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以取自上海市杨树浦水厂的长江原水为研究对象,对比分析了3种常见预氧化剂二氧化氯(ClO2)、高锰酸钾(KMnO4)及氯(Cl2)预氧化对削减氯化和氯胺化消毒副产物(DBPs)生成潜能的效果情况.氯化培养实验结果表明,3种预氧化剂的处理对DBPs总量的去除效果均不显著,经ClO2、Cl2及KMnO4作用后可分别削减8.4%、5.7%及3.9%,效果为ClO2>Cl2>KMnO4.对于长江原水使用氯化消毒时,采用ClO2作为预氧化剂可取得对消毒副产物较好的去除效果.氯胺化培养实验结果表明,3种预氧化剂处理对长江原水氯胺化DBPs的生成潜能影响有较大差异,经ClO2和KMnO4作用后可分别削减18.1%及4.1%,而预氯化后则增高12.3%,对于长江原水使用氯胺化消毒时,采用ClO2作为预氧化剂可取得对消毒副产物较为明显的去除效果.同时,应尽量避免使用预氯化后加氯胺化的组合,以防止在水处理过程中生成更多的DBPs而影响出水水质.  相似文献   
2.
Disinfection by-products (DBPs) in drinking water have caused worldwide concern due to their potential carcinogenic effects. The formation of phenazine from diphenylamine (DPhA) chloramination was studied and its cytotoxicities for two human cancer cells were also investigated. Phenazine was detected synchronously with the consumption of DPhA by chloramination, which further confirmed that the new DBP phenazine can be produced along with N-nitrosodiphenylamine (NDPhA) from DPhA chloramination. The formation of phenazine had a maximum molar yield with solution pH increasing from 5.0 to 9.0, with phenazine as the main product for DPhA chloramination at lower pH, but higher pH favored the formation of NDPhA. Thus, solution pH is the key factor in controlling the formation of phenazine and NDPhA. Both the initial DPhA and chloramine concentrations did not show a significant effect on the molar yields of phenazine, although increasing the chloramine concentration could speed up the reaction rate of DPhA with chloramines. The cytotoxicity assays showed that phenazine had significant cell-specific toxicity towards T24 (bladder cancer cell lines) and HepG2 (hepatic tumor cell lines) cells with IC50 values of 0.50 and 2.04 mmol/L, respectively, and T24 cells being more sensitive to phenazine than HepG2 cells. The IC50 values of phenazine, DPhA, and NDPhA for T24 cells were of the same order of magnitude and the cytotoxicity of phenazine for T24 cells was slightly lower than that of NDPhA (IC50, 0.16 mmol/L), suggesting that phenazine in drinking water may have an adverse effect on human health.  相似文献   
3.
卤化酮(haloketones)具有较强的致癌、致畸和致突变性,是饮用水处理领域颇为关注的一类卤代消毒副产物。这类物质可广泛存在于经消毒后的出厂水中,其含量仅次于三卤甲烷、卤乙酸和卤代腈,浓度一般在ng/L与μg/L的水平。鉴于卤化酮具有较强的致癌、致畸和致突变性,是饮用水处理领域颇为关注的一类卤代消毒副产物,本文对其分类特性、检测方法、生成机理、遗传毒性和致癌性、控制方法等进行了综述,这对于国内开展该方向的研究具有参考价值。  相似文献   
4.
尚晓玲  李咏梅 《环境科学》2012,33(5):1604-1608
为了考察城市污水回用时氯消毒过程中NDMA的形成,以2套生物脱氮实验装置厌氧/缺氧/好氧(A/A/O)和缺氧/好氧(A/O)的二沉池出水为对象,研究了氯胺消毒过程中氯胺剂量、pH、NO2--N和NO3--N浓度对N-亚硝基二甲胺(NDMA)形成的影响.结果表明,二沉池出水中仍然含有微量的NDMA前体物,导致了氯胺消毒过程中NDMA的形成,而且NDMA的浓度会随氯胺浓度的增加呈线性增加;在中性或稍偏碱性(pH 7~8)的条件下,NDMA生成量最大;二沉池出水中NO2--N和NO3--N的浓度对NDMA的含量皆不会产生明显影响.  相似文献   
5.
