生物膜慢滤-消毒对二级出水中条件致病菌的去除效能  

Removal efficiency of opportunistic pathogens in secondary effluent by biofilm slow filtration and disinfection

作　　者：孙丽华[1] 郗梓瑄 刘烨辉 张钼晞 SUN Li-hua;XI Zi-xuan;LIU Ye-hui;ZHANG Mu-xi(Key Laboratory of Urban Rainwater System and Water Environment Ministry of Education,Beijing University of Civil Engineering and Architecture,Beijing 100044,China;School of Environmental and Energy Engineering,Beijing University of Civil Engineering and Architecture,Beijing 100044,China;Beijing Municipal Commission of Transport Mentougou Highway Branch,Beijing 102300,China)

机构地区：[1]北京建筑大学城市雨水系统与水环境教育部重点实验室,北京100044 [2]北京建筑大学环境与能源工程学院,北京100044 [3]北京市交通委员会门头沟公路分局,北京102300

出　　处：《安全与环境学报》2023年第4期1241-1249,共9页Journal of Safety and Environment

基　　金：国家自然科学基金(52070011)。

摘　　要：再生水回用是解决水资源危机的重要途径。但是城市污水厂二级出水中仍含有大量条件致病菌,潜在威胁着人类的身体健康。本文以生物膜慢滤-消毒作为深度处理工艺,探究该工艺对条件致病菌(军团菌、铜绿假单胞菌)与大肠杆菌的去除效能及机制。结果表明:相同滤速下,生物膜慢滤较慢滤对条件致病菌的去除效果好;滤速越小对条件致病菌的去除效果越好,最佳滤速为5 cm/h,此时生物膜慢滤对二级出水中军团菌、铜绿假单胞菌、大肠杆菌的去除率分别为92.9%、94.0%、65.7%;慢滤与生物膜慢滤对颗粒黏附态条件致病菌的去除效果优于自由悬浮态条件致病菌,对颗粒黏附态条件致病菌的去除率均在90%以上。在最佳滤速下,对生物膜慢滤出水用次氯酸钠(NaClO)和紫外(UV)进行消毒,根据投加消毒剂后水中的条件致病菌含量,确定NaClO最佳投加质量浓度为8.0 mg/L(以有效氯质量浓度计),UV的最佳辐射强度为40 mJ/cm^(2);紫外消毒较次氯酸钠消毒对慢滤出水中条件致病菌的去除效果更佳。在生物膜中存在假单胞菌属、嗜酸菌属、鞘氨醇单胞菌属与乳酸菌属,这些菌属均对条件致病菌的生长起到一定的抑制作用。NaClO消毒主要通过水解生成的次氯酸完成对慢滤出水中条件致病菌的灭活,而UV消毒主要通过光化学反应氧化以完成对条件致病菌的灭活。综上,生物膜慢滤-消毒工艺可有效去除二级出水中的条件致病菌,保证再生水回用的微生物安全性。Reuse of reclaimed water is an important way to solve the water crisis,but secondary effluent from municipal wastewater plants still contains a large number of opportunistic pathogens that potentially threaten human health.In this study,biofilm slow filtration-disinfection was used as an advanced treatment process to investigate the removal efficiency and mechanism of opportunistic pathogens(Legionella and Pseudomonas aeruginosa)and E.coli.The results show that at the same filtration rate,the biofilm slow filtration is more effective than slow filtration in the removal of opportunistic pathogens.The lower the filtration rate,the better the removal of opportunistic pathogens,and the best filtration rate is 5 cm/h.At this time,the removal rates of Legionella,Pseudomonas aeruginosa,and E.coli in the secondary effluent of biofilm slow filtration are 92.9%,94.0%,and 65.7%,respectively.Slow filtration and biofilm slow filtration are more effective in removing opportunistic pathogens in a particle adhesion state than in a free suspension state.The removal rate of conditionally pathogenic bacteria in particle adherence was above 90%.Based on the optimal filtration rate,the biofilm slow filtration water was disinfected with sodium hypochlorite(NaClO)and ultraviolet(UV),and the optimal dosage of NaClO was determined to be 8.0 mg/L(in terms of effective chlorine mass concentration),and the optimal dosage of UV was determined to be 40 mJ/cm^(2);UV disinfection is better than sodium hypochlorite disinfection in removing opportunistic pathogens in slow filtration water.There are Pseudomonas,Acidophilus,Sphingomonas,and Lactobacillus genera in the membrane,which all played a certain role in inhibitory the growth of opportunistic pathogens;NaClO disinfection was mainly accomplished by hydrolysis of hypochlorite(HClO)to inactivate opportunistic pathogens in the slow filtration effluent,while UV disinfection was mainly accomplished by oxidation through a photochemical reaction.In summary,the biofilm slow filtration-disinfection pr

关 键 词：环境工程学 深度处理 再生水 条件致病菌 生物膜慢滤 次氯酸钠 紫外 

分 类 号：X703[环境科学与工程—环境工程]