白骨壤模拟湿地系统中磷的分配循环及其净化效应

Phosphorus cycling in a simulated wastewater-affected mangrove(Avicennia marina) wetland system

在温室中建立红树林植物白骨壤模拟湿地系统 ,分别用正常、5倍和 10倍 3种不同浓度的人工配置的污水每周定时定量对模拟系统进行污灌 1a。研究营养污染物 P在系统中的分配、循环及其被净化的效果。结果表明 :随污水处理浓度的升高 ,被更换的潮汐水中的含 P量和土壤含 P量都有明显提高 ;植物体各部分含 P量的高低顺序排列为 :叶 >茎 >根 ;在植物 -土壤系统中4个组分 CA0 、CA1 、CA5和 CA1 0 植物中 P元素的周转期依次为 4 .70 a、4 .6 1a、3.80 a和 5 .4 4 a;模拟植物 -土壤系统对污水中 P的净化效果显著 ,CA1 、CA5和 CA1 0 组的净化率分别为 81.2 3%、94 .4 0 %和 95 .6 3%。

A greenhouse experiment was conducted to investigate the cycling of phosphorus in an artificial mangrove wetland system receiving P-containing “wastewater”. Avicennia marina was selected as the only tested mangrove plant species, which grew in tanks containing soils collected from a mangrove tidal wetland in Shenzhen, South China. Artificial seawater with salinity of 15‰ was pumped into and out of the tanks at regular intervals to simulated semi-diurnal tidal conditions. Synthetic wastewater containing various levels of phosphorus (control, C 1, C 5 and C (10)) was discharged into the artificial wetland twice a week for a year.The results show that large amounts of phosphorus in the “wastewater” were removed by the soil after entering the artificial wetland system and the amount of soil-retained phosphorus increased with increasing content of phosphorus in the importing wastewater although the amount of phosphorus remained in the artificial tidal water also increased with increasing content of phosphorus in the importing wastewater. In general, the content of phosphorus in different organs was in the following decreasing order: leaf>stem>root. However, the content of phosphorus in different organs of the mangrove plant was not significantly different among the different wastewater treatments. This indicates that the retention of phosphorus by the mangrove plant was predominantly through the increased biomass rather than through the increased content of phosphorus in the plant organs. The total amount of phosphorus retained by the plant increased with increasing content of phosphorus in the importing wastewater (from control to C 5) and then decreased (from C 5 to C (10)). The work here has demonstrated that artificial wetland system had good effects on removing phosphorus from the synthetic wastewater. The removal rates were 81.23%、94.40% and 95.63% for treatments C 1, C 5 and C (10), respectively. Therefore, this study has implications for the management of wastewater using mangrove wetlands.