Bacteria inactivation by sulfate radical: progress and non-negligible disinfection by-products

● Status of inactivation of pathogenic microorganisms by SO₄^•− is reviewed. ● Mechanism of SO₄^•− disinfection is outlined. ● Possible generation of DBPs during disinfection using SO₄^•− is discussed. ● Possible problems and challenges of using SO₄^•− for disinfection are presented. Sulfate radicals have been increasingly used for the pathogen inactivation due to their strong redox ability and high selectivity for electron-rich species in the last decade. The application of sulfate radicals in water disinfection has become a very promising technology. However, there is currently a lack of reviews of sulfate radicals inactivated pathogenic microorganisms. At the same time, less attention has been paid to disinfection by-products produced by the use of sulfate radicals to inactivate microorganisms. This paper begins with a brief overview of sulfate radicals’ properties. Then, the progress in water disinfection by sulfate radicals is summarized. The mechanism and inactivation kinetics of inactivating microorganisms are briefly described. After that, the disinfection by-products produced by reactions of sulfate radicals with chlorine, bromine, iodide ions and organic halogens in water are also discussed. In response to these possible challenges, this article concludes with some specific solutions and future research directions.     

污水氯和二氧化氯消毒过程中溶解性有机物变化的三维荧光光谱解析

采用三维荧光光谱（3DEEM）技术对污水在氯和二氧化氯消毒过程中溶解性有机物（DOM）的变化进行了初步解析.结果表明,与饮用水、地表水等不同,生物处理出水含有较多的芳香族蛋白质和溶解性微生物代谢产物,且其中的腐殖质主要为生物源,芳香性较弱.在氯和二氧化氯消毒后,污水DOM中的芳香族蛋白质和微生物代谢产物类物质的荧光峰发生蓝移,即峰值的激发或发射波长减少了几个nm,这可能由芳香环结构的破坏引起;而腐殖质类物质的荧光峰发生红移,即峰值的激发或发射波长增加了几个到二十几个nm,此现象与地表水相反,可能与腐殖质的来源不同有关.与遗传毒性的变化类似,氨氮对水样氯消毒后的荧光变化有明显影响,但对二氧化氯消毒后的荧光变化无明显影响.     

O3、UV、H2O2及其组合工艺处理有机污染物的效果对比研究

采用O3、UV(紫外光)、H2O2及其多种组合工艺处理乙酸有机污水,在不同的操作条件下进行比较和探讨,结果表明:组合工艺较之单独氧化剂具有优势,其对乙酸的去除能力为O3/H2O2相似文献   

基于贝叶斯网络的给水管网消毒副产物生成因素分析

给水管网消毒副产物(disinfection byproducts,DBPs)的生成受管网环境因素、微生物群落特征和水厂未完全去除的有机物等多指标共同影响.各指标间相互关联形成复杂的网络结构,导致影响DBPs在管网内生成的主控因子较难确定.以广州某高校给水管网系统为研究对象,于2021年1～2月开展终端水质调查,利用吹...     

新型含氮消毒副产物的生成机制及毒性研究进展

含氮消毒副产物(N-DBPs)具有很高的生物毒性和致癌性,近年来受到广泛关注。本文对目前N-DBPs的研究进展进行了概述,重点总结了典型N-DBPs包括卤乙腈(HANs)、卤代硝基甲烷(HNMs)、卤代乙酰胺(HAcAms)和亚硝胺(NAs)的生成机制;并归纳了N-DBPs的毒性效应和毒性机制。根据N-DBPs的生成途径,应该重点控制水中含胺类氮源前体物,并优化设计消毒剂种类和投加方式,在控制病原体的前提下,尽量削减高毒性N-DBPs的生成。本研究旨在为控制消毒副产物生成、提高饮用水水质提供理论参考。     

Bacterial inactivation,DNA damage,and faster ATP degradation induced by ultraviolet disinfection

