设施菜田镉污染修复技术应用研究

A Study on Remediation Technologies for Cadmium Contamination in Greenhouse Vegetable Fields

文章为探讨土壤改良剂与农艺措施对设施蔬菜土壤重金属Cd修复的田间应用效果,根据文献资料和试验结果筛选羟基磷灰石、水稻生物炭、磷酸二氢钾3种改良剂结合深翻农艺措施,2015-2017年筛选、确定设施菜田Cd污染区域,2017年9月进行8种处理比较试验,2018年9月进行优选试验。污染区域筛选结果:超标位点分布不均匀,Cd含量差异大,4号大棚污染点位超标率最高为83.33%,土壤Cd含量平均值最高为0.535 mg/kg,作为8种处理比较试验棚;1号大棚3个超标点集中地块,均值分别为0.530 mg/kg、0.568 mg/kg和0.792 mg/kg作为优选试验棚。比较试验结果:8种处理经过8个月修复,羟基磷灰石+水稻生物炭+深翻处理有效态Cd含量比CK降低32.55%,比修复2个月降低24.96%;磷酸二氢钾+水稻生物炭+深翻处理有效态Cd含量比CK降低47.88%,比修复2个月降低31.00%。优选修复试验结果:羟基磷灰石+水稻生物炭+深翻总Cd含量均值由3个处理最高值0.489 mg/kg,降到0.372 mg/kg,降低23.86%,均值不超标;与CK比较有效态Cd含量呈下降趋势,修复8个月比对照降低10.71%,3个处理有效态Cd均值最低0.133 mg/kg;与CK比较分别降低豆角地上植株Cd含量、富集系数和转运系数15.86%、23.68%和25.77%,是较好的Cd污染设施菜田修复技术。

Based on the literature and experimental results,three kinds of amendments,namely,rice biochar,hydroxyapatite and potassium dihydrogen phosphate(KHPO),and deeper ploughing were selected to evaluate the field application effect of soil amendments and agronomic measures on the remediation of Cd contamination in greenhouses.Cd-contaminated greenhouse screening was conducted from 2015 to 2017.In September 2017,comparative tests of eight treatments were performed in September 2017,and a selective test was performed in September 2018.The results of the screening of contaminated areas indicated that the distributions of over-standard sites and Cd content were significantly different.Greenhouse No.4,in which the highest over-standard rate was 83.33%and the average content of Cd in soil was 0.535 mg/kg,was used as a comparative test experimental site for eight treatments.Greenhouse No.1 was selected as the optimum test greenhouse for selective testing,with three plots having average Cd concentrations of 0.530 mg/kg,0.568 mg/kg and0.792 mg/kg.The comparative test results 8 months following treatment showed that the content of available Cd following the treatment of rice biochar+hydroxyapatite+deeper ploughing(treatment T6)was reduced by 32.55%and 24.96%compared to CK(the control)and 2 months following treatment,respectively.The content of available Cd using rice biochar+KHPO+deeper ploughing(treatment T7)treatment decreased by 47.88%and 31.00%compared to CK and 2 months following treatment.The selective test results showed that in rice biochar+hydroxyapatite+deeper ploughing:the total Cd content of decreased from 0.489 mg/kg to 0.372 mg/kg(23.86%lower),ompared with CK,the mean content of available Cd decreased by10.71%after 8 months,which was the lowest available Cd measured(0.133 mg/kg).In addition,the bean plant Cd content,bioconcentration factor(BCF)and translocation coefficient(TF)decreased by 15.86%,23.68%and 25.77%,respectively.Rice biochar+hydroxyapatite+deeper ploughing is a favoured technology for the remediation of Cd-contaminated protected vegetable fields.