Novel enhanced primary treatment (EPT) of combined sewer overflow (CSO) using combinations of oxidants and coagulants

改善市政水管理是确保加拿大湖泊和河流可持续生态未来的关键因素，这些湖泊和河流覆盖了加拿大约12%的表面积。混合下水道溢流产生了大量污染物，特别是在严重潮湿的天气条件下，由于气候变化现象，这种情况在未来几年可能会更加频繁。目前绕过CSO或通过仅由混凝剂强化的初级处理来部分处理这些水流的做法，已将总悬浮固体(TSS)和大肠杆菌等一些参数的浓度提高到超过安全排放到河流的监管要求。这种违反监管要求的行为可能会对接收水环境生物造成危险后果。除了受管制的污染物外，由于在各种产品中的广泛使用，在民间社会组织中发现的浓度较高的微污染物和纳米材料可能对人类、鱼类和其他水生生物构成风险。因此，应评估它们的去向和清除机制，并制定在释放前降低其浓度的战略。为了进一步加强对民间社会组织的处理，有必要加强初级沉淀池的沉淀和氧化/消毒能力。本研究考虑的化学添加剂将包括高铁酸盐(Fe(VI))，这是一种很有前途的双重氧化剂/混凝剂，以及过氧乙酸(PAA)作为氧化剂，与硫酸铝、聚合氯化铝或三氯化铁等混凝剂一起使用。拟议的NSERC合作研究和开发(CRD)计划将根据对实际情况的模拟和对民间社会组织中不同污染物对环境影响的预测，帮助决策者采取可持续发展战略。作为CRD计划的结果，高素质的人员将接受多学科专业知识的培训，这将加强艾伯塔省和加拿大在废水处理管理方面的能力。

Improved municipal water management is a critical element in securing a sustainable ecological future for Canadian lakes and rivers which cover about 12% of the surface area of Canada. Combined sewer overflows (CSOs) contribute a significant amount of pollutants especially at heavy wet weather conditions which may be more frequent in the coming years due to the climate change phenomenon. Current practices of bypassing the CSOs or partially treating these flows through primary treatment enhanced only by coagulants have elevated the concentrations of some parameters like total suspended solids (TSS) and E.coli beyond the regulatory requirements of safe discharge to the river. This violation to the regulatory requirements can pose dangerous consequences to the receiving aquatic environment organisms. In addition to the regulated pollutants, micropollutants (MPs) and nanomaterials (NMs) found at elevated concentrations in CSOs as a result to their extensive usage in a wide range of products can pose risks on humans, fish and other aquatic life. Consequently, their fate and removal mechanisms should be assessed, and strategies to reduce their concentrations prior to their release should be developed. In order to further enhance the treatment of CSOs, there is an essential need to enhance both the settling and the oxidation/ disinfection capabilities in primary sedimentation tanks. Chemical additions considered in this study will include ferrate (Fe(VI)) which is a promising dual oxidant/coagulant and peracetic acid (PAA) as an oxidant applied in conjunction with coagulants such as aluminum sulfate, polyaluminum chloride, or ferric chloride. The proposed NSERC Collaborative Research and Development (CRD) Program will assist decision-makers to adopt sustainable development strategies based on the simulation of actual conditions and the predictions of the impact of different pollutants in CSOs on the environment. As a result of this CRD Program, highly qualified personnel will be trained with multidisciplinary expertise that will strengthen Alberta's and Canada's capacities in wastewater treatment management.