复合钝化剂对污灌区镉污染农田土壤的钝化效果研究

摘要

利用盆栽试验研究由海泡石、生物炭、腐殖酸组成的复合钝化剂以不同配比(0,0.1%,0.3%和0.5%)施入污灌区土壤后,通过进行土壤pH、有机质对土壤重金属Cd有效态的相关分析,测定小白菜、生菜、菠菜3种蔬菜的生物量及亚细胞中的Cd分布,揭示其作用机制和修复效果.结果表明:①加入复合钝化剂后,土壤有机质含量升高,有效态Cd含量降低,蔬菜内Cd含量降低;②复合钝化剂施用比相同时,土壤有机质含量为菠菜>生菜>小白菜;施用比为0.3%时,种植菠菜的土壤有机质含量最高,菠菜的生物量增幅最大;③施用比为0.3%时,蔬菜可溶性组分中Cd含量增幅最大,细胞原生质体内Cd浓度显著降低,保证植物正常生理代谢.因此,施加0.3%的复合钝化剂并种植菠菜,是降低污灌区土壤中有效态Cd含量的最佳选择.%In order to reveal the action mechanism and repair effect of multi-passivators,the pot experiment was conducted to study the effects of different passivating agents composed of sepiolite,biochar and humic acid (0,0.1%,0.3% and 0.5%)on the soil irrigated area,through the correlation analysis of soil pH,organic content and soil Cd availability,elucidated the subcellular distribution of Cd in the different vegetables'' blades.The results indicated that:After adding the multi-passivators,the content of soil organic matter increased,the content of available Cd decreased,the content of Cd in vegetables decreased;The content of soil organic matter was the highest in spinach>lettuce>Chinese cabbage.When the application ratio was 0.3%,the organic matter content of spinach was the highest,and the biomass of spinach was the biggest;When the application ratio was 0.3%,the Cd content in the soluble components of vegetables increased the most,the Cd concentration in the protoplasts of the plants decreased significantly,and the normal physiological metabolism of plants was ensured.Therefore,the application of 0.3% multi-passivators and planting spinach,is to reduce the soil available Cd in the sewage irrigation area the best choice.