• Long amplicon is more effective to test DNA damage induced by UV. • ATP in bacteria does not degrade instantly but does eventually after UV exposure. • After medium pressure UV exposure, ATP degraded faster. The efficacy of ultraviolet (UV) disinfection has been validated in numerous studies by using culture-based methods. However, the discovery of viable but non-culturable bacteria has necessitated the investigation of UV disinfection based on bacterial viability parameters. We used quantitative polymerase chain reaction (qPCR) to investigate DNA damage and evaluated adenosine triphosphate (ATP) to indicate bacterial viability. The results of qPCR effectively showed the DNA damage induced by UV when using longer gene amplicons, in that sufficiently long amplicons of both 16S and gadA indicated that the UV induced DNA damages. The copy concentrations of the long amplicons of 16S and gadA decreased by 2.38 log/mL and 1.88 log/mL, respectively, after exposure to 40 mJ/cm² low-pressure UV. After UV exposure, the ATP level in the bacteria did not decrease instantly. Instead it decreased gradually at a rate that was positively related to the UV fluence. For low-pressure UV, this rate of decrease was slow, but for medium pressure UV, this rate of decrease was relatively high when the UV fluence reached 40 mJ/cm². At the same UV fluence, the ATP level in the bacteria decreased at a faster rate after exposure to medium-pressure UV.     

富锌金针菇菌株的诱变选育及酶谱分析

以金针菇F19为出发株,通过制备菌丝断片悬液和紫外线照射(3—14min)来筛选突变株。结果发现,12min处理使菌丝体生物量减少了5.14%(p>0.05),但富锌量提高了18.78%(p<0.01);在连续3代的遗传稳定性实验中,菌丝体生物量为1.342—1.419g/100ml,富锌量为49.78—50.45mg/g,与原代差异均不显著(p>0.05)。PAGE技术测定发现,EST是金针菇遗传分析最适标记之一;高锌通过提高EST、POD的合成和活性来促进有机锌的转化和菌丝体的生长。     

二沉池出水的电化学消毒试验研究

对德国威斯巴登城市污水处理厂和上海石化股份公司水质净化厂二沉池出水分别进行了电化学消毒试验。试验结果表明,用电化学方法对威斯巴登城市污水处理厂和上海石化股份公司水质净化厂二沉池出水进行消毒是可行的,消毒效果好,耗电少,杀菌率随电流、处理时间的增加而提高。     

蛋白酶对水环境中病毒的灭活作用

以大肠杆菌噬菌体T₄作为模式病毒,研究了蛋白酶对病毒的灭活作用.试验结果表明:蛋白酶灭活病毒的效果明显. 适宜条件下,67.5u/mL的蛋白酶K处理1h对纯水中病毒(6.2×10⁵PFU/L)和生活污水中病毒(7.2×10⁵PFU/L)灭活率分别达到了99.4%和49.4%,处理3h的灭活率分别是>99.9%和81.1%;工业蛋白酶1398在75.0u/mL酶浓度下处理1h对纯水水中病毒(1.7×10⁵ PFU/L)灭活率达到74.4%.pH和温度对病毒灭活效果的影响不明显.     

垃圾填埋场渗滤液处理工艺研究

通过对垃圾填埋处理场渗滤液的处理工艺研究,并根据渗滤液的特性建立一套适合我国实际的 Ａ— Ｏ— Ｃ— Ｃ Ｌ 处理工艺．试验研究结果表明,出水ρ（ Ｃ Ｏ Ｄ Ｃｒ） ＝ ２０５ ．６ ｍｇ Ｌ－ １ 、ρ（ Ｂ Ｏ Ｄ５） ＝ １８ ．２ ｍｇ Ｌ－ １ 、ρ（ Ｎ Ｈ３ － Ｎ） ≈０ｍｇ Ｌ－ １ 、色度＝ ４０（ 倍） 、ｎ（ 大肠菌群数） ＝ ２００ 个 Ｌ－ １ ．达到 Ｇ Ｂ１６８８９ － １９９７《生活垃圾填埋污染控制标准》中对垃圾渗滤液排放要求的二级标准