钝化材料复配对镉污染土壤中镉的固定效果

Study on Effects of Passivation Material on the Frxation of Cd in Cd-contaminated Soil

为探讨钝化材料不同复配处理对Cd污染土壤有效Cd含量的影响,利用土壤培养试验和盆栽试验,采用正交试验设计,研究生物炭、粉煤灰、汉白玉3种钝化材料不同复配处理对土壤pH值和Cd生物有效性的影响。结果表明,3种钝化材料不同复配处理均显著提高了土壤pH值,降低了土壤有效Cd含量。随着时间的延长,大部分处理土壤有效Cd含量呈先降低后逐渐达到平衡的趋势,平衡时间为7~15 d。同时,3种钝化材料的因素主次效应依次表现为汉白玉>生物炭>粉煤灰。添加钝化材料后小白菜可食部位的Cd含量显著降低,降幅为9.10%~24.39%,以小白菜可食部位Cd含量作为评价指标,1.5%生物炭+1.0%汉白玉、1.0%生物炭+1.0%粉煤灰+0.5%汉白玉、1.0%生物炭+0.5%粉煤灰+1.0%汉白玉为最优复配处理。本研究结果为Cd污染土壤钝化修复和作物的安全生产提供了理论依据。

In order to investigate the effect of different compounding treatments on the effective Cd content in Cd contaminated soil,soil incubation experiment,a pot experiment and orthogonal design was conducted to study effects of different compounding treatments of biochar,fly ash and white marble on soil pH and Cd bioavailability.The results showed that the different compounding treatments of the three passivation materials significantly increased the soil pH and reduced the soil effective Cd content.With extension of incubation time,the available Cd concentration decreased first and then gradually reached equilibrium after 7-15 days.Meanwhile,effect of white marble on Cd availability showed the greatest,followed by biochar and fly ash.Furthermore,Cd concentrations in edible parts of Brassica chinensis L decreased by 9.10%~24.39%after adding passivation material.With the evaluation index of Cd concentration in edible parts of Brassica chinensis L,the combination of 1.5%biochar+1.0%white marble,1.0%biochar+1.0%fly ash+0.5%white marble,1.0%biochar+0.5%fly ash+1.0%white marble presented the greatest remediation efficiency.The findings provide a theoretical basis for the remediation of Cd-contaminated soils and also the safe production of crops.