供水管网中微生物生长和生物膜形成可对管网水质和运行造成重要影响.利用MPN-Griess方法检测了上海某供水系统生物膜中氨氧化细菌的数量,分析了管网中氨氧化细菌与管网水中硝化作用和消毒剂之间的相关性.通过室内实验分析了氨氧化细菌和异养菌对氯胺消毒剂的抗性和消耗影响.结果表明,管网中氨氧化细菌数量(以生物膜干重计)在1.0×102~4.3×105 MPN/g之间,与氨氮、亚硝酸盐氮和硝酸盐氮浓度的相关系数分别为-0.563、 0.603和-0.563;与总氯和一氯胺浓度的相关系数分别是-0.659和-0.571.氨氧化细菌对氯胺消毒剂的抗性明显高于异养菌,对氯胺消毒剂的消耗能力也强于异养菌.  相似文献   
6.
Effects of reaction time, chlorine dosage, pH and temperature on the formation of disinfection byproducts(DBPs), were investigated during the chloramination of Cyclops metabolite solutions. The results showed that some species of DBPs like trichloromethane(TCM), dichloroacetic acid(DCAA) and trichloroacetic acid(TCAA) could accumulate to their respective stable values with a progressive elevation in reaction time and monochloramine concentration. And 1,1,1-2-trichloropropanone(1,1,1-TCP) content decreased correspondingly with a continuous increase of reaction time. The amounts of chloral hydrate(CH), chloropicrin(TCNM), 1,1,1-TCP and DCAA firstly increased and then decreased with increasing monochloramine doses. Higher temperature resulted in a decrease of CH, dichloroacetonitrile(DCAN), 1,1-dichloropropanone(1,1-DCP), 1,1,1-TCP, DCAA and TCAA concentration. pH affected the formation of the different DBPs distinctly. TCM accumulateded with the increase of pH under 9, and DCAA, TCAA, CH and 1,1-DCP decreased continuously with increasing pH from 5 to 10, and other DBPs had the maximum concentrations at pH 6–7.  相似文献   
7.
消毒副产物生成潜能测试常用于表征水中消毒副产物的前体物含量.不同于三氯甲烷等含碳消毒副产物,二卤代乙腈(DHANs)与二卤代乙酰胺(DHAcAms)等含氮消毒副产物在氯消毒的余氯存在下易分解,并且在氯胺消毒过程中可由氯胺提供氮源生成,因此常用于含碳消毒副产物的生成潜能测试方法(如Krasner提出的测试法)可能无法有效揭示DHANs与DHAcAms的前体物水平.本研究以三氯甲烷和氯醛两种含碳消毒副产物为对比,考察DHANs与DHAcAms在饮用水氯消毒与氯胺消毒过程中不同投氯量与反应时间下的生成量,识别最大生成量对应的消毒条件,以便更好地评估水样中DHANs与DHAcAms的前体物浓度.同时,对消毒过程中生成的这些挥发性消毒副产物进行毒性评价.结果显示,两个水样氯消毒的DHANs与DHAcAms生成量分别为6.19~40.08、1.34~15.75 nmol·mg-1(mg-1以TOC计);氯胺消毒的DHANs与DHAcAms生成量分别为2.63~21.46、18.43~49.99 nmol·mg-1.Krasner测试法条件下的DHANs与DHAcAms生成量均最低.在投氯量为TOC+8×NH3-N、反应时间为24 h的氯消毒条件下,氯胺投加量20×TOC、反应时间为3 d的氯胺消毒条件下,两个水样具有最高水平的DHANs与DHAcAms生成量,并且消毒副产物毒性也高于Krasner法测试条件下的毒性水平.因此,氯消毒采用投氯量TOC+8×NH3-N、反应时间24 h,氯胺消毒采用投加量20×TOC、反应时间3 d的生成潜能测试条件可能更好地揭示水中DHANs和DHAcAms的前体物浓度水平.  相似文献   
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