饮用水中氯消毒的应用及存在的主要问题

氯消毒在饮用水净化过程中被广泛采用,我国99.5%以上的水厂用氯消毒,在美国也有94.5%的自来水厂用氯消毒。氯消毒一般采用预加氯和后加氯两种方式。氯在消毒的同时会产生三卤甲烷、二氯乙酸等消毒副产物。这些消毒副产物有致癌、致畸、致突变性和遗传毒性,对人体的健康存在一定的危害性。在氯消毒过程中,余氯量越多产生的消毒副产物就越多,而余氯量过少对病毒的灭活性较差,同时在输水管中细菌就会大量繁殖,加快管道的腐蚀。不同浓度的余氯排入水体还会对鱼类和水生生物造成不同程度的毒性影响。     

饮用水含氮消毒副产物NDMA控制技术研究进展

N-亚硝基二甲胺（NDMA）作为一种新发现的饮用水消毒副产物,由于其具有高致癌风险,已逐渐成为水环境化学研究领域的一个热点。本文介绍了饮用水含氮消毒副产物NDMA的相关背景,分析了光降解、生物降解、臭氧氧化、高级氧化技术、吸附法、反渗透膜法及金属催化等各种NDMA去除工艺,探讨了各种工艺的特点以及对NDMA的去除性能。     

含氮有机污染物在环境介质中的迁移转化及影响因素分析

水环境中含氮有机污染物(Nitrogenous Organic Pollutants,NOPs)的存在,可导致消毒过程中产生致癌性和致突变性的含氮消毒副产物(N-DBPs),对饮用水安全构成严重威胁。介绍在饮用水处理过程中可能生成N-DBPs的几类NOPs,分析了它们在水环境中的分布特征、迁移转化规律及影响因素。在综述现有成果基础上,对该领域今后研究方向进行了展望。     

沱江枯水期内江段集中式供水的致突变性研究

本文以Ames试验检测了以沱江为水源的内江市东兴水厂枯水期原水和新、旧两两种工艺处理的出厂水的有机浓集物的致突变性,并对两种工艺去除三卤甲烷前体物的能力进行了比较。研究结果表明:在本试验条件下,其原水未检出致突变性;两种处理工艺的出厂水均能检出较弱的致突变性;新工艺能更有效地去除原水中的三卤甲烷前体物。     

用紫露草微核技术监测饮用水

随着科学的发展,人们不仅关心饮用水的一般水质问题,而且对其慢性的潜在性影响也极为重视。众所周知,饮用水在加氯消毒处理的过程中,游离余氯与水中有机物反应生成的三卤甲烷对人体健康具有潜在危害,有些国家为此还制定了自来     

饮用水预氯化工艺潜在的健康风险及改进工艺的研究进展

本文分析了预氯化技术对饮用水安全性的影响,以及提高饮用水的安全性和改进常规预处理工艺的研究进展.预氯化因会增加消毒副产物的生成,其作用不断受到质疑.预臭氧氧化、预高锰酸钾氧化和预氯胺氧化工艺等都在不同程度上对消毒副产物生成起到抑制作用,逐步被用于强化常规工艺.     

食品、大气和水中含有的致畸致癌物

关于环境中致畸致癌物的研究是在分子水平上探索化学物质对人类健康的毒性的一门新的科学。其研究对象是对 DNA(去氧核糖核酸)分子的损伤、细胞的突变,并且评价对人类的毒性。而且,最近的许多研究成果表明:致突变与致癌关系十分密切,引起突变往往是致癌的先导,许多诱变物质也就是致癌物质。因此这个领域的研究活动已成为现代最引人注目的热门。特别是最近几年的进展令人惊异。     

粉末活性炭在饮用水处理中应用的研究进展

介绍了粉末活性炭（PAC）的基本性质，并对其在饮用水处理应用中的重要影响因素进行了探讨；综述了PAC去除原水中嗅味物质、藻毒素、消毒副产物前驱物以及农药等痕量有机污染物的研究现状；分析了粉末活性炭（PAC）与其他工艺的组合技术在饮用水处理中的应用效果，并对其应用前景做出展望。     

气相色谱法同时测定地表水中丙酮和丁酮

采用吹扫捕集—气相色谱法测定地表水中丙酮和丁酮,并对吹扫捕集的条件进行优化。实验结果表明,该方法具有灵敏度高、定量准确、操作简便等特点,丙酮的检出限为0.08μg/L,丁酮的检出限为0.10μg/L,适合于地表水和生活饮用水中丙酮和丁酮的测定。     

要重视有毒有害化学品的环境管理

作者在文章中指出:现代工业的飞速发展使化学品越来越多地进入人类环境,虽然其中污染环境和危害生物的只占少数,但这些有毒有害化学品对人类及自然环境的毒害和破坏却是显而易见的。有毒有害化学品对人体和生物有致死、致畸、致癌、致突变和干扰生物行为等作用,按其毒性作用又可分为急性毒性和慢性毒性。     

