生物土壤结皮的表征分析与吸附去除水体中镉的试验

Characterization Analysis of Biological Soil Crust and Experiment of Removal and Adsorption of Cadmium from Water Body

通过从四个典型南方稻田环境采集灌溉水,土壤和生物结皮。筛选出镉污染程度最轻的生物土壤结皮并对其进行表征分析以及去除水体中镉的性能研究,表明生物土壤结皮为生物组分和土壤矿质元素的复合体,具有大量表面官能团。性能研究表明吸附容量与平衡浓度基本呈线性关系,最大吸附容量为8.481 mg/g;对水溶液中镉的最大去除率为99.79%。对镉吸附最适pH值为7且去除率达87.03%。在含高钙环境下对镉具有选择性吸收特征,同时对于平均分子量数量级低于10~7的络合态镉亦有较好的去除效果。生物结皮对去除水体中的镉具有潜在价值。

The experiment showed that irrigation water, soil and biological soil crust （ BSC） were collected from four locations of typical paddy field environment in south China. According to the data of Cd concentration in BSC from four locations, BSC with the lowest level of Cd pollution was sieved, and its adsorptive property was characterized and tested. Result showed BSC was consisting of Biological components and mineral, and a large number of functional groups were on its surface. Adsorption capacity had a linear relation with equilibrium concentration, and the maximum adsorption capacity and remove rate was 8. 481 mg/g and 99.79% , respectively. BSC was able to remove 87.03% of Cd when pH value was 7. It presented the feature of preferential adsorption in high calcium ions system, and showed good removal efficiency of cadmium complex whose molecule weight was less than 10^7. In a result, BSC had potential value to remove the cadmium in water.