Indian Institute of Technology, Roorkee, Roorkee, Uttrakhand, 247667, India.
Environ Sci Pollut Res Int. 2017 Dec;24(34):26269-26278. doi: 10.1007/s11356-017-0568-z. Epub 2017 Nov 3.
Apart from numerous other well-known drawbacks of chlorination, viz. on-site operational hazards and residual chlorine toxicity, trihalomethane (THM) formation is the major factor that came into limelight in the last 40 years, primarily in drinking water treatment industry. Treated effluent from wastewater treatment plants is also chlorinated and then discharged, indirectly coming in human contact, so there is need to consider THM as a potable as well as wastewater parameter. In this study, THMs were identified in seven sewage treatment plants (STPs) in North India. STPs were selected based on treatment technology employed, viz., up-flow anaerobic sludge blanket (UASB), activated sludge process (ASP), sequential batch reactor (SBR), and oxidation pond (OP). THM concentrations obtained at all the seven STPs were below BIS standards of drinking water (0-40 μg L). UASB plant shows considerably higher concentration of THM. UV followed by chlorination is suggested as an alternative to chlorination. Per million liter per day (MLD) capital and operation and maintenance (O&M) costs of UV disinfection were analyzed revealing decreasing per MLD capital cost of UV with increasing plant capacity. The comparative annual O&M cost analysis of chlorination, dechlorination, and UV disinfection shows that there is up to 63% reduction of the total annual O&M cost by UV in comparison to chlorination, whereas in the case of chlorination followed by dechlorination, total reduction is 71%.
除了氯消毒的许多其他众所周知的缺点，如现场操作危险和余氯毒性外，三卤甲烷 (THM) 的形成是过去 40 年来的主要因素，主要在饮用水处理行业。污水处理厂的处理后的废水也经过氯化然后排放，间接与人接触，因此需要将 THM 视为饮用水和废水参数。在这项研究中，在印度北部的七个污水处理厂 (STP) 中鉴定出了三卤甲烷。根据所采用的处理技术选择 STP，即上流式厌氧污泥床 (UASB)、活性污泥法 (ASP)、序批式反应器 (SBR) 和氧化塘 (OP)。在所有七个 STP 中获得的三卤甲烷浓度均低于 BIS 饮用水标准（0-40μg/L）。UASB 工厂显示出相当高的三卤甲烷浓度。建议使用紫外线代替氯化作为替代氯化的方法。分析了每天每百万升 (MLD) 的资本和运营与维护 (O&M) 成本，结果表明随着工厂容量的增加，紫外线消毒的每 MLD 资本成本呈下降趋势。氯化、脱氯和紫外线消毒的年度运营和维护成本分析表明，与氯化相比，紫外线可将总年度运营和维护成本降低高达 63%，而在氯化后进行脱氯的情况下，总减少量为 71%。
