饮用水消毒副产物的去除途径及进展

饮用水使用氯消毒产生的消毒副产物对人类健康带来了极大危害。本文介绍了饮用水消毒副产物的形成原因及影响因素,并从选择优质水源、降低消毒副产物的前体物质、替换传统的消毒剂、去除已生成的消毒副产物四个方面论述和比较了饮用水中消毒副产物的各种去除途径及进展,指出了在去除消毒副产物方面存在的问题。     

饮用水消毒副产物的去除途径及进展

饮用水使用氯消毒产生的副产物对人类健康带来了极大危害.介绍饮用水消毒副产物的形成原因及影响因素,并从选择优质水源、降低消毒副产物的前体物质、替换传统的消毒剂、去除已生成的消毒副产物4个方面论述了饮用水中消毒副产物的各种去除途径及进展.     

消毒方式及消毒副产物控制研究

主要介绍不同水源采用不同消毒方式控制消毒副产物,不同净水工艺、消毒剂投加量、消毒方式、温度对消毒副产物生成的影响,以及不同消毒剂生成的消毒副产物的研究与控制。     

饮用水消毒副产物的危害及去除途径

介绍了饮用水中消毒副产物的产生及其危害,并从加强水源水保护,采用替代消毒剂和消毒方法,去除消毒副产物的前驱物质、消毒过程中已产生的消毒副产物,制定严格的饮用水水质标准5个方面论述和比较了饮用水中消毒副产物的各种去除途径及进展,并指出了去除副产物过程中存在的问题.     

东太湖水源臭氧-活性炭工艺消毒副产物的生成规律与控制

对以东太湖水为水源的臭氧—活性炭处理工艺和常规处理工艺净水厂的消毒副产物生成情况进行了一年的检测,研究了臭氧—活性炭和常规处理工艺各处理单元对消毒副产物生成势的作用情况。结果表明,臭氧—活性炭和常规处理工艺的出厂水中均含有三卤甲烷、卤乙酸、卤乙腈等消毒副产物;与常规处理工艺相比,臭氧—活性炭处理工艺出水中的消毒副产物种类少、总量低,但三溴甲烷、二溴乙酸的生成量高;臭氧氧化能使消毒副产物生成势提高,砂滤工艺对消毒副产物生成势的去除效果稳定,混凝—沉淀工艺比其他工艺单元对消毒副产物生成势的去除效果好,活性炭工艺在夏季对消毒副产物生成势的处理效果比其他季节好。     

氯胺消毒对卤乙酸类消毒副产物的控制研究

对影响氯胺消毒副产物的因子进行了研究,结果表明:降低氯与氨氮的比值能够降低卤乙酸消毒副产物生成总量,当氯与氨氮比降至5:1时,氯胺消毒产生卤乙酸的总量比氯消毒能够减少69.1%;消毒副产物的生成量与氯胺的投加量呈很好的线性关系;延长接触时间对氯胺消毒副产物的生成量影响小;pH升高能够减少卤乙酸类消毒副产物的生成量;升高温度对卤乙酸生成量的影响很小。采用氯胺取代氯消毒能够很好控制卤乙酸类消毒副产物。     

消毒副产物总致癌风险的首要指标参数--卤乙酸

利用国际和国内饮用水中消毒副产物的一些有代表性的数据 ,计算了各种消毒副产物的致癌风险。分析结果显示 :(1)饮用水中三卤甲烷和卤乙酸浓度的相关性不好 (R2 ≤ 0 4887) ,说明不能从一类消毒副产物的浓度来推断另一类消毒副产物的浓度 ;(2 )在饮用水中消毒副产物的总致癌风险中 ,卤乙酸的致癌风险占 91 9%以上 ,三卤甲烷的致癌风险则在 8 1%以下 ;(3)饮用水中卤乙酸浓度与消毒副产物的总致癌风险之间相关性极好 (R2 ≥ 0 919)。综合以上三点 ,建议将饮用水中卤乙酸浓度作为控制消毒副产物总致癌风险的首要指标参数     

常规工艺中消毒副产物季节变化研究

对某给水厂进行了一个水文年的月度监测,重点分析了各工艺段出水的三卤甲烷和卤乙酸浓度变化。结果表明,对消毒副产物控制起关键作用的工艺是预氯化(混凝)、过滤和消毒。预氯化工艺是一个很大的健康隐患,必须严格控制。在过滤工艺中同时存在消毒副产物的生成和去除两种作用,对三卤甲烷的去除率明显较高,而卤乙酸在过滤前后变化不大。在清水池消毒过程中游离氯会与消毒副产物前体物继续反应生成消毒副产物。     

水中痕量亚硝胺类消毒副产物的分析测试技术

亚硝胺类消毒副产物由于其潜在的高致癌风险正引发国内外水处理领域的极大关注。水中痕量亚硝胺的定量分析测试技术是开展各项研究工作的基础。介绍了水中常见亚硝胺消毒副产物主要单体物质的基本特征;探讨了识别定量分析水中亚硝胺消毒副产物所面临的主要困难和关键问题;从样品的预处理技术和测试技术两个方面论述了目前水中痕量亚硝胺消毒副产物定量分析的主要进展。     

单过硫酸氢钾消毒粉在饮用水消毒中的应用

研究了单过硫酸氢钾消毒粉在模拟常规水处理工艺中的杀菌效果及消毒副产物,并将此消毒剂与现用的液氯消毒效果作比较。结果表明,原水经混凝、沉淀和过滤后,当投加量为0.5mg/L时,单过硫酸氢钾消毒粉可以杀灭水中69%的细菌,细菌总数低于50CFU/mL;在消毒副产物方面,使用低浓度的单过硫酸氢钾消毒粉对信江原水进行消毒时,所产生的三氯甲烷消毒副产物远低于现有的液氯消毒方式。     

