常用矿物质材料对镉钝化稳定性研究

The Passivation Stability of Cadmium by Applying Common Mineral Materials

为研究常用矿物质钝化剂对农田土壤中镉钝化的长期稳定性,本文以石灰、海泡石、彭润土、麦饭石、生物质为原料复配成4种钝化剂,采用大田试验方法,按2250 kg/hm2一次施用钝化剂,连续2年种植四季水稻,比较土壤有效态镉及稻米中镉含量变化情况。试验结果显示:4种钝化剂对土壤镉的钝化稳定性依次为P(彭润土+生物炭)>H(海泡石+生物炭)>M(麦饭石+生物炭)>S(石灰+生物炭),其中,钝化剂P对农田土壤pH影响较持久,且施用钝化剂P的大田种植四季水稻稻米镉含量均<0.2 mg/kg,所以,钝化剂P对土壤镉的钝化长期稳定性较好。研究结果可为农田重金属污染修复以及钝化剂的实际应用提供理论依据。

To study the long-term stability of cadmium passivation in farmland soil by applying mineral passivators,in this paper,four passivators were prepared from lime,sepiolite,bentonite,maifanite and biochar,and the field test method was used to apply passivators once at the rate of 2250 kg/hm2 to planting early rice and late rice for two consecutive years,to compare the changes of available cadmium in soil and the content of cadmium in rice.The results showed that the passivation stability of the four passivators on soil cadmium was P>H>M>S.Among them,the influence of passivator P on the pH of farmland soil was more lasting,and the cadmium content of rice in the field applied with passivator P was<0.2 mg/kg,so passivator P had better long term stability of soil cadmium passivation.The results could provide a theoretical basis for the remediation of heavy metal polluted farmland and the practical application of passivators.