土壤中铅的吸附-解吸行为研究进展

Advance in the studies of Pb adsorption and desorption in soils

铅是重要的土壤重金属污染元素之一,了解铅在土壤中的物理化学行为,有利于预防和修复土壤的铅污染。土壤中铅的吸附-解吸行为,依吸附机理的不同,分为专性吸附和非专性吸附。土壤铅吸附的机理还存在不同的观点,如水解吸附/非水解吸附机理,单分子吸附/双分子吸附机理等。影响土壤中铅吸附-解吸行为的主要因素,有土壤矿物组成、土壤有机质、pH、温度、竞争离子等。文章最后对描述土壤铅吸附过程的主要数学方程(Langmuir 方程、Freundlich 方程和 Temkin 方程)作了论述。

Lead (Pb) pollution is an increasing public concern. Understanding chemical and biochemical behavior of lead in soil is important for preventing and remediation of Pb contamination. This paper summarizes the mechanism of Pb adsorption and desorption in soils. Specific sorption and nonspecific sorption was recognized, and there are still different opinions about Pb2+ adsorption mechanisms such as hydrolyzed /unhydrolyzed adsorption and monodentate /bidentate reactions. The main factors affect Pb adsorption such as soil particle composition, organic matter, pH, temperature, and competitive cations are discussed. Finally some sorption isotherms are described.