含菌水氯消毒过程中内毒素浓度和赋存状态的变化特征  

Variation Characteristics of Endotoxin Concentration and Its Occurrence During Chlorine Disinfection of Bacteria Contaminated Water

作　　者：孙慕涵 张崇淼[1,2] 汤雁麟 董雨雨 于卫华 SUN Muhan;ZHANG Chongmiao;TANG Yanlin;DONG Yuyu;YU Weihua(School of Environmental and Municipal Engineering,Xi′an University of Architecture and Technology,Xi′an 710055,China;Key Laboratory of Northwest Water Resource,Environmental and Ecology,Ministry of Education,Xi′an University of Architecture and Technology,Xi′an 710055,China;School of Military Preventive Medicine,Air Force Medical University,Xi′an 710032,China)

机构地区：[1]西安建筑科技大学环境与市政工程学院,陕西西安710055 [2]西安建筑科技大学,西北水资源与环境生态教育部重点实验室,陕西西安710055 [3]空军军医大学军事预防医学系军事毒理学教研室,陕西西安710032

出　　处：《环境科学研究》2024年第8期1760-1768,共9页Research of Environmental Sciences

基　　金：国家自然科学基金项目(No.32171231)。

摘　　要：污水中细菌释放的内毒素对人体健康构成潜在威胁,为阐明污水氯消毒过程中内毒素浓度和赋存状态的变化特征,利用1、2、5、10 mg/L NaClO溶液对含有大肠杆菌的水样进行消毒实验,分别使用鲎试剂动态显色法和Zeta电位仪测定氯消毒过程中水样内毒素浓度、赋存状态及粒径的动态变化,研究有效氯浓度和接触时间对含菌水样内毒素生成的影响。结果表明:①含菌水样经氯消毒后,其内毒素释放呈现出典型的二级动力学特征。随着有效氯浓度增加和消毒时间延长,水中内毒素浓度逐渐增加。氯消毒30 min后水中内毒素浓度可达1517.3 EU/mL,相较于消毒前增长近12倍。如果保持CT(有效氯浓度×接触时间)值恒定,采用较高有效氯浓度与较短接触时间的组合方式会生成较多内毒素。②随着氯消毒时间延长,水中的结合态内毒素逐渐转变为游离态内毒素。不同剂量氯消毒30 min后,水中游离态内毒素在总内毒素中的占比为73.3%~94.1%。③随着有效氯浓度升高,内毒素生成速率加快,平均粒径逐渐增加。在氯消毒过程中,水中游离态内毒素粒径约为160~310 nm。高浓度有效氯消毒能促进游离态内毒素的聚集,水中游离态内毒素浓度与粒径呈显著正相关。研究显示,氯消毒条件对水中内毒素浓度和赋存状态都有显著影响,采用较低有效氯浓度的氯消毒有助于减少内毒素释放,可为污水氯消毒过程中的内毒素风险防控提供科学依据。The endotoxin released by bacteria in wastewater poses a potential threat to human health.In order to elucidate the variation characteristics of endotoxin concentration and its occurrence during chlorine disinfection of wastewater,experiments were conducted to disinfect water samples containing Escherichia coli using NaClO solutions with concentrations of 1,2,5 and 10 mg/L.The dynamic changes in endotoxin concentration,occurrence state and particle size in water samples during chlorine disinfection were measured using limulus amebocyte lysate assay and Zeta potentiometer,respectively.The effects of available chlorine concentration and contact time on the endotoxin production in bacteria contaminated water samples were studied.The results showed that:(1)After chlorine disinfection,the release of endotoxins in bacteria contaminated water samples exhibited typical second-order kinetic characteristic.With the increase of available chlorine disinfection and the extension of disinfection time,the endotoxin concentration in water gradually increased.After 30 min of chlorination,the endotoxin concentration in water reached 1517.3 EU/mL,which was 12 times higher than that before disinfection.If the CT(available chlorine concentration×contact time)value was constant,a combination of higher available chlorine concentration and shorter contact time would produce more endotoxins.(2)As chlorination time prolonged,the bound endotoxins in the water gradually transformed into free endotoxins.After 30 min chlorination at different doses,the proportion of free endotoxins in the total endotoxin reached 73.3%-94.1%.(3)With the increase of available chlorine concentration,the production rate of endotoxin accelerated,and the average particle size gradually increased.During the chlorine disinfection,the particle size of the free endotoxins in water was approximately 160-310 nm.Chlorine disinfection with high concentration of available chlorine could promote the aggregation of free endotoxins,and a significant positive correlation exist

关 键 词：氯消毒 大肠杆菌 游离态内毒素 结合态内毒素 粒径 

分 类 号：X703[环境科学与工程—环境工程]