Water quality in a non-traditional off-stream polyethylene-lined reservoir

Annual water storage in a 5.3 ha, polyethylene-lined, off-stream irrigation reservoir in northern Alabama, USA, resulted in marked improvement in water quality. Results of three-year monitoring from June 1999 to May 2002 indicate that the relatively static conditions of the reservoir enhanced settling of suspended particles by 85% (from 14.4 to 2.1 mg TSS/L) that cleared the water and increased sunlight penetration. The organic and inorganic particles that settled to the bottom removed up to 88% of the nutrients and other chemical substances from the water. Nutrients remaining in the water column were rapidly assimilated by phytoplankton algae. With the basin sealed at the bottom and no runoff input there was limited opportunity for nutrients or other substances to enter the reservoir in quantities that would adversely affect water quality. Consequently, reservoir water was found to be of high quality and suitable as a raw water supply. Non-traditional, off-stream storage reservoirs such as described in this paper may be uniquely suited for agricultural irrigation and public water supply in regions such as southeastern US that experience relatively frequent drought conditions but have relatively abundant long-term annual rainfall.     

厌氧-准好氧型填埋的渗滤液实验研究

通过室内模拟试验，在渗滤液回灌的厌氧填埋柱基本进入稳定状态后，改用准好氧运行方式。同时监测了渗滤液中有机物浓度以压温度、pH值的变化。改变模拟垃圾柱的运行方式两个月以后。氨氯浓度由2000mg／L迅速下降至101．48mg／L，试验结果显示，准好氧运行方式可以解决生物反应器填埋场进入稳定阶段后存在的氨氮浓度高的问题，加速填埋场的稳定。     

微山湖养殖湖区水体中多环芳烃的分布及来源

采用HPLC定量分析微山湖养殖湖区水体中16种优先控制PAHs的总量浓度范围在5348.8～12970.8ng/L之间,平均值为8671.5ng/L,处于中等偏高污染水平;养殖湖区水体中的多环芳烃主要来源于养殖船只的石油泄露及煤炭、木材与石油的不完全燃烧,PAHs的组成以2～3环为主。     

农村水源地水质重金属健康风险评估研究

介绍了饮用水水源地中基因毒物质和躯体毒物质所致的健康危害的风险度计算模型,并根据雅安市雨城区农村水源地水质实测资料,进行健康风险评价与分析。结果表明:(1)基因毒物质由饮水途径所致健康危害的个人年风险按大小排列为Cr(VI)>As>Cd,而躯体毒物质的个人年风险按大小排列为Hg>Pb>Mn>Fe,但前者的影响远大于后者;(2)水源地中的3种基因毒物质所致健康危害的个人年风险,远远超过瑞典环保局、荷兰建设和环境部推荐的最大可接受水平1.00×10-6a-1,且Cr(VI)的健康风险危害超过国际辐射防护委员会(ICRP)推荐的最大可接受值5.00×10-5a-1,应将Cr(VI)视为本区饮水的优先治理污染物。     

污泥土地利用中重金属铜污染地下水的潜在风险研究

本研究旨在通过土柱淋溶实验来研究堆肥污泥土地利用后重金属铜的溶出性,以及对地下水的影响。结果表明:与去离子水相比,模拟酸雨(pH=4.5)会使土壤中Cu的淋溶强度增加,并更能促使其向下迁移。经长期淋溶后发现,淋出液中铜的浓度呈现有起伏的递减趋势,最高峰浓度达到0.0702mg/L,远低于地下水Ⅲ类标准(1.0mg/L),污泥土地利用后Cu对地下水的污染风险较小。     

Photodegradation of selected herbicides in various natural waters and soils under environmental conditions

The photochemical degradation of herbicides belonging to different chemical groups has been investigated in different types of natural waters (ground, river, lake, marine) and distilled water as well as in soils with different texture and composition. Studied herbicides and chemical groups included atrazine, propazine, and prometryne (s-triazines); propachlor and propanil (acetanilides); and molinate (thiocarbamate). The degradation kinetics were monitored under natural conditions of sunlight and temperature. Photodegradation experiments were performed in May through July 1998 at low concentrations in water samples (2-10 mg/L) and soil samples (5-20 mg/kg), which are close to usual field dosage. The photodegradation rates of all studied herbicides in different natural waters followed a pseudo-first order kinetics. The half-lives of the selected herbicides varied from 26 to 73 calendar days in waters and from 12 to 40 d in soil surfaces, showing that the degradation process depends on the constitution of the irradiated media. The presence of humic substances in the lake, river, and marine water samples reduces degradation rates in comparison with the distilled and ground water. On the contrary, the degradation in soil is accelerated as the percentage of organic matter increases. Generally, the photodegradation process in soil is faster than in water. The major photodegradation products identified by using gas chromatography-mass spectrometry (GC-MS) techniques were the hydroxy and dealkylated derivatives for s-triazines, the dechlorinated and hydroxy derivative for the anilides, and the keto-derivative for the thiocarbamate, indicating a similar mode of degradation for each chemical category.     

