作 者：
宫春艳;吴英;徐明岗;周世伟;吕粉桃;陈苗苗
单 位：
中国农业科学院农业资源与农业区划研究所;东北农业大学资源与环境学院
摘 要：
采用等温吸附法研究了红壤和褐土磷的吸附特性,并分析了磷吸附后镉离子的吸附-解吸特征。结果表明,在外源磷浓度0～64mg·L-1范围内,供试土壤磷吸附量均随平衡液中磷浓度的升高而增加,吸附等温线符合Langmuir方程,红壤对磷的最大吸附量及吸附反应常数(K)均高于褐土。吸附磷后在镉添加0～5mg·L-1范围内对镉离子吸附的影响两种土壤表现一致,即镉离子的吸附量随平衡溶液中镉的浓度的升高而增加,二者呈极显著线性相关。但磷吸附量的不同对镉离子的吸附产生一定的影响,表现为低磷抑制、高磷促进镉离子的吸附。当吸附磷的量红壤小于40mg·kg-1、褐土小于37mg·kg-1时,镉离子的吸附量随磷吸附量的增加而降低,与不施磷处理相比吸附率平均降低了16%和10%左右;当吸附磷的量红壤大于79mg·kg-1、褐土大于70mg·kg-1时,镉离子的吸附量随磷吸附量的增加而升高,与对照相比吸附率平均升高了11%和6%左右。吸附磷酸根后,在镉离子的吸附量小于10mg·kg-1时,红壤镉离子的解吸率表现为低磷促进、高磷抑制解吸,而褐土磷的吸附对镉离子解吸率的影响不显著。
译 名：
Phosphate Adsorption and Its Effect on Adsorption-Desorption of Cadmium in Red Soil and Cinnamon Soil
作 者：
GONG Chun-yan1,2, WU Ying1,3, XU Ming-gang2, ZHOU Shi-wei2, LV Fen-tao2, CHEN Miao-miao2 (1. Resources and Environmental Sciences College, Northeast Agricultural University, Harbin 150030, China; 2. Institute of Agricultural Resource and Regional Planning, Chinese Academy of Agriculture Sciences, Key Laboratory of Plant Nutrition Cycling, Ministry of Agriculture, Beijing 100081, China; 3. Institute of Soil and Fertilizer, Heilongjiang Academy of Agricultural Sciences, Harbin 150086, China)
关键词：
phosphate; cadmium; red soil; cinnamon soil; adsorption-desorption
摘 要：
A batch experiment by using isotherm adsorption method was conducted to study phosphate adsorption and its effect on adsorption-desorption of cadmium in red soil and cinnamon soil. The results indicated that adsorption the amount of phosphate increased with increasing concentration of phosphate in equilibrium solution with phosphate application levels ranging from 0 to 64 mg·L-1 in two soils. The relationship could be described by Langmuir or Freundlich equation. The maxmium amount of adsorbed phosphate and constants of adsorption(K)in red soil were higher than those in cinnamon soil. After phosphate adsorption, the adsorption amount of cadmium ion increased with increasing concentration of cadmium ion in equilibrium solution in two soils after adding cadmium ion from 0 to 5 mg·L-1, which fitted a linear equation with significantly correlation at P<0.01. However, the changes of phosphate adsorption resulted in difference of adsorption of cadmium ion, showing that the adsorption of cadmium ion was enhanced by higher phosphate and inhibited by lower phosphate concentration. The cadmium ion sorption decreased with an increase of phosphate sorption when adsorbed phosphate was less than 40 mg·kg-1 in red soil and 37 mg·kg-1 in cinnamon soil, the average of adsorption ratio declined by 16% and 10%, respectively, as compared to no phosphate application. Moreover, cadmium ion sorption increased with increasing phosphate sorption when adsorbed phosphate was higher than 79 mg·kg-1 in red soil and 70 mg·kg-1 in cinnamon soil. The adsorption ratio increased by 11% and 6% on an average, respectively as compared with control. Desorption of cadmium ion from red soil and cinnamon soil increased with increasing adsorption of cadmium ion, however, the desorption amount of cadmium ion showed different dynamics for the two soils after phosphate adsorption. When adsorption amount of cadmium ion was less than 10 mg·kg-1, the desorption ratio of cadmium ion was reduced at higher phosphate concentration in red soil, but no significant difference was observed within experiment concentrations of phosphate in cinnamon soil.
