废砖块作为人工湿地填料的除磷能力研究

对废砖块的物理化学特性进行了分析,并对其进行了磷素吸附能力试验,结果表明,废砖块适于湿地微生物的富集和植物的生长且具有较高的磷素吸附能力.通过构建以废砖块为填料的垂直流人工湿地系统考察并初步探索了其对生活污水中磷素的去除效果和去除机制.结果表明,当水力负荷为5 cm·d-1、运行时间为1 a时,湿地系统除磷效率在90%以上,且效果稳定;废砖块的吸附沉淀作用是湿地系统除磷的主要途径,而植物和微生物直接吸收所起的作用不大;被截留磷素在湿地填料层中具有明显的空间特征,对废砖块中的无机磷形态分析结果表明,废砖块中能与磷素发生沉淀反应的元素含量和其在废砖块中的化学形态是影响其吸附沉淀磷素作用途径的重要因素.因此,废砖块是人工湿地污水处理系统构建过程中较为理想的填料.

Study on Phosphorus Removal Capability of Constructed Wetlands Filled with Broken Bricks

Physico-chemical properties of broken bricks (BB) were determined, as well as its phosphorus adsorption ability. The results showed that BB was appropriate for enrichment of microorganisms and growth of plants as filter medium in CWs, in addition, BB had high phosphorus adsorption ability. A vertical subsurface flow constructed wetland (VSSF) filled with BB was constructed in order to investigate the phosphorus removal effect of domestic sewage, and the phosphorus removal mechanism of VSSF was also explored. The results showed that the phosphorus removal rate of VSSF was more than 90%, which remained stable when the hydraulic loading rate was 5 cm·d^-1 and the running time was 1 a; adsorption and precipitation within BB played the greatest role in phosphorus removal; distribution characteristics of total phosphorus in the filter media were attributed to the vertical flow state of wastewater in the system, besides, the contents and chemical forms of elements which could precipitate with phosphorus should be principal factors for the phosphorus removal processes of BB. Therefore, BB might be an ideal filter medium used in CWs.