Ecological Engineering Systems for Nutrient Reduction and Recovery from Agricultural Wastewater Sources

养分从农业集水区向地表水和地下蓄水层的迁移对公众健康和环境构成重大威胁，并在饮用水处理和丧失娱乐潜力方面带来高昂的经济成本。国际联合委员会(IJC，2014)发布的一份报告指出，农业径流可以为水道带来巨大的营养负荷，并规定农业作业是磷负荷的主要贡献者之一，对伊利湖最近严重的藻类水华负有责任。该报告描述了农业系统已经从净磷汇演变为现在大多数农场出口净磷的地方。加拿大各地的湖泊和河流都记录到磷含量升高，并导致蓝藻水华的发展，这导致毒素被释放到地表水中。这项研究计划致力于从农业废水中减少和回收氮和磷，并由四个相互关联的目标组成。第一个目标是开发一种捕获和回收溶解磷的技术，作为人工湿地技术的一个组成部分。该假说认为，利用缓释阳离子(即：钙、镁、铁、铝)与沉淀池或过滤介质相结合，并定期进行除泥/清除，然后再施入土地，可以使农业流域磷的循环闭合。技术开发将从实验室到中试再到现场规模。第二个目标是利用代表典型农业废水的全仪器化人工湿地系统在安大略省东部的合作地点表征N和P的负荷和分级(总、颗粒、溶解、N循环)：种植系统排水、牛肉生产径流和乳制品生产洗涤水。第三个目标是研究处理农业废水的人工湿地系统中的N/P衰减机理和模型去除速率。最终目标是在现有的合作地点应用、验证和调整P捕获技术。这三个现场都配备了完整的流量(带有深度记录仪的V型槽堰、水泵运行时间记录仪)和水质采样(太阳能复合采样器、地下水压力计、零张力蒸渗仪)的仪器。所有水质分析工作将在渥太华大学的环境工程实验室按照标准方法进行。HQP培训是研究计划的核心，有2名博士、6名硕士、以及几名工程硕士和本科生参与了磷恢复技术的开发、湿地特性和建模活动。与政府和行业的强大合作为技术转移提供了强大的平台。

Nutrient migration from agricultural catchments to surface water bodies and to groundwater aquifers present a significant threat to public health and to the environment as well as representing high economic costs in terms of drinking water treatment and loss of recreational potential. A report published by the International Joint Commission (IJC, 2014) states that agricultural runoff can contribute significant nutrient loads to watercourses and stipulates that agricultural operations are one of the major contributors of phosphorus loads responsible for the recent severity of algal blooms in Lake Erie. The report describes agricultural systems having evolved from being net phosphorus sinks to where there is now net phosphorus being exported from most farms. Heightened levels of phosphorus have been recorded in lakes and rivers across Canada and have resulted in the development of cyanobacterial blooms, which result in toxins being released into surface water bodies. This research program addresses N and P reduction and recovery from agricultural wastewaters and consists of four inter-related objectives. The first objective is to develop a technology to capture and recover dissolved P as a component to constructed wetland technology. The hypothesis is that the use of a source of slow-release cations (i.e. Ca2+, Mg2+, Fe2+/3+, Al3+) coupled with either a sedimentation pond or filtration media and periodic desludging/removal followed by land application can close the loop on P in agricultural drainage basins. Technology development will evolve from lab to pilot to field scale. The second objective is to characterize N and P loading and fractioning (total, particulate, dissolved, N cycling) at cooperator sites in Eastern Ontario with fully instrumented constructed wetland systems representing typical agricultural wastewaters: cropping system drainage, beef production runoff and dairy production washwaters. The third objective is to study N/P attenuation mechanisms and model removal rates in the constructed wetland systems treating agricultural wastewaters. The final objective is to apply, validate and adapt the P capture technology at the existing cooperator sites. The three field sites are fully instrumented for flow (v-notch weirs with depth loggers, pump runtime loggers) and water quality sampling (solar powered composite samplers, groundwater piezometers, zero-tension lysimeters). All water quality analytical work will be conducted at the University of Ottawa's environmental engineering laboratories following Standard Methods. HQP training is central to the research program, with 2 Ph.D, 6 M.A.Sc., and several M.Eng and Undergraduate students implicated in the development of the P-recovery technology, wetland characterization and modelling activities. Strong collaboration with government and industry provides a strong platform for technology transfer.