| 水淬渣人工湿地强化除磷作用研究 |
| 摘要点击 1922 全文点击 1555 投稿时间：2008-09-12 修订日期：2008-11-15 |
| 查看HTML全文
查看全文 查看/发表评论 下载PDF阅读器 |
| 中文关键词 湿地基质 除磷 水淬渣 水力停留时间 污染负荷 |
| 英文关键词 wetland matrix phosphorus removal water-granulated slag(WGS) hydraulic residence time(HRT) pollution load |
|
| 中文摘要 |
| 研究了水淬渣的磷吸附-解吸效果，构建了以水淬渣为主要基质的模拟垂直流人工湿地系统，分析了水力停留时间（HRT）和污染负荷变化对污水中磷去除的影响，探讨了湿地上行、下行流单元各层基质的除磷贡献.结果表明，水淬渣基质的磷饱和吸附量为3 333 mg·kg-1，其水溶性钙含量为0.084%，pH值为7.54，适合作为湿地除磷基质.HRT与磷除去率呈正相关，当HRT从1 d缩短为0.5 d时，TP去除率降低5.9%～4.7%，当HRT从2 d缩短为1 d时，TP去除率降低2.4%～4.7%，HRT为1 d条件下，水淬渣湿地的磷去除率>85%，说明无限延长HRT无益于强化除磷，适宜的HRT为1 d.在进水浓度稳定的条件下，进水污染负荷与磷去除率呈负相关，当污染负荷范围在12.2～36.8 g·(m2·d)-1时，水淬渣湿地的磷除去率可维持在85%，当污染负荷达到48.9 g·(m2·d)-1后，水淬渣湿地的磷除去率下降至65%，当污染负荷<36.8 g·(m2·d)-1时，水淬渣湿地的磷去除率>82%，说明高污染负荷可抑制基质表面及孔隙中Ca、Al等吸附磷的活跃位点，适宜的进水污染负荷为24.5～36.8 g·(m2·d)-1.表层铺设水淬渣、下层铺设常规基质的级配方式有利于垂直流湿地除磷，下行流和上行流单元的表层水淬渣基质磷吸附量可达0.17 mg·kg-1和0.05 mg·kg-1，在表层基质磷吸附饱和后可灵活更换，有效延长湿地除磷寿命. |
| 英文摘要 |
| The phosphorus adsorption and desorption effects of water-granulated slag (WGS) were studied. A simulated vertical flow constructed wetland system was constituted using WGS as the main matrix. The influences of hydraulic residence time (HRT) and pollution load on phosphorus removal were investigated. The contributions of phosphorus removal of different horizon layers in up-flow and down-flow matrixes were studied. The results showed that WGS was a kind of adaptive desorption material for wetland due to its high saturated phosphorus adsorptive capacity (3 333 mg·kg-1). The content of soluble calcium of WGS is 0.084%, which provides a suitable pH (7.54) for microbes and plants growth in wetland. The HRT is in positive correlation with phosphorus removal rate. The phosphorus removal rates decrease 5.9%-4.7% and 2.4%-4.7% when HRT decreases from 1 d to 0.5 d and form 2 d to 1 d, respectively. The phosphorus removal rates exceed 85% at 1 d HRT in WGS wetland. That means the optimized HRT is 1 d, and extending HRT infinitely is not helpful to phosphorus removal. The pollution load is in negative correlation with phosphorus removal rate under the conditions of steady influx concentration. The phosphorus removal rates maintain 85% when the pollution load is from 12.2 g·(m2·d)-1 to 36.8 g·(m2·d)-1. When the pollution load increases to 48.9 g·(m2·d)-1, the phosphorus removal rate decreases to 65%. The phosphorus removal rate exceeds 82% when the pollution load is less than 36.8 g·(m2·d)-1. That means higher pollution load will cause the calcium and aluminum active points of phosphorus adsorption shielded, which exist both on matrix surface and in inner pores. The range of optimized pollution load is from 24.5 g·(m2·d)-1 to 36.8 g·(m2·d)-1. The graduation mode of WGS in top layer and conventional materials in lower layer is helpful to phosphorus removal in vertical flow wetland. The phosphorus adsorptive capacities in up-flow and down-flow unit are 0.17 mg·kg-1 and 0.05 mg·kg-1 respectively. The WGS can be changed freely when the saturated adsorption occurs, which will extend the wetland service life. |
