Heavy Metals Removal from Swine Wastewater Using Constructed Wetlands with Horizontal Sub-Surface Flow

The removal efficiency of Cu and Zn from swine wastewater was evaluated as effected by three variables: the hydraulic retention time (HRT) (24, 48, 72 and 96 hours), two different plant species (Typha domingensis Pers. and Eleocharis cellulosa) and two different sizes of filter media (5 and 15 mm) using a horizontal sub-surface flow constructed wetland. From the results, a significant difference was observed in the removal efficiency of Cu and Zn with respect to different hydraulic retention times. The best results were obtained in the HRT of 96 hours for Zn where 96% removal of Zn with Typha domingensis Pers. specie with gravel of 15 mm (experimental unit 6) was achieved. For Cu, at 72 hours of HRT, the efficiency was nearly 100% in five of the six study units (1, 2, 3, 5 and 6). In contrast, in experimental unit 4 with gravel of 15 mm and without plants, only 86% Cu removal was achieved.

潜流园林人工湿地脱氮除磷效果正交试验

以柳树、湿地填料构建潜流型园林人工湿地,考察其脱氮除磷效果,为优化滤池结构,及其应用推广确定最佳运行条件。通过设计L9(34)正交试验,研究了填料、填料铺装方式、植物和水力停留时间(HRT)4个因素对考察指标的影响显著性及优选条件。运用SPSS19.0软件对试验数据的极差、回归分析表明,填料、填料铺装方式、植物、水力停留时间与潜流式园林人工湿地氮、磷去除率间呈显著的线性相关关系,相关系数R2分别为0.996、0.967;各因素对总氮去除率的影响程度排序为:填料、水力停留时间、填料铺装方式、植物;对总磷去除率的影响程度排序为:填料、填料铺装方式、水力停留时间、植物;潜流型园林人工湿地总氮去除率最高的操作条件为:陶粒和页岩的组合均匀混合铺装,种植馒头柳,HRT为9 d,TN去除率预测值为81%;有利于总磷去除率的最佳操作条件为:陶粒和页岩异垂直分层方式填装,植物为旱柳,HRT为6 d,TP去除率预测值为78.2%。

潜流园林人工湿地基质对水中磷的吸附行为

通过研究海蛎壳、燃煤炉渣、流化床炉渣和建筑废砖对水中磷的等温吸附行为和吸附动力学特征,探讨4种基质作为潜流园林人工湿地除磷基质的理论基础.结果表明:海蛎壳、燃煤炉渣、流化床炉渣、建筑废砖的饱和磷吸附量分别为4.502,4.195,4.041,3.683 mg/g,溶液初始磷浓度影响海蛎壳、流化床炉渣、燃煤炉渣、建筑废砖对磷的吸附过程.海蛎壳、燃煤炉渣对磷的等温吸附更符合Freundlich模型,吸附能力大小排序为海蛎壳、燃煤炉渣、流化床炉渣、建筑废砖.准一级动力学方程更好地描述了海蛎壳对磷的吸附动力学特征,燃煤炉渣、流化床炉渣、建筑废砖更符合准二级动力学方程,吸附作用受化学作用控制.