常规工艺对消毒副产物及前体物的去除

以西南某市L水厂为测试对象 ,研究了常规水处理工艺过程对消毒副产物及其前体物的去除特性 ,并且提出了控制饮用水中消毒副产物的几点对策。研究结果表明 :常规水处理对三卤甲烷前体物 (THMsFP)和卤乙酸前体物 (HAAsFP)具有很好的去除效果 ,去除率分别为 50 %以上、4 3%～ 6 4 % ,但对卤乙酸和三卤甲烷却无去除作用 ;预氯化是生成出厂水中THMs、HAAs的主要原因。     

Regional variability of disinfection by-products in Canadian drinking water

The chlorination of drinking water forms various disinfection by-products (DBPs), some of which present potential risks to humans. This study investigates occurrences, trends, and regional and seasonal variability of DPBs in two Canadian provinces: Ontario and Quebec. The findings demonstrate that trihalomethanes (THMs) and haloacetic acids (HAAs) can be represented better by region-based analysis than by province-based analysis. THMs in summer months are much higher than in cold months, while HAAs show variable results. The seasonal and regional variability of DBPs can have implications for the selection of DBP sampling locations, sampling frequency, regulatory limitations of DBPs, exposure analysis and risk characterization.     

预臭氧化工艺对消毒副产物影响的生产性研究

通过进行预臭氧化—紫外线联合氯消毒工艺处理高温高藻期滦河水的生产性试验,检测和分析三卤甲烷生成势(THMFP)和卤乙酸生成势(HAAFP)的含量变化情况,研究了整套水处理工艺,尤其是预臭氧化单元对氯消毒副产物(DBPs)的去除效果。同时,研究了甲醛和溴酸盐这两种臭氧化副产物在处理过程中的生成情况。结果表明:在高温高藻期,预臭氧化单元对THMFP和HAAFP的平均去除率分别为12.43%和15.06%,整套工艺对THMFP和HAAFP的平均总去除率分别为39.33%和54.12%,氯消毒副产物前体物得到有效去除;出水中甲醛含量低于50μg/L,溴酸盐的含量小于6μg/L,臭氧氧化副产物得到了有效控制。     

Contribution of brominated organic disinfection by-products to the mutagenicity of drinking water.

The activity inducing chromosomal aberrations of the mixture of brominated disinfection by-products (DBPs) was approximately three times higher than that of the chlorinated counterparts for the same hypohalous acid dose. With the combination of chromosomal aberration test and a new analytical technique to differentiate total organic chlorine (TOCl) and total organic bromine (TOBr), it was found that TOBr was correlated to the mutagenicity of chlorinated waters. It was also implied that for a bromide-to-TOC ratio of 0.1 (mg/mg C), brominated DBPs could account for at least 29% of the total toxicity of DBPs formed during chlorination. On the other hand, bromate ion, a major ozonation DBP, was not a major contributor to the activity inducing chromosomal aberrations of the water treated with an ozone/chlorine sequential process. Therefore, ozonation is one possible option to reduce the health risk caused by DBPs even in the presence of bromide.     

Natural Organic Matter and Disinfection By-products Formation Potential in Water Treatment

The performance of a conventional sequence (pre-ozonation, coagulation/ flocculation/ sedimentation, filtration, disinfection) and two non-conventional sequences (pre-ozonation, nanofiltration; and pre-ozonation, coagulation/ flocculation/ sedimentation, nanofiltration) on the removal of natural organic matter (NOM) and disinfection by-products (DBPs) formation potential was evaluated. Raw and treated waters were characterized in terms of molecular weight, which includes the amount of NOM removed and the qualitative changes in the NOM characteristics (molecular weight and hydrophobicity) since they could be directly related with the DBPs formation. The results demonstrate that, for the type of raw water analysed (hydrophilic with low dissolved organic carbon content, 0.99 L/(mg.m) and 1.31 mg DOC/L), both treatment sequences remove larger molecular weight compounds (>1,900 g/mol). Treated waters have the dominant fractions in the smaller molecular size fractions (<750 g/mol). However, the sequences with nanofiltration have a higher percentage of low molecular weight compounds removed (between 430 and 250 g/mol), when compared with conventional sequence, thus the water from nanofiltration sequences will have lower DBPs formation potential. The removal of the smallest molecular size fractions can be enhanced by optimising the water treatment process and the quality of water will improve relating with DBPs formation.     

Effect of peracetic acid, ultraviolet radiation, nanofiltration-chlorine in the disinfection of a non conventional source of water (Tula Valley).

Water supply for human consumption requires certain quality that reduces health risks to consumers. In this sense, the process of disinfection plays an important role in the elimination of pathogenic microorganisms. Even though chlorination is the most applied process based on its effectiveness and cost, its application is being questioned considering the formation of disinfection by-products (DBPs). Therefore, alternative disinfectants are being evaluated and some treatment processes have been proposed to remove DBPs precursors (organic matter. This paper reports the results of disinfection of a non conventional source of water (aquifer recharged unintentionally with raw wastewater) with peracetic acid (PAA) and ultraviolet radiation (UV) as well as nanofiltration (NF) followed by chlorination to produce safe drinking water. The results showed that a dose of 2 mg/L PAA was needed to eliminate total and faecal coliforms. For UV light, a dose of 12.40 mWs/cm2 reduced total and faecal coliforms below the detection limit. On the other hand, chlorine demand of water before NF was 1.1-1.3 mg/L with a trihalomethane formation potential (THMFP) of 118.62 microg/L, in contrast with chlorination after NF where the demand was 0.5 mg/L and THMFP of 17.64 microg/L. The recommended scheme is nanofiltration + chlorination.