Wastewaters contain complex mixtures of chemicals, which can cause adverse toxic effects in the receiving environment. In the present study, the toxicity removal during wastewater treatment at seven municipal wastewater treatment plants (WWTPs) was investigated using an effect-based approach. A battery of eight bioassays was applied comprising of cytotoxicity, genotoxicity, endocrine disruption and fish embryo toxicity assays. Human cell-based CALUX assays, transgenic larval models and the fish embryo toxicity test were particularly sensitive to WWTP effluents. The results indicate that most effects were significantly reduced or completely removed during wastewater treatment (76–100%), while embryo toxicity, estrogenic activity and thyroid disruption were still detectable in the effluents suggesting that some harmful substances remain after treatment. The responsiveness of the bioassays was compared and the human cell-based CALUX assays showed highest responsiveness in the samples. Additionally, the fish embryo toxicity test and the transgenic larval models for endocrine disrupting effects showed high responsiveness at low sample concentrations in nearly all of the effluent samples. The results showed a similar effect pattern among all WWTPs investigated, indicating that the wastewater composition could be rather similar at different locations. There were no considerable differences in the toxicity removal efficiencies of the treatment plants and no correlation was observed with WWTP characteristics, such as process configuration or sludge age. This study demonstrated that a biotest battery comprising of multiple endpoints can serve as a powerful tool when assessing water quality or water treatment efficiency in a holistic manner. Rather than analyzing the concentrations of a few selected chemicals, bioassays can be used to complement traditional methods of monitoring in the future by assessing sum-parameter based effects, such as mixture effects, and tackling chemicals that are present at concentrations below chemical analytical detection limits.

中文翻译：

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基于效果的废水处理过程中毒性去除的评估

废水中含有复杂的化学混合物，可能在接收环境中造成不利的毒性影响。在本研究中，使用基于效果的方法研究了七个市政污水处理厂（WWTP）在污水处理过程中的毒性去除。进行了八次生物测定，包括细胞毒性，基因毒性，内分泌破坏和鱼胚毒性测定。基于人细胞的CALUX分析，转基因幼虫模型和鱼胚毒性试验对污水处理厂废水特别敏感。结果表明，在废水处理过程中，大多数影响被显着降低或完全消除（76-100％），而胚胎毒性，在废水中仍可检测到雌激素活性和甲状腺破坏，这表明治疗后仍残留一些有害物质。比较了生物测定的响应度，并且基于人细胞的CALUX测定在样品中显示出最高的响应度。此外，鱼胚毒性试验和转基因幼虫内分泌干扰作用模型在几乎所有废水样品中均以低样品浓度显示了高响应性。结果显示，在所有调查的污水处理厂中，其影响模式相似，表明废水的组成在不同地点可能非常相似。处理厂的除毒效率没有显着差异，并且与污水处理厂的特征（如工艺配置或污泥龄）也没有相关性。这项研究表明，在以整体方式评估水质或水处理效率时，由多个端点组成的生物测试电池可以用作强大的工具。通过分析基于总和参数的效应（例如混合效应）并处理浓度低于化学分析检测极限的化学物质，生物测定法可用于分析未来的传统监测方法，而不是分析某些选定化学物质的浓度， 。