摘要
以棕壤为研究对象,采用室内模拟冻融环境的方法,研究土壤磷素吸附-解吸行为,采用Langumuir、Freundlich和Temkin方程对吸附过程进行拟合分析,定量研究冻融作用对土壤磷素吸附机制的影响,同时建立土壤磷素解吸量与吸附量关系方程,进一步探讨冻融土壤磷吸附-解吸特性。结果表明,冻融条件下棕壤对磷的吸附规律一致,吸附量均随着平衡溶液中磷浓度增加而逐渐增大,与未冻融土壤相比,冻融后土壤磷等温吸附曲线变得平缓。冻融条件下磷等温吸附曲线用Langmuir方程拟合相关性最好。土壤磷素解吸量与相应最大吸附量符合线性相关。冻融后土壤磷固定吸附量低于未冻融土壤,即冻融过程促进土壤磷素释放,增加了土壤磷流失风险。多次冻融循环对土壤磷吸附-解吸行为影响更为强烈。
A laboratory experiment was conducted to determine the effects of freezing and thawing on phosphorus adsorption desorption characteristic,brown earth was collected and subjected to laboratory tests.Langumuir,Freundlich and Temkin were used to fit equations about the adsorption processing,which can help to quantificationally reflect the effect of freezing and thawing on phosphorus adsorption mechanism.The equations between phosphorus desorption and adsorption were also simulated for further discussion about phosphorus adsorption and desorption characteristics of freezing and thawing earth.The results showed that,the trend of phosphorus adsorption in freezing and thawing treatments was all that the phosphorus adsorption capacity increased with the increasing of phosphorus concentration after freezing and thawing,but compared to the no freeze-thaw treatments samples,phosphorus adsorption curves showed smoother after freeze-thaw cycles.In the condition of freezing and thawing,phosphorus adsorption curves could be fitted by Langmuir equation.Phosphorus desorption capacity and corresponding maximum adsorption capacity adapted to linear correlation.Soil phosphorus fixed adsorption capacity lower after freezing and thawing,in other words,freezing and thawing process promoted the release of soil phosphorus and increased soil phosphorus loss risk.Furthermore,effect of repeated freeze-thaw cycles on phosphorus adsorption and desorption was more intense.
出处
《水土保持学报》
CSCD
北大核心
2012年第2期279-283,共5页
Journal of Soil and Water Conservation
基金
国家自然科学基金项目(41071183
41101256)
关键词
磷
吸附-解吸特性
冻融作用
棕壤
phosphorus
adsorption and desorption character
freeze-thaw
brown earth
