污水的青海弧菌Q67生物毒性检测及影响因素分析

Detection of Wastewater Ecotoxicity Using Virbrio qinghaiensis sp.-Q67 and Its Impact Factors Analysis

应用淡水发光细菌——青海弧菌Q67对氧化沟处理工艺各处理单元进出水的生物急性毒性进行检测,对污水急性毒性检测的影响因素进行了分析.结果表明,水样取回后立即进行发光细菌毒性实验,水样均显示为刺激发光效应,污水毒性被掩盖;将水样放置1 d后进行毒性实验,部分水样显现出抑制发光效应;将污水用0.45μm微滤膜过滤可以使水样的生物毒性更好地显现,提高了毒性检测结果的真实性和准确性;水样灭菌后,生物毒性趋于稳定;采用固相萃取富集污水中的有机物,可以很好地监测污水厂各处理单元进出水中有机物的急性毒性大小.各处理单元EC50值如下:细格栅出水为11.44;氧化沟进水为11.96;氧化沟出水为21.05;二沉池出水为16.06;UV消毒出水为15.17.污水厂的生物毒性主要在氧化沟工艺中去除,但是其工艺对生物毒性的去除十分有限.

In this study the luminescent bacteria Virbrio qinghaiensis sp.-Q67 was used to assess the acute toxicity of wastewater from different treatment processes of the oxidation ditch plants.The impact factors of detection were also been analyzed.The results indicated that all samples were showed stimulating effects when the acute toxicity of wastewater samples were tested immediately.When the acute toxicity was tested after one day,some samples showed inhibiting effects.When the samples of wastewater were treated with 0.45 μm membrane filtration,the acute toxicity could be monitored authentically and accurately.After sterilization,the acute toxicity of wastewater was stable during in the days of depositing.Organic material in wastewater could be enriched with solid-phase extraction.It could be well used to monitor ecotoxicity of organic substances in wastewater treatment units.The efficient concentration（EC50） values of progresses were as follows.The EC50 values of raw water,primary settler effluent,oxidation ditch effluent,secondary settler effluent and UV disinfection effluent were 11.44,11.96,21.05,16.06 and 15.17,respectively.The ecotoxicity of wastewater in the plant was removed by the process of oxidation ditch but the removal was very limited.