2；消毒效果；影响因素；风险；控制 1.选题的背景和意义二氧化氯作为消毒剂，对细菌的细胞壁有较强的吸附和穿透能力，故ClO2对细菌、病毒等有很强的灭活能力。
二氧化氯区域安全隐患分析与改进
二氧化氯区域安全隐患分析与改进摘要：介绍了二氧化氯区域存在问题，阐述并分析二氧化氯区域存在隐患及产生问题的原因，提出进一步加强对岗位人员现场培训，规范原料进出，及时更新二氧化氯发生器，对计量罐进行更换，解决了现场存在隐患，确保了二氧化氯系统的安全稳定运行。
关键词：二氧化氯盐酸亚氯酸钠隐患对策1、概述水厂供水装置于2006年投用二氧化氯装置，主要目的是对生活水进行消毒，提高生活水水质。
二氧化氯制备技术采用25％的亚氯酸钠水溶液和31％的盐酸进行反应，属于高效生产二氧化氯方法，该方法有二氧化氯纯度高，副产物少等优点，反应原理图见“式1”。
5NaClO2+4HCl 5NaCl+4ClO2+2H2O式1 反应方程式由于该二氧化氯区域盐酸、亚氯酸钠均为危险化学品、生成的二氧化氯也具有强腐蚀性，当水溶液中二氧化氯含量大于30%，会发生爆炸［1］，因此该区域隐患多，问题多对二氧化氯系统的长期稳定运行造成了影响。
2、问题提出2.1 人的不安全因素2.1.1 原料及产品对操作人员的影响由于该反应中采用两种原料，一种为盐酸；另一种为亚氯酸钠，其中盐酸为无色或稍呈黄绿色的透明水溶液，在空气中发烟，具有刺激性气味且有腐蚀性。
亚氯酸钠呈碱性，遇酸易分解放出二氧化氯气体。
亚氯酸钠水溶液仅对许多有机化合物起局部、缓慢的氧化作用。
2.1.2、操作不当对操作人员的影响二氧化氯产品具有强刺激性和一定浓度下爆炸的特性，因此操作人员在操作过程中要严格按照操作规程进行操作，由于盐酸与亚氯酸钠接触后会发生剧烈放热反应，因此首先要避免进错料；其次还要注意盐酸具有较强腐蚀性、挥发性，要避免由于操作不当人员受到伤害、设备设施出现泄漏或爆炸。
2.1.3、易制毒品盐酸属于易制毒品，具有可以作为原料或辅料而制成毒品的性质，因此盐酸的入库情况、管理台账要求完整、清晰，入库量、用量与库存量必须前后对账完整，根据“易制毒化学品管理条例”生成、经营、购买单位记录或者不如实记录交易情况，不按规定保存交易记录或者不如实、不及时向公安机关和有关行政主管部门备案销售情况的，对违反规定生产单位，由负有监督管理职责的行政主管部门给予警告、责令限期改正，并处罚款等措施，因此要求加强对盐酸规范管理。
二氧化氯在水厂应用中存在问题分析
二氧化氯在水厂应用中存在问题分析王丽张光明(深圳市水质检测中心清华大学深圳研究生院)摘要:不同纯度的二氧化氯C102用于水厂消毒，其生成的三氯甲烷量以及Ames试验结果是不同的，较高纯度的C102才可有效控制三氯甲烷量和Ames试验结果阴性。
在C102消毒的水厂中普遍检测出C102消毒的无机副产物亚氯酸盐C102ˉ。
C102去除藻类效果较好，但有可能增加藻毒素的风险。
关键词：二氧化氯C102，三氯甲烷，亚氯酸盐C102ˉ,藻长期以来，简便而又经济的氯消毒是世界上绝大多数水厂所采用的消毒方法，然而自1974年发现饮水氯消毒产生三卤甲烷类物质以后，对饮水消毒的安全研究越来越深入。
二氧化氯C102由于与水中的氯化前驱物反应不生成三卤甲烷类物质而成为氯的较好替代消毒剂，己经逐渐在一些小水厂得到应用，深圳市现在一些小水厂使用CIO2采用的是氯酸盐法现场发生产生CIO2。
大量研究表明，C102能够有效杀灭水中的细菌、病毒、藻类以及浮游生物等有害微生物，对水中的Fe2+, Mn2+, S2–, C Nˉ以及酚类和胺类等无机和有机污染物均有良好的去除效果。
同其它消毒剂相比，C102具有自己独特的优点，但在其消毒过程中的化学和生物安全性问题也值得关注。
1 C I 02应用中的纯度问题1.1不同纯度的C102对三级甲烷生成的影响C102的发生方法主要有两种一化学法和电解法，其中化学法发生C102的技术相对成熟，电解法发生CIO2技术正在发展中。
化学法发生C102分为亚氯酸钠法和氯酸钠法。
