不同生物质炭和矿物钝化材料对镉污染稻田土壤的修复研究

Remediation of Cd contaminated paddy soil using different kinds of biochar and mineral materials: a field trial

选择常见的3种秸秆生物质炭(水稻生物质炭、小麦生物质炭和玉米生物质炭)和3种矿物钝化材料(钙镁磷肥、磷矿粉和硅肥),在田间开展不同施用量对Cd污染稻田土壤的钝化修复试验,比较不同材料的修复效果,并对其使用成本进行评估。结果表明,除高用量硅肥处理降低了水稻产量外,其他钝化材料对水稻产量没有显著影响;玉米生物质炭和钙镁磷肥处理的土壤pH升高幅度和对土壤有效态Cd含量的降低幅度均大于其他钝化材料;钙镁磷肥降低糙米Cd含量的效果最好,中、高施用量处理糙米Cd含量分别降低至0.179 mg/kg和0.137 mg/kg,下降幅度达45.9%和58.5%;3种生物质炭材料中仅高施用量水稻生物质炭可显著降低糙米Cd含量;从钝化材料的使用成本来看,生物质炭类材料明显高于矿物钝化材料,综合不同钝化材料的修复效果和使用成本,钙镁磷肥是一种值得推荐的钝化修复材料。

In order to study the remediation effect of different immobilization materials,three kinds of straw biochar （rice biochar-SD,wheat biochar-XM and corn biochar-YM） and three kinds of mineral materials （calciummagnesium phosphate-GM,phosphate rock powder-P,silicon fertilizer-GF） were selected and applied in the field of cadmium contaminated paddy soil. The results showed that different immobilization materials had no significant effect on rice yield except for high dosage GF treatment decreased rice yield. The increcse in soil p H and the decrease of soil available Cd content in YM and GM treatments were greater than those in other treatments. The decreased in Cd content in brown rice with high dosage GM treatment was 45.9%,respectively 58.5% （from 0.179 mg/kg to 0.137 mg/kg）. In three kinds of biochar treatments,treatment with high dosage SD can significantly reduce the Cd content of brown rice. The use cost of biochar was obviously higher than that of mineral materials. Considering remediation effect and use cost of different materials,GM is a highly recommended immobilization material,and the use of biochar as immobilization material still need to consider some factors such as costs and remediation efficiency.