Ament Michael R, Hurley Stephanie E, Voorhees Mark, Perkins Eric, Yuan Yongping, Faulkner Joshua W, Roy Eric D
Department of Plant and Soil Science, University of Vermont, Burlington, VT 05405, USA.
Gund Institute for Environment, University of Vermont, Burlington, VT 05405, USA.
ACS ES T Water. 2021 Mar 12;1(3):688-697. doi: 10.1021/acsestwater.0c00178.
Green stormwater infrastructure like bioretention can reduce stormwater runoff volumes and trap sediments and pollutants. However, bioretention soil media can be both a sink and source of phosphorus (P). We investigated the potential tradeoff between hydraulic conductivity and P sorption capacity in drinking water treatment residuals (DWTRs), with implications for bioretention media design. Batch isotherm and flow-through column experiments were used to quantify the maximum P sorption capacity (S) and rate of P sorption for three DWTR sources. S values varied greatly among DWTR sources and methodologies, which has implications for regulatory standards. We also conducted a large column experiment to determine the hydraulic and P removal effects of amending bioretention media with solid and mixed layers of DWTRs. When applied to bioretention media, the impact of DWTRs on hydraulic conductivity and P removal depended on layering strategy. Although DWTR addition in solid and mixed layer designs improved P removal, the solid layer restricted water flow and exhibited incomplete P removal, while the mixed layer had no effect on flow and removed ~100% of P inputs. We recommend that DWTRs be mixed with sand in bioretention media to simultaneously achieve stormwater drainage and P reduction goals in green stormwater infrastructure.
像生物滞留这样的绿色雨水基础设施可以减少雨水径流量，并截留沉积物和污染物。然而，生物滞留土壤介质可能既是磷（P）的汇，也是磷的源。我们研究了饮用水处理残余物（DWTRs）的水力传导率和磷吸附能力之间的潜在权衡，这对生物滞留介质设计具有重要意义。采用批量等温线和流通柱实验来量化三种DWTR来源的最大磷吸附容量（S）和磷吸附速率。S值在DWTR来源和方法之间差异很大，这对监管标准有影响。我们还进行了一个大型柱实验，以确定用DWTRs的固体层和混合层改良生物滞留介质的水力和磷去除效果。当应用于生物滞留介质时，DWTRs对水力传导率和磷去除的影响取决于分层策略。虽然在固体层和混合层设计中添加DWTRs提高了磷去除率，但固体层限制了水流，且磷去除不完全，而混合层对水流没有影响，并去除了约100%的磷输入。我们建议在生物滞留介质中将DWTRs与沙子混合，以在绿色雨水基础设施中同时实现雨水排水和磷减少目标。
