秸秆炭和沸石对土壤吸附Cd(Ⅱ)的影响  

Effects of Straw Biochar and Zeolite on Adsorption of Cd (Ⅱ) by Soil

作　　者：魏樵 杜立宇[1] 梁成华[1] 周佚群[1] 

机构地区：[1]沈阳农业大学土地与环境学院,沈阳110161

出　　处：《水土保持学报》2014年第2期254-257,261,共5页Journal of Soil and Water Conservation

基　　金：国家自然科学基金(31171997)

摘　　要：为了比较2种类型改良剂对土壤中Cd（Ⅱ）的修复作用，向土壤中添加0．5％和2％的秸秆炭和沸石，培养60d后分析土壤性质的变化，并用一次平衡法研究秸秆炭和沸石对土壤吸附Cd（Ⅱ）的影响。结果表明，添加秸秆炭和沸石均能提高土壤CEC，秸秆炭还可以显著提高土壤pH，0．5％和2％添加量使土壤pH提高0．37和0．66，添加沸石对于土壤pH没有明显提高。等温吸附实验结果表明，添加秸秆炭和沸石均可以增加土壤对Cd（Ⅱ）的吸附量，并且随着添加量的增加而增加，当Cd（Ⅱ）初始浓度为150mg／L时，Cd（Ⅱ）的吸附量提高8．5％～32．5％。随着体系pH的升高，土壤对Cd（Ⅱ）的吸附量增加，在pH较高的体系下，秸秆炭对土壤吸附能力的促进作用更大。解吸实验表明，添加秸秆炭和沸石后土壤Cd（Ⅱ）的解吸量高于对照，说明秸秆炭和沸石提高了土壤对Cd（Ⅱ）的静电吸附量。Freundlich方程更适合拟合添加秸秆炭和沸石后土壤对Cd（Ⅱ）的吸附等温线，R^2值均在0．96以上。从该方程表征吸附容量的参数K，可以看出，秸秆炭促进Cd（Ⅱ）的吸附效果优于沸石，2％添加量的促进效果要优于0．5％添加量。因此，对于辽宁地区的草甸土，秸秆炭对土壤中Cd（Ⅱ）具有更好的修复作用。Soil was incubated with the biochar from straws and the zeolite for 60 days, analyzed the change of the soil properties and then the batch method was used to investigate effects of incorporation of the biochar and the zeolite on adsorption of Cd（ II ）, to compare effect of two types of amendments in Cd（ II ）polluted soils. Results showed that the biochar and the zeolite increased soil CEC, the biochar significantly improved soil pH, 0.5% and 2% amount increased soil pH by 0. 37 and 0.66, soil pH was not improved much by adding the zeolite. Results from adsorption experiments indicated that the incorporation of the biochar and the zeolite enhanced the adsorption of Cd（II ）, and the adsorption also increased with increasing biochar and zeolite added. The adsorption of Cd（ 1I ） increased by 8.5%-32.5%, when the initial concentration of Cd （ 11 ） was 150 mg/L. The adsorption of Cd（ II ）increased with rising pH, the promoting effect of the biochar on the adsorption of Cd（ II ） enhanced with the higher pH. Results obtained from desorption experiment showed that the amount of Cd （ II ）desorbed for the treatments with biochar and zeolite added was greater than that for control, suggesting that the biochar and the zeolite increased the electrostatic adsorption of Cd （ ]I ）by the soils. Freundlich equations could be better used to fit the adsorption isotherms for Cd（ II ）, the r- values were above 0.96. Soil incorporated with biochar had a greater adsorption capacity for Cd（ 11 ）than that incorporated with zeolite as predicted by the parameters of K： in Freundlich equations, promoting effect of 2% added was better than 0.5% added. Therefore, incorporation of the straw biochar on adsorption of Cd （ II ）had better effect of remedying for the meadow soil in Liaoning region.

关 键 词：秸秆炭 沸石 Cd(Ⅱ) PH 吸附解吸 

分 类 号：X131.3[环境科学与工程—环境科学] S153[农业科学—土壤学]