WATER QUALITY IN SHALLOW ALLUVIAL AQUIFERS,UPPER COLORADO RIVER BASIN,COLORADO, 19971

ABSTRACT: Shallow ground water in areas of increasing urban development within the Upper Colorado River Basin was sampled for inorganic and organic constituents to characterize water‐quality conditions and to identify potential anthropogenic effects resulting from development. In 1997, 25 shallow monitoring wells were installed and sampled in five areas of urban development in Eagle, Grand, Gunnison, and Summit Counties, Colorado. The results of this study indicate that the shallow ground water in the study area is suitable for most uses. Nonparametric statistical methods showed that constituents and parameters measured in the shallow wells were often significantly different between the five developing urban areas. Radon concentrations exceeded the proposed USEPA maximum contaminant level at all sites. The presence of nutrients, pesticides, and volatile organic compounds indicate anthropogenic activities are affecting the shallow ground‐water quality in the study area. Nitrate as N concentrations greater than 2.0 mg/L were observed in ground water recharged between the 1980s and 1990s. Low concentrations of methylene blue active substances were detected at a few sites. Total coliform bacteria were detected at ten sites; however, E. coli was not detected. Continued monitoring is needed to assess the effects of increasing urban development on the shallow ground‐water quality in the study area.     

Veterinary drugs in groundwater in a dairy region of central Argentina and risk assessment for human health

Veterinary drugs used in dairy production are potential contaminants of surface or groundwater sources, being able to affect human and environmental health. It is known that chronic exposure to antibiotics in low concentrations present in water can generate microbial resistance. This study aimed to evaluate the presence of veterinary drugs in 53 groundwater samples used for animal and human consumption, collected in dairy milking parlors, in an important milk-producing area of central Argentina, and to assess the risk to human health when they are used as drinking water. In 75% of the total samples analyzed, at least one veterinary drug was detected. The most frequently found drugs in water samples were the antibiotics tetracycline in 58.5% and oxytetracycline in 56.6%, and an anti-inflammatory, flunixin in 39.6%. In the water samples, the tetracycline and oxytetracycline concentrations were between 0.1 and 5.3 μg/L and flunixin concentrations were between 0.01 and 2.1 μg/L. The frequency of appearance and the concentration levels of the substances found in the water samples were evaluated according to the productivity, size, and production system (confined or pasture) of the dairy farms. Higher concentrations and proportions of water samples containing antibiotics were observed when the number of animals per dairy farm was >182 and when the productivity was high (>25 liters per animal per day). In the case of flunixin, the percentage of detection was similar in all evaluated categories. The risk assessment for children and adults, considering the intake of drinking water containing residues of these drugs, did not indicate a significant health risk. It would be advisable to evaluate other sources of drinking water, both surface and underground, in other regions of the country, to provide data to assess the impact of these substances and the other contaminants on environmental and human health.     

生物氧化法处理高浓度含氨、含氰废水

通过对用普通活性污泥法法处理高浓度含氨、含氰废水的可行性分析,总结了装置改进后,在工艺流程;微生物的培养及驯化;运行参数的选择等方面的运行情况。提出适宜的浓度范围是: NH3—N<500 mg/l;COD<800 mg/L;氰化物<10 mg/L;镍<10 mg/L。结论为:① 用生物氧化法处理高浓度含氨、含氰废水,不仅可行,而且处理效果比较好;② 该装置的水质适应性比较好,对低浓度的毒性物质有降解作用,如氰化物、镍等;③ 此工艺产生的污泥量比较少。     

电絮凝＋电氧化法处理山西某区块煤层气采出水研究与实践

山西省某区块煤层气采出水水质均值为COD 170 mg/L,BOD₅29.7 mg/L,氨氮5.36 mg/L,氟化物6.59 mg/L,4个污染物指标超过GB 3838—2002《地表水环境质量标准》Ⅳ类水质限值要求。文章针对该地区煤层气采出水的可生化性差(BOD₅/COD≤20%)、氯离子含量较高等特点,采用“电絮凝+电氧化”法进行中试试验,处理后水质COD≤17 mg/L,氨氮≤0.1 mg/L,氟化物≤1.0 mg/L,试验结果表明:采用该方法可以有效降低COD、氨氮、氟化物等主要污染物指标,使该区块煤层气采出水达到GB 3838—2002标准Ⅳ类水质要求(COD≤30 mg/L、氨氮≤1 mg/L、氟化物≤1 mg/L)。应用中试试验研究成果,采用“双电+保障(过滤)”工艺在该区块建成了煤层气采出水处理示范工程,水处理站建成投运后出水水质稳定,始终满足GB 3838—2002《地表水环境质量标准》Ⅳ类水质要求。