由于C102发生方法和发生技术的不同，产生的CIO2纯度也不尽相同，即在C102气体中含有浓度不同的CI2。
表1为C102和CI2混合液与氯化前驱物间苯三酚、间苯二酚反应生成三氯甲烷CHC13的试验结果。
由表1可见，C102和CI2混合液与间苯三酚、间苯二酚反应，随着CIO2在混合消毒剂中所占比例的增加，CHC13生成量才有较大幅度的降低，但C102含量在70%以前，CHC13生成量降低十分明显，C102含量达90%时CHC13可达98%去除率，即基本控制了CHC13生成。
供水管网中氯化消毒副产物健康风险评价
供水管网中氯化消毒副产物健康风险评价陈梦杰;张凤娥;董良飞;李源;张建兵【摘要】为了评价南方某城市供水管网中氯化消毒副产物对人体健康产生的潜在危害,对该市全线供水管网中的三卤甲烷和卤乙酸质量浓度进行检测,并采用美国环境保护署(US EPA)的健康风险评价方法,对管网水体中氯消毒副产物通过食入、皮肤接触和呼吸吸入3种途径进入人体的危害进行了风险计算和初步评价.结果表明:管网水体中消毒副产物对人体健康产生的致癌风险最大值为4.32×10-5,在美国环境保护署(US EPA)可以接受的限值(10-6～10-4)内,不会对人体产生明显的健康危害.【期刊名称】《常州大学学报（自然科学版）》【年(卷),期】2016(028)002【总页数】5页(P46-49,87)【关键词】供水管网;消毒副产物;健康风险评价【作者】陈梦杰;张凤娥;董良飞;李源;张建兵【作者单位】常州大学环境与安全工程学院,江苏常州213164;常州大学环境与安全工程学院,江苏常州213164;常州大学环境与安全工程学院,江苏常州213164;常州大学环境与安全工程学院,江苏常州213164;常州通用自来水有限公司,江苏常州213003【正文语种】中文【中图分类】X820.4三卤甲烷(THMs)和卤乙酸(HAAs)是饮用水氯化消毒的典型副产物，供水管网中THMs和HAAs浓度过高，将会对人体健康造成危害。
为了解该市生活饮用水水质的卫生状况和氯化消毒副产物(DBPs)的健康风险，课题组对该市全线供水管网水中的THMs中的三氯甲烷(TCM)、一溴二氯甲烷(DBCM)、二溴一氯甲烷(BDCM)、三溴甲烷(TBM)和HAAs中的二氯乙酸(DCAA)的含量进行了检测，并根据美国环境署的评价方法进行初步健康风险评价，以期为全面提高和保障饮用水水质安全性提供依据和对策。
1.1 采样点和采样时间布置采样点：以该市输水与供水主干线为研究对象，考虑到管网中水体流动的复杂性，从源头到供水管网末梢依次布置监测点，全面调查分析输配水管网、二次加压过程中水质的变化以及管网末梢水质情况。
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3.0 环境风险评价3.1 风险识别3.1.1风险物质识别根据《危险化学品名录》中的规定，本项目净水工艺过程中涉及到的危险品为液氯。
其可能对人体造成的伤害分析如下：理化性质：黄绿色有刺激性气味的气体。
熔点-101℃，沸点-34.5℃，相对密度(水=1)1.47，相对密度(空气=1)2.48。
易溶于水、碱液。
健康危害：对眼、呼吸道粘膜有刺激作用。
急性中毒：轻度者有流泪、咳嗽、咳少量痰、胸闷，出现气管炎的表现；中度中毒发生支气管肺炎或间质性肺水肿，病人除有上述症状的加重外，出现呼吸困难、轻度紫绀等；重者发生肺水肿、昏迷和休克，可出现气胸、纵隔气肿等并发症。
吸入极高浓度的氯气，可引起迷走神经反射性心跳骤停或喉头痉挛而发生“电击样”死亡。
皮肤接触液氯或高浓度氯，在暴露部位可有灼伤或急性皮炎。
慢性影响：长期低浓度接触，可引起慢性支气管炎、支气管哮喘等；可引起职业性痤疮及牙齿酸蚀症。
侵入途径：吸入。
危险标记：6（有毒气体）3.1.2 风险单元的识别在整个加氯过程中大多数设备都是在部分真空下工作的，一般情况不易产生氯气的泄漏。
根据类比调查，氯气泄漏的原因主要是换瓶时操作不当，管道使用时间过长而破损，阀门连接部件垫圈受损及阀门质量不高等引起，其中较为常见的是在换瓶时，由于操作失误引起紫铜管中留有的少量液氯的泄漏。
