溶解性有机质对甲草胺在土壤中吸附行为影响

Effect of dissolved organic matter on sorption behavior of alachlor in soil

摘要:

土壤对甲草胺的吸附解吸作用是甲草胺在土壤中迁移转化行为之一,对土壤环境质量变化有重要影响.在松花江沿江3个城市郊区农田(佳木斯(S1)、依兰(S2)和哈尔滨(S3)),采集3种不同理化性质的土壤,采用批量实验方法研究甲草胺在土壤上的吸附-解吸过程以及溶解性有机质对甲草胺吸附-解吸过程的影响.结果表明:溶解性有机质对甲草胺在土壤中的吸附过程有抑制作用,而对解吸过程有促进作用;甲草胺在3种土壤中的吸附-解吸过程符合Freundlich方程(R2>0.858);在3种土壤样品中的吸附量大小依次为S1>S2>S3;甲草胺在3种土壤中吸附-解吸存在滞后现象.

Abstract:

The sorption of alachlor is one of the most important behaviors of transference and transformation of alachlor in soils,and it also plays significant role in the soil environment.Three soil samples were collected from the suburb farmland of Jiamusi(S1),Yilan(S2) and Harbin(S3) along the Songhua River(Northeast,China),and batch experiments were conducted to investigate the effects of dissolved organic matter(DOM) on the adsorption-desorption behavior of alachlor in soil-water system.The results showed that the adsorption capacity of alachlor was suppressed significantly after adding DOM into soil-water system,yet the DOM might accelerate the desorption process of alachlor from soil.The adsorption and desorption isotherms for alachlor in the soil samples were found to fit well with the Freundlich model(R2>0.858)and the order of adsorption capacity of the soil samples was in the order of S1>S2>S3.Hysteresis Index showed that the hysteresis existed in the adsorption-desorption process of alachlor.