Bioanalytical tools, namely in vitro bioassays, can be employed in tandem with chemical analyses to assess the efficacy of wastewater treatment and the potential for adverse effects from the discharges of wastewater into receiving waters. In the present study, samples of untreated wastewater (i.e., influent) and treated wastewater (i.e., effluent) were collected from two wastewater treatment plants and a wastewater treatment lagoon to investigate potential differences in treatment performance. In addition, grab samples of surface water were collected downstream of the lagoon discharge to evaluate the water quality in the receiving stream. After solid-phase extraction (SPE) using ion exchange columns for basic/neutral and acidic compounds, respectively, the extracts were analyzed for a suite of 16 indicator compounds. The two SPE extracts were combined for analysis of biological responses in four in vitro cell-based bioassays. The concentrations of several indicator compounds, including the estrogens, 17β-estradiol (E2) and 17α-ethinylestradiol (EE2), were below the limits of detection. However, androstenedione and estrone were detected in several influent samples. The concentrations of these steroid hormones and some of the other indicator compounds declined during treatment, but acesulfame K, carbamazepine, trimethoprim and DEET persisted in the effluent. The MTS-CellTiter 96® AQueous One Solution Cell Proliferation Assay (MTS) indicated that cell viability was not affected by exposure to the extracts. The Qiagen Nuclear Receptors 10-Pathway Reporter Array indicated that several cellular pathways were upregulated, with the greatest upregulation observed with the estrogen receptor (i.e., induction ratios of 12 to 47) and the liver X receptor (i.e., induction ratios of 10 to 45). The ERα CALUX assay indicated that estrogenic activity was lower in effluents compared to influents, but the expected improved removal of estrogenic activity during nitrification was not observed. The results of the Nrf2 Luciferase Luminescence Assay indicated a lower oxidative stress in the effluent samples, except for the lagoon. Overall, the present study further demonstrates that bioassays provide complementary information to chemical analyses and offer a way to assess treatment performance, even when target contaminants are not detected. There are thus advantages to using a combination of chemical analyses and in vitro bioassays to monitor the treatment efficiency of wastewater treatment plants and to predict the potential impacts of wastewater discharges into receiving waters.

生物分析工具，即体外生物测定，可与化学分析结合使用，以评估废水处理的功效以及废水排放到接收水体的潜在不利影响。在本研究中，从两个污水处理厂和一个污水处理池收集了未经处理的废水（即进水）和处理过的废水（即出水）的样品，以研究处理性能的潜在差异。此外，在泻湖排放下游采集地表水样本，以评估接收流中的水质。分别使用离子交换柱对碱性/中性和酸性化合物进行固相萃取 (SPE) 后，分析提取物中的 16 种指示化合物。将两种 SPE 提取物结合起来，在四种基于细胞的体外生物测定中分析生物反应。几种指示化合物的浓度，包括雌激素、17β-雌二醇 (E2) 和 17α-炔雌醇 (EE2)，均低于检测限。然而，在几个进水样品中检测到雄烯二酮和雌酮。这些类固醇激素和一些其他指示化合物的浓度在处理过程中下降，但乙酰磺胺酸钾、卡马西平、甲氧苄啶和避蚊胺持续存在于流出物中。MTS-CellTiter 96® AQueous One Solution 细胞增殖测定 (MTS) 表明细胞活力不受提取物暴露的影响。Qiagen 核受体 10 通路报告基因阵列表明，几种细胞通路被上调，用雌激素受体（即，诱导比为 12 至 47）和肝 X 受体（即，诱导比为 10 至 45）观察到最大的上调。急诊室α CALUX 分析表明，与进水相比，出水中的雌激素活性较低，但未观察到在硝化过程中雌激素活性的预期改善。Nrf2 萤光素酶发光测定的结果表明，除泻湖外，流出物样品中的氧化应激较低。总体而言，本研究进一步表明，生物测定为化学分析提供了补充信息，并提供了一种评估处理性能的方法，即使没有检测到目标污染物。因此，结合使用化学分析和体外生物测定来监测废水处理厂的处理效率并预测废水排放到接收水体的潜在影响是有优势的。