Cd污染稻田修复体系实施效果

Application Effect of Remediation System of Rice Field Contaminated by Cd

本研究选取超级腐殖质、矿物质稳定剂、复合有机肥和普通有机肥4种土壤改良剂,结合科学的灌溉管理方法和叶面阻控技术,对湖南省长沙市镉污染稻田进行修复效果验证。结果表明,土壤改良剂的加入和科学的田间管理可以显著降低稻谷中Cd浓度,甚至可以有效控制中度污染区域稻谷中Cd浓度,使之达到国家食品安全标准。其对稻谷Cd浓度的削减效果由高到低排序依次为超级腐殖质>复合有机肥>矿物质稳定剂>普通有机肥。但所有改良剂对稻谷Cd浓度的削减效果均不及生石灰。对于重度污染区域,土壤改良和科学的田间管理虽然能够较大地削减稻谷中的Cd,但是无法达到食品安全要求,建议对重污染区进行种植结构调整,不再作为水稻种植用地。

Four types of soil amendments including super humic matter,mineral stabilizer,compound organic matter and common organic fertilizer were selected, combining scientific irrigation management system and leaf transportation impediment control technology, the application effect of remediation system of Cd contaminated rice field of Changsha City in Hunan Province were tested in this paper. The results showed that the addition of soil amendments and scientific field management could significantly reduce the concentration of Cd in rice,and even could effectively control the concentration of Cd in paddy soil of moderate pollution area,which could meet the national food safety standards. The Cd control ability of these four amendments followed the sequence：super humic matter〉compound organic matter〉mineral stabilizer〉common organic fertilizer. However,the Cd reduction effects of all soil amendments were poorer than the application effect of lime. The scientific management system was effective for moderate contaminated fields, but the C d concentration in rice still couldn＇t meet the requirement of the food safety standards. Therefore,it＇s suggested to change the farming structure instead of planting rice.