一般的加氯消毒工艺如图3。
3.2环境风险防范措施3.2.1 操作过程中的安全防范措施为使环境风险减小到最低限度，必须加强劳动安全卫生管理，制定完备的安全防范措施，尽可能降低项目环境风险事故发生的概率。
生产操作过程中，必须加强安全管理，提高事故防范措施。
加氯设备必须配备相应的报警系统，配备自动喷水系统等应急预防设施，一旦发生事故性泄漏，报警系统即会自动报警(报警浓度为1ppm(0.3158mg/Nm3))，并可开启机械通风设备，抽取含氯空气，再经喷淋设备处理后排空。
自动喷水池的废水需进行单独处理，经中和处理，沉淀后排放。
在厂区四周种植一些常绿高大抗性树种，形成绿色屏障。
3.2.2事故应急措施①泄露：迅速撤离泄漏污染区人员至上风处，并立即进行隔离，小泄漏时隔离150米，大泄漏时隔离450米，严格限制出入。
建议应急处理人员戴自给正压式呼吸器，穿防毒服。
尽可能切断泄漏源。
合理通风，加速扩散。
喷雾状水稀释、溶解。
构筑围堤或挖坑收容产生的大量废水。
如有可能，用管道将泄漏物导至还原剂(酸式硫酸钠或酸式碳酸钠)溶液。
也可以将漏气钢瓶浸入石灰乳液中。
漏气容器要妥善处理，修复、检验后再用。
废弃物处置方法：建议把废气通入过量的还原性溶液中(亚硫酸氢盐、亚铁盐、硫代亚硫酸钠溶液)，中和后用水冲支下水道。
废水中的氯气和氯化铝电解中氯气回收。
②消防：本品不燃。
消防人员必须佩戴过滤式防毒面具(全面罩)或隔离式呼吸器、穿全身防火防毒服，在上风处灭火。
切断气源。
喷水冷却容器，可能的话将容器从火场移至空旷处。
灭火剂：雾状水、泡沫、干粉。
③急救：皮肤接触：立即脱去被污染的衣着，用大量清水冲洗。
就医。
眼睛接触：提起眼睑，用流动清水或生理盐水冲洗。
吸入：迅速脱离现场至空气新鲜处。
呼吸心跳停止时，立即进行人工呼吸和胸外心脏按压术。
就医。
④防护措施呼吸系统防护：空气中浓度超标时，建议佩戴空气呼吸器或氧气呼吸器。
紧急事态抢救或撤离时，必须佩戴氧气呼吸器。
眼睛防护：呼吸系统防护中已作防护。
身体防护：穿带面罩式胶布防毒衣。
手防护：戴橡胶手套。
其它：工作现场禁止吸烟、进食和饮水。
工作毕，淋浴更衣。
保持良好的卫生习惯。
进入罐、限制性空间或其它高浓度区作业，须有人监护。
3.3 环境风险突发事故应急预案根据本环境风险分析的结果，对于本项目可能造成环境风险的突发性事故制定应急预案纲要，见表10，供项目决策人参考。
表10 环境风险突发事故应急预案1 适用范围本导则规定了工业园区突发环境事件应急预案（以下简称应急预案）编制的基本要求，使工业园区能够依据法律、法规和其他相关要求，在强化园区风险管理，有效降低突发环境事件发生概率的前提下，建立健全园区环境应急管理体系，规定环境应急响应措施，对突发环境事件作出有序响应，及时组织有效救援，最大限度减少事件造成的损失。
本导则适用于江苏省内涉及环境风险源的工业园区，包括：分布有向环境排放污染物的单位，生产、贮存、经营、使用、运输危险物质的单位以及产生、收集、贮存、利用、处置危险废物等单位的工业园区。
本导则不适用于分布有存在生物安全事故和辐射安全事故风险单位的工业园区。
2 园区环境应急救援的方针、原则环境应急救援必须坚持“安全第一、预防为主、全员动手、综合治理、改善环境、保护健康、科学管理、持续发展”的方针，体现以人为本、求实求严的思想，切实加强应急管理，以最快的速度、最大的效能有序地实施救援，最大限度减少人员伤亡、财产损失和对外环境的影响，把事件危害降到最低，维护园区内外企业（或事业）单位及周边居民的安全和稳定。
组织实施环境应急救援活动的基本原则为：集中管理、统一指挥、规范运行、标准操作、快速反应、救援高效。
