摘要
采用平衡液吸附法及NH4OAC、EDTA解吸剂解吸法研究名山河流域3种不同土地利用方式下紫色土全土及微团聚体(2~0.25,0.25~0.053,0.053~0.002,<0.002mm)对Pb2+吸附解吸特性,并分别运用Langmuir、Freundlich和Temkin方程对等温吸附数据拟合分析。结果表明:不同土地利用方式下,全土及0.25~0.053mm微团聚体最大吸附量关系为林地>旱地>茶园,2~0.25mm微团聚体最大吸附量大小几乎一致,0.053~0.002mm与<0.002mm微团聚体最大吸附量关系为茶园>旱地>林地。不同土地利用方式下全土及微团聚体对Pb2+吸附量均随初始Pb2+质量浓度的增大而增大,均向最小粒径富集,并与土壤有机质、游离氧化铁、CEC含量分布特征一致。等温吸附方程拟合均以Freundlich方程拟合效果最佳,吸附容量的大小关系为:林地>旱地>茶园,且Pb2+吸附均以非专性吸附为主,专性吸附为辅,及部分未知吸附。
Whole soil and micro-aggregates （2~0.25, 0.25~0. 053, 0. 053~0. 002, 〈0. 002 mm） of purple soils under three different land use patterns in Mingshan watershed for Pb2＋ adsorption and desorption char- acteristics were studied by equilibrium liquid adsorption＇s method, the NH4OAC, EDTA as sorbent＇s de- sorption method, and the Langmuir equation, Freundlich equation and Temkin equation were used to analyze and fit the isotherm adsorption data. The results showed that： The order of maximum adsorption capacity of whole soils and particle size of 0.25~0. 053 mm under different land use patterns was： Woodland 〉dry land 〉tea garden, maximum adsorption capacity of 2~0.25 mm micro-aggregates was almost uniform, the maxi- mum adsorption capacity of 0. 053~0. 002 mm and 〈0. 002 mm micro-aggregates was： tea garden 〉dry land 〉woodland. The adsorption capacity of Pb2＋ of whole soils and micro-aggregates increased with increasing the initial concentration of Pb2＋ , and accumulated to the minimum particle size, and was consistency with the characteristic of the soils organic, free iron oxide, CEC content. Freundlich＇s fitting result was optimal by i- sotherm equation. The relationship of the adsorption capacity was：Woodland 〉dry land 〉tea garden. Pb2＋ was adsorbed by non-specific adsorption-based, supplemented by specific adsorption and some unknown way.
出处
《水土保持学报》
CSCD
北大核心
2013年第6期237-243,共7页
Journal of Soil and Water Conservation
基金
四川农业大学学科建设双支计划(2013)
