生物炭对去除生物滞留池氨氮及雨水持留的影响
Biochar Incorporation into Bioretention for Enhanced Ammonium Removal and Runoff Retention

为了加强对城市雨水的处理，提出了将生物炭添加于生物滞留池填料土，以黄松木为原料，在550℃条件下制备生物炭，分析生物炭对生物滞留池填料土的理化性质和雨水中氨氮吸附能力的影响；测量了对照填料土和添加了4%生物炭的改良填料土在-15 300~0 cm H2O土壤水吸力范围的水分特征曲线；采用圆盘入渗仪和DISC软件测算了田间生物滞留池对照和改良填料土的导水率.研究结果表明，生物炭的施用提高了酸性填料土的pH值，降低填料土容重达7%，增加总孔隙率约28%，增大阳离子交换量达33%；施用生物炭后，填料土对氨氮的去除率从-26%~28%提高到50%~90%；生物炭的施用使填料土有效水含量从0.016 cm3/m-3提高到0.063 cm3/m-3，饱和导水率增大了1.5倍；生物炭可从水质和水量两方面提高生物滞留池对城市雨水中氨氮的去除，并有助于城市雨洪控制.
：Incorporating biochar into bioretention filter media was proposed to enhance urban stormwater treatment. Pinewood biochar pyrolysed at 550℃ was used to investigate its impact on the physicochemical properties of bioretention filter media and their ammonium sorption capacities in artificial stormwater. Water retention curves of the control and 4% biochar-amended filter media were measured at -15 300 to 0 cm H2O suction pressure. Hydraulic conductivities of two filter media were measured at field pilot-scale bioretention using a tension disc infiltrometer and analysed with DISC software. The results indicate that biochar amendment increased the pH of the acid filter medium, decreased bulk density by 7%, and increased total porosity and cation exchange capacity by 28% and 33%, respectively. Biochar incorporation increased ammonium removal of the control filter medium from -26%-28% to 50%-90%. The Freundlich model fitted the ammonium sorption isotherms of the three materials well. Biochar increased available water content of the control filter medium from 0.016 to 0.063 cm3/m-3 and saturated hydraulic conductivity by 1.5 times. The Van Genuchten model fitted the water retention curves of the control and biochar-amended filter media well. Incorporating biochar into bioretention filter media can enhance nitrogen removal from the perspective of water quality and quantity and benefit urban rainwater flood control