3 规范性引用文件《国家突发公共事件总体应急预案》；《国家突发环境事件应急预案》；《江苏省突发公共事件总体应急预案》；《危险物质名录》（国家安全生产监督管理局公告2003第1号）；《剧毒化学品名录》（国家安全生产监督管理局等8部门公告2003第2号）；《国家危险废物名录》；《危险废物鉴别标准腐蚀性鉴别》（GB 5085.1）《危险废物鉴别标准急性毒性初筛》（GB 5085.2）《危险废物鉴别标准浸出毒性鉴别》（GB 5085.3）《危险废物鉴别标准易燃性鉴别》（GB 5085.4）《危险废物鉴别标准反应性鉴别》（GB 5085.5）《危险废物鉴别标准毒性物质含量鉴别》（GB 5085.6）《危险废物鉴别标准通则》（GB 5085.7）《危险废物鉴别技术规范》（HJ/T 298）《重大危险源辨识》（GB 18218）；《建设项目环境风险评价技术导则》（HJ/T 169）；《建设项目环境影响评价分类管理名录》；《地表水环境质量标准》（GB 3838）《地下水质量标准》（GB/T 14848）《环境空气质量标准》（GB 3095）；《大气污染物综合排放标准》（GB 16297）；《污水综合排放标准》（GB 8978）；《恶臭污染物排放标准》（GB 14554）；《工业企业设计卫生标准》（GBZ1）；《工作场所有害因素职业接触限值》（GBZ2）；其他相关的法律、法规、规章和标准。
以上凡不注明日期的引用文件，其有效版本适用于本导则。
4 术语和定义下列术语和定义适用于本导则。
4.1 危险物质指《危险化学品名录》和《剧毒化学品名录》中的物质和易燃易爆物品。
4.2 危险废物指列入《国家危险废物名录》或者根据危险废物鉴别标准和危险废物鉴别技术规范（HJ/T298）认定的具有危险特性的固体废物。
4.3 环境风险源指可能导致突发环境事件的污染源，以及生产、贮存、经营、使用、运输危险物质或产生、收集、利用、处置危险废物的场所、设备和装置。
4.4 环境敏感区根据《建设项目环境影响评价分类管理名录》规定，指依法设立的各级各类自然、文化保护地，以及对建设项目的某类污染因子或者生态影响因子特别敏感的区域。
4.5 环境保护目标指在突发环境事件应急中，需要保护的环境敏感区域中可能受到影响的对象。
4.6 环境事件指由于违反环境保护法律法规的经济、社会活动与行为，以及由于意外因素的影响或不可抗拒的自然灾害等原因致使环境受到污染，生态系统受到干扰，人体健康受到危害，社会财富受到损失，造成不良社会影响的事件。
4.7 次生衍生事件某一突发公共事件所派生或者因处置不当而引发的环境事件。
4.8 突发环境事件指突然发生，造成或者可能造成重大人员伤亡、重大财产损失和对全国或者某一地区的经济社会稳定、政治安定构成重大威胁和损害，有重大社会影响的涉及公共安全的环境事件。
4.9 应急救援指突发环境事件发生时，采取的消除、减少事件危害和防止事件恶化，最大限度降低事件损失的措施。
4.10 应急监测指在环境应急情况下，为发现和查明环境污染情况和污染范围而进行的环境监测，包括定点监测和动态监测。
4.11 恢复指在突发环境事件的影响得到初步控制后，为使生产、生活和生态环境尽快恢复到正常状态而采取的措施或行动。
4.12 应急预案指根据对可能发生的环境事件的类别、危害程度的预测，而制定的突发环境事件应急救援方案。
要充分考虑现有物质、人员及环境风险源的具体条件，能及时、有效地统筹指导突发环境事件应急救援行动。
4.13 分类指根据突发环境事件的发生过程、性质和机理，对不同环境事件划分的类别。
4.14 分级分级指按照突发环境事件严重性、紧急程度及危害程度，对不同环境事件划分的级别。
4.15 应急演练为检验应急预案的有效性、应急准备的完善性、应急响应能力的适应性和应急人员的协同性而进行的一种模拟应急响应的实践活动。
根据所涉及的内容和范围的不同，可分为单项演练、综合演练和指挥中心、现场应急组织联合进行的联合演练。
5 应急预案编制程序5.1 成立预案编制小组针对园区可能发生的主要环境事件类别，结合本园区内部职能分工，成立以园区主要负责人为领导的应急预案编制工作组，明确预案编制任务、职责分工和工作计划。
预案编制人员应由具备应急指挥、环境评估、环境生态恢复、生产过程控制、安全、组织管理、医疗急救、监测、消防、工程抢险、防化、环境风险评估等各方面专业的人员及专家组成。
5.2 基本情况调查与环境风险分析5.2.1 工业园区的基本情况。