Meng Yike, Wang Yuan, Wang Chuanyue
College of Civil and Transportation Engineering, Hohai University, Nanjing 210098, China.
College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing 210098, China.
Polymers (Basel). 2021 Jan 17;13(2):283. doi: 10.3390/polym13020283.
Bioretention systems are frequently employed in stormwater treatment to reduce phosphorus pollution and prevent eutrophication. To enhance their efficiency, filter additives are required but the currently used traditional materials cannot meet the primary requirements of excellent hydraulic properties as well as outstanding release and adsorption capacities at the same time. In this research, a polyurethane-biochar crosslinked material was produced by mixing the hardwood biochar (HB) with polyurethane to improve the performance of traditional filter additives. Through basic parameter tests, the saturated water content of polyurethane-biochar crosslinked material (PCB) was doubled and the permeability coefficient of PCB increased by two orders of magnitude. Due to the polyurethane, the leaching speed of phosphorus slowed down in the batching experiments and fewer metal cations leached. Moreover, PCB could adsorb 93-206 mg/kg PO at a typical PO concentration in stormwater runoff, 1.32-1.58 times more than HB, during isothermal adsorption experiments. In the simulating column experiments, weaker hydropower reduced the PO leaching quantities of PCB and had a stable removal rate of 93.84% in phosphate treatment. This study demonstrates the potential use of PCB as a filter additive in a bioretention system to achieve hydraulic goals and improve phosphate adsorption capacities.
生物滞留系统常用于雨水处理，以减少磷污染并防止富营养化。为提高其效率，需要过滤添加剂，但目前使用的传统材料无法同时满足优异的水力性能以及出色的释放和吸附能力的主要要求。在本研究中，通过将硬木生物炭（HB）与聚氨酯混合制备了一种聚氨酯-生物炭交联材料，以改善传统过滤添加剂的性能。通过基本参数测试，聚氨酯-生物炭交联材料（PCB）的饱和含水量增加了一倍，其渗透系数提高了两个数量级。由于聚氨酯的作用，在分批实验中磷的浸出速度减慢，浸出的金属阳离子减少。此外，在等温吸附实验中，对于雨水径流中典型的PO浓度，PCB能够吸附93-206mg/kg的PO，比HB多1.32-1.58倍。在模拟柱实验中，较弱的水力降低了PCB的PO浸出量，在磷酸盐处理中具有93.84%的稳定去除率。本研究证明了PCB作为生物滞留系统中过滤添加剂以实现水力目标并提高磷酸盐吸附能力的潜在用途。
