农业环境科学学报2017，Vol.36Issue(10)：2000-2006,7.DOI:10.11654/jaes.2017-0245
硅对不同pH水田土壤镉吸附热力学特征的影响
Effect of silicon additives on the adsorption thermodynamics of cadmium in paddy soil with different pH levels
摘要
Abstract
In previous studies,most silicon additives for soil were alkaline compounds that increased soil pH and introduced potential interfering ions.In this study,the effect of silicon on the adsorption thermodynamics of Cd in paddy soil with different pH levels was investigated through adsorption isotherm experiments.HNO3 was used to neutralize the alkalinity of Na2SiO3,while different concentrations of NO3-and Na+ between treatments were balanced with NaNO3.The results showed that Freundlich adsorption models could fit well to simulate the Cd adsorption characteristics at three different temperatures(25 ℃,35 ℃,45 ℃) in two types of soils.Cd adsorption was restricted in alkaline soil but enhanced in acidic soil at different temperatures after the addition of silicon.Thermodynamic parameters showed that the adsorption processes were endothermic and spontaneous,and entropy increased.At increased levels of silicon,△G increased and △H and △S decreased in alkaline soil,whereas △G decreased,and △Hand △S increased in acidic soil.This phenomenon indicates that the spontaneity of Cd adsorption decreased in alkaline soil,but increased in acidic soil,with the addition of silicon.关键词
硅/镉/pH/水田土壤/吸附热力学Key words
silicon/cadmium/pH/paddy soil/adsorption thermodynamics分类
资源环境引用本文复制引用
赵玉婷,王耀晶,应博,杨丹,何娜,刘鸣达..硅对不同pH水田土壤镉吸附热力学特征的影响[J].农业环境科学学报,2017,36(10):2000-2006,7.基金项目
国家自然科学基金项目(31040070,41371306)The National Natural Science Foundation of China(31040070,41371306) （31040070,41371306）
