Effect of land use pattern change from paddy soil to vegetable soil on the adsorption-desorption of cadmium by soil aggregates.
The influence of land use change from paddy soil to vegetable soil on the adsorption-desorption behavior of Cd in soil aggregates and the variation in soil properties were investigated. The vegetable soil was characterized by lower pH, organic matter content, cation exchange capacity (CEC), free iron oxides, manganese oxides, and catalase activity and higher urease activity compared with the paddy soil. In the isothermal adsorption and desorption experiments, the adsorption characteristics of Cd of the two soils could be well described by Langmuir and Freundlich equations. The adsorption capacity of vegetable soil decreased 22.72 %, and the desorption rate increased 35 % with respect to paddy soil. Therefore, conversion from paddy to vegetable field can reduce the adsorption ability to Cd of the soil to a certain extent. Both the two soils reached the maximum adsorption capacity and the minimum desorption rate in the <0.002-mm faction. The adsorption capacity of Cd in paddy and vegetable soils exhibited great reliance on the content of CEC. Desorption rate was negatively correlated with the four indicators: organic matter, CEC, free iron oxides, and manganese oxides, and specific adsorption was primarily controlled by soil organic matter and manganese oxides.
College of Environmental Science and Engineering, Hunan University, Changsha, 410082, China.|Key Laboratory of Environment Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, China.
Qiu
Q
Zhang
College of Environmental Science and Engineering, Hunan University, Changsha, 410082, China. lizw@hnu.edu.cn.|Key Laboratory of Environment Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, China. lizw@hnu.edu.cn.
Zhongwu
Z
Li
College of Environmental Science and Engineering, Hunan University, Changsha, 410082, China.|Key Laboratory of Environment Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, China.
Bin
B
Huang
College of Environmental Science and Engineering, Hunan University, Changsha, 410082, China.|Key Laboratory of Environment Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, China.
Ninglin
N
Luo
College of Environmental Science and Engineering, Hunan University, Changsha, 410082, China.|Key Laboratory of Environment Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, China.
Lingzhi
L
Long
College of Environmental Science and Engineering, Hunan University, Changsha, 410082, China.|Key Laboratory of Environment Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, China.
Mei
M
Huang
College of Environmental Science and Engineering, Hunan University, Changsha, 410082, China.|Key Laboratory of Environment Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, China.
Xiuqing
X
Zhai
College of Environmental Science and Engineering, Hunan University, Changsha, 410082, China.|Key Laboratory of Environment Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, China.
Guangming
G
Zeng
D000327:Adsorption; D002104:Cadmium / Q000032:analysis*; D002412:Cations; D006863:Hydrogen-Ion Concentration; D017895:Manganese Compounds; D010087:Oxides; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis*; D014675:Vegetables
D002412:Cations; D017895:Manganese Compounds; D010087:Oxides; D012987:Soil; D012989:Soil Pollutants; D002104:Cadmium; C027424:manganese oxide
Adsorption-desorption behaviors; Aggregates; Cd; Land use change; Paddy soil; Vegetable soil