人工湿地的磷去除机理

人类生产和生活所产生的磷负荷导致了全中国范围湖泊的富营养化,控制此磷负荷的廉价而有效的具有非常广阔的应用前景技术是人工湿地技术。人工湿地中的磷的存在形态主要有有机磷(生物态和非生物态的)、磷酸、可溶性磷酸盐和不溶性磷酸盐。文章总结了人工湿地中的磷去除机理,在防渗人工湿地系统中,主要的磷去除机理包括化学作用(如沉淀作用和吸附作用);生物作用(如植物吸收作用和微生物吸收与积累作用)和物理作用(如沉积作用)。在未防渗的人工湿地系统中,湿地系统和周围水体(如地下水)的交换量对湿地的磷去除有重要的影响。通常情况下,物理作用和化学作用是人工湿地中最主要的磷去除途径。人工湿地中微生物对磷的去除作用的大小和其所处环境中的氧状态密切相关,植物吸收对磷的去除作用的大小和收割频率与时期、进水负荷、植物物种和气候条件等有关。

Phosphorus removal mechanism of constructed wetland

Anthropogenic phosphorus (P) loads have been implicated in eutrophication of lakes throughout China. One technology that holds considerable promise for controlling these loads in a cost-effective manner is the use of constructed wetlands. Phosphorus (P) in constructed wetland including biotic organophosphorus, abiotic organophosphorus,phosphorus acid,soluble phosphate and insoluble phosphate. The P removal mechanism in the constructed wetland with a leak-proof layer consists of chemical function (such as precipitation and adsorption),biological function (such as plant assimilation,microbe assimilation and accumulation) and physical function (such as sedimentation),is reviewed in this paper. In a constructed wetland without a leak-proof layer, the P ex- change with the surrounding environments has significant effects on the P removal rate. Generally, physical and chemical functions are the major P removal mechanism in constructed wetland. Microbe function for P removal in constructed wetland is significantly correlated with the surrounding oxygen situation. Plant assimilation function for P removal in constructed wetland is correlated with harvest frequency and period,influent load,plant species and climate condition.