Key Lab of Northwest Water Resources, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Ecotoxicol Environ Saf. 2013 Nov;97:248-54. doi: 10.1016/j.ecoenv.2013.08.001. Epub 2013 Aug 26.
Luminescent bacterial test is a fast and sensitive method for acute toxicity assessment of water and wastewater. In this study, an improved toxicity testing method was developed using the freshwater luminescent bacteria Vibrio qinghaiensis sp.-Q67 that involved pretreatment of water samples with reverse osmosis (RO) to eliminate the interferences caused by nutrients in concentrated samples and to improve the reliability and sensitivity of the analysis. Because water samples contain low concentrations of several target toxic substances, rapid acute toxicity testing method that is commonly employed does not achieve enough sensitivity. The proposed RO pretreatment could effectively enrich organic and inorganic substances in water samples to enable a more effective and sensitive toxicity evaluation. The kinetic characteristics of toxicity of raw sewage and secondary effluent were evaluated based on the relative luminescence unit (RLU) curves and time-concentration-effect surfaces. It was observed that when the exposure time was prolonged to 8-h or longer, the bacteria reached the logarithmic growth stage. Hence, the stimulating effects of the coexisting ions (such as Na(+), K(+), NO3(-)) in the concentrated samples could be well eliminated. A 10-h exposure time in proposed Q67 test was found to quantitatively evaluate the toxicity of the organic and inorganic pollutants in the RO-concentrated samples.
发光细菌测试是一种快速、灵敏的水质和废水急性毒性评估方法。本研究采用青海弧菌（Vibrio qinghaiensis sp.-Q67）作为淡水发光细菌，对其进行了改进的毒性测试方法研究。该方法通过反渗透（RO）预处理水样，消除浓缩样品中营养物质引起的干扰，提高分析的可靠性和灵敏度。由于水样中几种目标毒性物质的浓度较低，常用的快速急性毒性测试方法灵敏度不够。所提出的 RO 预处理方法可以有效地富集水样中的有机和无机物质，从而实现更有效和灵敏的毒性评估。根据相对发光单位（RLU）曲线和时-浓度-效应面，评估了原污水和二级出水的毒性动力学特征。结果表明，当暴露时间延长至 8 小时或更长时间时，细菌进入对数生长期。因此，浓缩样品中共存离子（如 Na(+)、K(+)、NO3(-)）的刺激作用可以得到很好的消除。发现 10 小时的 Q67 测试暴露时间可定量评估 RO 浓缩样品中有机和无机污染物的毒性。
