Department of Environmental Science, Baylor University, One Bear Place #97266, Waco, TX 76798, USA.
Chemosphere. 2013 Jun;92(1):38-44. doi: 10.1016/j.chemosphere.2013.03.007. Epub 2013 Apr 1.
Though decentralized on-site technologies are extensively employed for wastewater treatment around the globe, an understanding of effluent water quality impairments associated with these systems remain less understood than effluent discharges from centralized municipal wastewater treatment facilities. Using a unique experimental facility, a novel comparative analysis of effluent water quality was performed from model decentralized aerobic (ATS) and septic (STS) on-site wastewater treatment systems and a centralized municipal wastewater treatment plant (MTP). The ATS and STS units did not benefit from further soil treatment. Each system received common influent wastewater from the Waco, Texas, USA Metropolitan Area Regional Sewerage System. We tested the hypothesis that MTP effluent would exhibit higher water quality than on-site effluents, based on parameters selected for study. A tiered testing approach was employed to assess the three effluent discharges: select routine water quality parameters (Tier I), whole effluent toxicity (Tier II), and select endocrine-active compounds (Tier III). Contrary to our hypothesis, ATS effluent was not statistically different from MTP effluents, based on Tier I and III parameters, but reproductive responses of Daphnia magna were slightly more sensitive to ATS than MTP effluents. STS effluent water quality was identified as most degraded of the three wastewater treatment systems. Parameters used to assess centralized wastewater treatment plant effluent water quality such as whole effluent toxicity and endocrine active substances appear useful for water quality assessments of decentralized discharges. Aerobic on-site wastewater treatment systems may represent more robust options than traditional septic systems for on-site wastewater treatment in watersheds with appreciable groundwater - surface water exchange.
尽管分散式现场处理技术在全球范围内广泛应用于废水处理，但与集中式城市污水处理厂的废水排放相比，人们对这些系统产生的出水水质问题的了解仍不够充分。本研究采用独特的实验设施，对模型化分散式好氧（ATS）和化粪池（STS）现场废水处理系统与集中式城市污水处理厂（MTP）的出水水质进行了新颖的对比分析。ATS 和 STS 单元未受益于进一步的土壤处理。每个系统都接收来自美国德克萨斯州韦科市大都市区区域下水道系统的普通进水废水。我们基于所选研究参数检验了这样一个假设，即 MTP 出水的水质将优于现场出水。采用分层测试方法评估了三种废水排放物：选择常规水质参数（第 I 层）、全废水毒性（第 II 层）和选择内分泌活性化合物（第 III 层）。与我们的假设相反，根据第 I 层和第 III 层参数，ATS 出水在统计学上与 MTP 出水中并无差异，但大型溞的生殖反应对 ATS 出水中的毒性比 MTP 出水中更为敏感。STS 出水水质被确定为三种废水处理系统中最劣化的。用于评估集中式污水处理厂出水水质的参数，如全废水毒性和内分泌活性物质，似乎对分散式排放的水质评估有用。与传统化粪池系统相比，好氧现场废水处理系统在具有明显地下水-地表水交换的流域中，可能是现场废水处理更可靠的选择。
