净水厂水蚤类浮游动物的生物风险及影响因素研究

Biosafety Risk and Influencing Factors of Daphnia Zooplankton in Waterworks

针对净水厂水蚤类浮游动物带来的感官问题及潜在的生物安全风险,考察了净水厂沉淀池出水中水蚤类浮游动物死体溶出物的微生物含量和有机物浓度、超声时间和频率对水蚤类浮游动物的影响,以及不同预氧化剂投加量和排泥周期时对水蚤类浮游动物的控制效果。结果表明,净水厂沉淀池出水中水蚤类浮游动物体内携带细菌,超声破体后溶出,使水中的细菌总数增多;水蚤类浮游动物死体的溶出物导致水样中有机物浓度增大;超声处理使水蚤类浮游动物的活跃性显著降低,且随着超声时间的增加,水蚤类浮游动物活跃性下降;相同超声时间下,随着超声频率的增加,水蚤类浮游动物活跃性降低;夏季和冬季时,投加预氧化剂和缩短排泥周期都可以有效控制水蚤类浮游动物的丰度,且随着预氧化剂投加量的增加,浮游动物去除率增大,当预氧化剂投加量达到1.5 mg/L后,去除率趋于稳定,约为92%。

To deal with sensory problems and potential biosafety risks caused by daphnia zooplankton in waterworks,the microorganism and organic matter content released from dead daphnia zooplankton in effluent of sedimentation tank,the effects of ultrasonic time and ultrasonic frequency on daphnia zooplankton,and the control of daphnia zooplankton by pre-oxidation and sludge discharge cycle were investigated.Bacteria carried by daphnia zooplankton in the effluent from the sedimentation tank of the waterworks were released after ultrasonic breakage,which increased the total number of bacteria in the water.The leachate from the dead daphnia zooplankton bodies led to an increase in the concentration of organic matter in the water sample.Ultrasonic treatment significantly reduced the activity of daphnia zooplankton,and the activity of daphnia zooplankton decreased with increasing ultrasonic time.At the same ultrasonic time,the activity of daphnia zooplankton decreased with the increase of the ultrasonic frequency.Both the pre-oxidation and shortening the sludge discharge cycle could effectively control the growth of daphnia zooplankton in summer and winter,and the removal efficiency of daphnia zooplankton increased with the increase of the pre-oxidant dosage.When the pre-oxidant dosage reached 1.5 mg/L,the removal efficiency tended to be stable at approximately 92%.