新农药HW-02在土壤中的吸附

采用振荡平衡法研究了新型除草剂HW-02在5种不同土壤中的吸附特性. 结果表明:土壤对HW-02的吸附性强；HW-02在黑钙土、白浆土、草甸土、砂性土和黏壤土等5种土壤中的吸附可用Freundlich等温式较好地描述，其吸附系数(K_F)分别为332.65，103.32，672.97，577.96和289.60，吸附自由能变绝对值(ΔG)分别为16.55，22.73，18.32，18.48和22.86 kJ/mol，说明HW-02在土壤中的吸附以物理吸附为主；HW-02在5种土壤中的有机质吸附常数(K_OM)为796.57～10 197.18，说明其在土壤中迁移性很弱. HW-02在土壤中的吸附系数与土壤w(有机质)，pH和w(黏粒)相关性较好，而与阳离子交换量(CEC)的相关性差，说明土壤w(有机质)，w(黏粒)和pH是影响HW-02在土壤中吸附的主要因素. 

Adsorption of Novel Herbicide HW-02 on Soils

The adsorption behavior of the herbicide HW-02 on five soils was investigated in the laboratory by using batch equilibration technique. The experimental results showed that HW-02 had a strong adsorption to the soils. Adsorption isotherms of HW-02 on the soils could be described well by the Freundlich equation. Adsorption coefficients (K_F) of HW-02 on soils of Chernozem, Ablic soil, Meadow soil, Arenosols clay and clay were 332.65, 103.32, 672.97, 577.96 and 289.60, respectively. The K_OM values ranged from 796.57 to 10,197.18. This suggested that HW-02 has very weak mobility in the soils according to McCall's classification scheme. Adsorption free energy (ΔG) of HW-02 on Chernozem, Ablic soil, Meadow soil, Arenosols clay and clay were 16.55, 22.73, 18.32, 18.48 and 22.86 kJ/mol, respectively. This indicates that the HW-02 adsorption is dominated by physical adsorption. There were good correlations between adsorption coefficients (K_F) of herbicide HW-02 on the five different kinds of soils and the soil properties, such as organic matter, pH and clay content. A poor correlation was found between K_F and cation exchange content of the soils. This indicates that organicmatter,pH and clay content are the predominate factors influencing adsorption of HW-02 on the soils studied.