外源腐殖酸对黏质农田土壤Cd活性的影响

Influence of Exogenous Humic Acid on Heavy Metal Cd Activity in Clayey Farmland Soil

为探讨外源腐殖酸对黏质农田土壤Cd活性的影响,选取2种典型腐殖酸,采用淋洗技术,通过测定农田土壤总Cd、DTPA-Cd、MgCl 2-Cd的含量,研究了2种腐殖酸及其淋洗时间对土壤Cd活性的影响。研究结果表明:2种腐殖酸处理后,土壤总Cd含量基本不变,土壤DTPA-Cd含量从0.421 mg/kg降低到0.313 mg/kg,MgCl 2-Cd含量从0.2 mg/kg降低到0.169 mg/kg;淋洗时间从1 d增加到5 d,土壤总Cd含量基本不变,土壤DTPA-Cd含量从0.325 mg/kg降低到0.265 mg/kg,MgCl 2-Cd含量从0.196 mg/kg降低到0.165 mg/kg。因此,2种腐殖酸均对黏质农田土壤镉有一定的去除效果。

The effects of two different extrogenous humic acids on the activity of Cd in clayey farmland were examined by measuring the content of total Cd,DTPA-Cd and MgCl 2-Cd after leaching treatment.After two humic acid treatments,the total content of Cd content in the soil remained unchanged in general,the content of DTPA-Cd decreased from 0.421 mg/kg to 0.313 mg/kg,and the content of MgCl 2-Cd declined from 0.2 mg/kg to 0.169 mg/kg.When leaching time increased from 1 day to 5 days,the total content of Cd also remained unchanged overall,DTPA-Cd decreased from 0.325 mg/kg to 0.265 mg/kg,and MgCl 2-Cd reduced from 0.196 mg/kg to 0.165 mg/kg.In conclusion,both the exogenous humic acids could remove Cd in the soil of clayey farmland.