红壤中非吸附性离子水平运移特征试验研究

Experimental Study on Horizontal Transport of Non-adsorbing Anion in Red Soil

以南方第四纪红壤为研究对象,以KBr溶液为示踪剂,采用水平土柱入渗法研究不同土壤前期含水量和入渗液浓度条件下非吸附性离子溴在红壤中的水平运移特征。结果表明,浓度梯度和水势梯度分别在水平入渗的初期和后期阶段起主导作用;Br-整体水平运移速率与入渗液浓度之间基本存在正相关关系,土壤前期含水量的不同,入渗液浓度对溴离子运移速率的影响程度各异;土壤前期含水量的提高促进了Br-的运移,同时也揭示了当浓度梯度一定时,水势梯度的变化直接影响湿润锋及Br-的运移。

Taking quaternary red soil as research object and KBr as tracer,the transport processes of bromine in red soil were studied by using horizontal soil column and adjusting antecedent moisture content and bromide infiltration concentration.The results show that concentration gradient and water potential gradient respectively play a leading role in prior and late stages of transport.There was a positive correction between average velocity and infiltration solute concentration.Besides,the effect degree of infiltration solute concentration is different at the different antecedent moisture content,and the increased antecedent moisture content accelerated the transport of Br-.Simultaneity,the change of water potential gradient effected directly moisture front and Br-transport.