二氧化氯对颤蚓的灭活效果及机理初步探讨

Chlorine dioxide inactivation effect of Tubifex tubifex and preliminary investigation of inactivation mechanism

供水系统中蠕虫类水生生物的出现严重危及供水水质安全.为实现供水系统中蠕虫风险的高效控制,以颤蚓为研究对象,探讨了二氧化氯对颤蚓的灭活动力学及水质对灭活效果的影响,并对灭活机理进行了初步探讨.结果表明:CT值(氧化剂浓度和接触时间的乘积)可以较好地用于评价ClO_2对颤蚓的灭活效果;灭活过程符合伪一级延迟Chick-Watson模型.温度的升高缩短了颤蚓灭活时的"延滞期",并提高了灭活效率;实验条件下,体系pH的增加有助于提高ClO_2灭活效率;浊度和有机物浓度的增加会导致灭活效率显著降低.当CT值超过80 mg·min·L^(-1)后,ClO_2将导致体系蛋白质浓度显著降低.颤蚓灭活过程中"延滞期"的出现和蛋白试验结果综合表明:颤蚓表皮层的存在有助于提高其对ClO_2的耐受性.SOD(超氧化物歧化酶)活性变化表明,ClO_2灭活颤蚓的主要作用机理之一是含氧自由基的诱导效应.

Aquatic organisms such as invertebrate worms in water supply system result in serious pollution of drinking water quality. In order to achieve the efficient control of worms risk in water supply system, the inactivation kinetics of chlorine dioxide on worms as well as the effect of water quality on the inactivation were studied by taking T. tubifex as the object worm. In addition, the inactivation mechanism was preliminarily investigated. The results showed that the CT value （ the product of C102 concentration and contact time） could be used to evaluate the inactivation effect of C102 on T. tubifex, and the inactivation process was found to comply with a delayed pseudo first-order Chick-Watson expression. The increasing temperature reduced the lag period of 7＂. tubifex inactivation thus raised the inactivation efficiency. Under the tested conditions, the increase of pH value in the system could improve the inactivation efficiency, whereas the increase of turbidity and CODMn could significantly reduce the efficiency. When the CT value exceeded 80 mg-min＂ L-i , it resulted in notable decline of protein concentration. Both the occurrence of lag period during T. tubifex inactivation and the protein tests showed that the presence of T. tubifex epidermis could contribute to its tolerance to C102. The variation of SOD （Superoxidc Disnutase） activity also indicated that the induction effect of the oxygenic free radical is one of the main mechanisms in the inactivation of T. tubifex by chlorine dioxide.