羟基磷灰石与秸秆生物炭对青菜镉积累的钝化效应  

Effect of hydroxyapatite and straw biochar on reducing cadmium accumulation in vegetables

作　　者：童欣 刘欣[1] 陈志怀 李楠 张婷婷[1] 郭豪华 岳慧 臧若翔 罗小三[1] TONG Xin;LIU Xin;CHEN Zhi-huai;LI Nan;ZHANG Ting-ting;GUO Hao-hua;YUE Hui;ZANG Ruo-xiang;LUO Xiao-san(Department of Agricultural Resources and Environment,Nanjing University of Information Science and Technology,Nanjing 210044,China;Xinyi Cultivated Land Quality Protection Station of Jiangsu Province,Xuzhou 221400,China)

机构地区：[1]南京信息工程大学农业资源与环境系,江苏南京210044 [2]江苏省新沂市耕地质量保护站,江苏徐州221400

出　　处：《环境生态学》2024年第7期75-81,共7页Environmental Ecology

基　　金：中央土壤污染防治专项资金项目(新集采单2021-1468)资助。

摘　　要：农田重金属污染通过食物链危害人体健康,对土壤改良实现安全利用和保障农产品质量安全成为重要现实需求。本研究实地采集苏北Cd污染农田土壤分别进行模拟培养和温室蔬菜盆栽试验,探讨施加不同用量的羟基磷灰石(HAP,1%、2%)、水稻秸秆生物炭(BC,1%、2%)及其组合施用(0.5%HAP+0.5%BC、1%HAP+1%BC)对土壤Cd活性的钝化效率和降低青菜Cd吸收的效果并分析其作用机制。青菜盆栽试验表明,不同钝化剂处理均提高了叶片的净光合速率,生物量增加3.78%~124%,青菜Cd含量与土壤有效态Cd浓度分别降低16.1%~81.7%、15.8%~69.9%;40 d土壤培养试验后,各钝化剂对有效态Cd的降幅达28.9%~87.6%,主要机理是土壤pH显著提高了0.38~0.98个单位、Cd残渣态含量增加19.5%~37.0%、酸溶态含量减少21.1%~25.6%。可见,2种类型的钝化剂均主要通过降低土壤中Cd的化学活性和植物有效性来阻控其被蔬菜吸收积累,而在同等用量下的酸性污染土壤中,无机型材料HAP对提高蔬菜生物量和降低Cd吸收效果最佳且起效更快,其次则是HAP+BC复配的无机-有机复合型改良剂,但有机型材料BC则效果偏弱且起效慢,需要协同施用HAP提升钝化效率。The contamination of farmland with heavy metals poses a significant threat to human health through the food chain,necessitating the enhancement of soil quality for safe agricultural practices and the assurance of the quality of agricultural products.Soil samples were obtained from Cd-contaminated farmland in northern Jiangsu for simulated incubation and greenhouse vegetable pot experiments.To investigate the passivation efficiency of various dosages of hydroxyapatite(HAP,1%,2%),rice straw biochar(BC,1%,2%),and their combined applications(0.5%HAP+0.5%BC,1%HAP+1%BC)were compared for their efficacy in immobilizing soil Cd and diminishing Cd absorption by vegetables.The study elucidated these effects through chemical speciation analysis and the plant physiological responses.Pot experiments with vegetables revealed that all immobilizing amendments increased the net photosynthetic rate of leaves,resulting in a biomass increase ranging from 3.78%to 124%.Furthermore,the Cd accumulation in vegetables and the concentration of available Cd in the soil were reduced by 16.1%to 81.7%and 15.8%to 69.9%,respectively.Notably,Cd content in vegetables was decreased by 69.9%,66.4%and 18.7%under 2%HAP,1%HAP+1%BC and 2%BC amendments,respectively.In the 40-day soil incubation experiment,available Cd reductions varied from 28.9%to 87.6%among different amendments.The principal mechanisms included an increase in soil pH by 0.38 to 0.98 units,the residual content of Cd increased by 19.5%to 37.0%,and the acid-soluble content of Cd decreased by 21.1%to 25.6%.Overall,all types of amendments effectively regulated the absorption and accumulation of Cd in vegetables by diminishing its chemical activity and phyto-availability in the soil.In acidic-polluted soils,at an equivalent dosage,inorganic amendment HAP proved to be the most effective in enhancing vegetable biomass and reducing Cd uptake,followed by the inorganic-organic composite amendment of HAP+BC.However,the organic amendment BC exhibited weaker and slower effects,necessitating co-applic

关 键 词：重金属污染 钝化剂 化学形态 植物有效性 农产品安全 

分 类 号：X53[环境科学与工程—环境工程]