摘要
城市雨水径流中重金属逐渐成为环境水体中重金属污染的重要来源之一。选择细沙、沸石、砂土、石英砂分别和木质素以一定比例混合组成的复合生物滞留介质为研究对象,采用人工模拟雨水,研究了不同复合生物滞留介质对雨水径流中重金属的净化效果及其影响因素。结果表明,4种复合介质对Pb2+的去除率均超过98%,且去除率较稳定,细沙复合介质对Cu2+的平均去除率为98.5%,对重金属的去除能力大小顺序为Pb2+>Cu2+>Zn2+>Cd2+,沸石复合介质对重金属的去除能力大小顺序为Pb2+>Cd2+>Cu2+>Zn2+,沙土复合介质对重金属的去除能力大小顺序为Pb2+>Cd2+>Zn2+>Cu2+,石英砂复合介质对Pb2+、Zn2+和Cd2+的去除率均超过99%。雨水径流中重金属浓度、介质高度和降雨历时对复合生物滞留介质去除重金属的影响较小。酸性条件下,4种复合介质均存在明显的重金属溶出过程,pH越低,复合介质中重金属溶出量越多,且同种复合介质中不同重金属元素的溶出浓度变化过程相似。
Heavy metal from urban stormwater runoff has become one of the important sources of heavy metal pollution in urban watershed.Composite bioretention medias,sand,zeolite,sandy soil and quartz sand mixed with lignin respectively,were selected as research objects,adopting synthetic stormwater runoff as influent with different heavy metal（copper,zinc,lead,and cadmium） concentration.The removal efficiency of different composite bioretention media on heavy metals from stormwater runoff and its influencing factors were investigated.The experimental results showed that the removal efficiency of Pb by four kinds of composite bioretention media were all stable.The removal efficiency of Cu2 ＋by sand composite medium was better and the average removal efficiency was 98.5%,removal efficiency of Pb2 ＋,Zn2 ＋and Cd2 ＋by quartz sand composite medium was better（all over99%）.The sequence of heavy metals removal efficiency by sand composite medium was Pb2 ＋ Cu2 ＋ Zn2 ＋Cd2 ＋,zeolite composite medium was Pb2 ＋ Cd2 ＋ Cu2 ＋ Zn2 ＋,and sandy soil composite medium was Pb2 ＋Cd2 ＋ Zn2 ＋ Cu2 ＋.Influent heavy metals concentration,composite bioretention media height and rainfall duration had minor effect on heavy metals removal.Under acidic conditions,there were obvious heavy metals dissolution processes in four kinds of composite bioretention media.The lower of the pH value,the more the dissolution of heavy metals,and the profiles of different heavy metal elements dissolution in the same medium was similar.
出处
《环境工程学报》
CAS
CSCD
北大核心
2015年第7期3086-3092,共7页
Chinese Journal of Environmental Engineering
基金
国家自然科学基金资助项目(51208022)
国家"水体污染控制与治理"科技重大专项(2011ZX07301-004-01)
北京市青年拔尖人才培育计划项目(21147514066)
关键词
生物滞留介质
重金属
雨水径流
bioretention media
heavy metals
stormwater runoff
