摘要
采用田间试验研究了施加不同用量(2、4、8、16 t·hm^(-2))的脱硫石膏对紫色水稻土重金属(Cd、Pb、Zn、Cu)全量、形态分布和水稻重金属吸收及分配的影响,为脱硫石膏农用的安全性提供科学依据。结果表明:施加脱硫石膏后,土壤Pb全量较对照显著增加14.00%~68.77%(P<0.05),脱硫石膏用量低于4 t·hm^(-2)时土壤Cd全量与对照差异不显著,超过该用量时Cd全量较对照显著增加16.28%~19.94%,而土壤Zn、Cu全量与对照无显著差异,且土壤重金属全量均符合《土壤环境质量标准》(GB 15618—1995);同时施加脱硫石膏后,土壤中Cd可交换态占比降低,残渣态占比增高,并促进Pb的可交换态向有机结合态和铁锰氧化态转化,Zn铁锰氧化态占比增高,对Cu的赋存形态无明显影响;脱硫石膏处理组水稻根、茎叶和籽粒中重金属含量有不同程度的降低,水稻根、茎叶及籽粒对Cd、Pb的富集系数下降,且籽粒中Cd、Pb、Zn、Cu含量均符合我国《食品安全国家标准食品中污染物限量》(GB 2762—2012)。水稻各部分对Cd、Pb的积累与其可交换态、碳酸盐结合态、铁锰氧化态和有机结合态含量均呈正相关,其中籽粒Cd含量与可交换态Cd含量呈极显著正相关(P<0.01)。在脱硫石膏2～16 t·hm^(-2)用量范围内,稻田土壤Cd、Pb全量有所增加,Zn、Cu全量无变化,Cd、Pb赋存形态向稳定态转化,水稻各部分Cd、Pb、Zn、Cu含量有不同程度降低,脱硫石膏可在水稻田安全利用。
A plot experiment was performed to investigate the effects of desulfurized gypsum on heavy metal(Cd,Pb,Zn,Cu)accumulation in soil,speciation,rice absorption and redistribution in purple paddy soil.The results showed that after desulfurated gypsum application,the total amount of Pb in soil increased significantly by 14.00%~68.77%(P<0.05).While with less than 4 t·hm-2 desulfurized gypsum application,the total amount of Cd in soil was not significantly different from that of control.With over 4 t·hm-2 application,the total amount of Cd increased significantly by 16.28%~19.94%compared with that of control(P<0.05).However,the total amount of Zn and Cu had no significant difference with that of control,and the total amount of heavy metals in soil met the Soil Environmental Quality Standard(GB 15618-1995).Meanwhile,after application of desulfurized gypsum,the proportion of exchangeable Cd in soil decreased and the proportion of residual Cd increased,which also promoted the transformation of exchangeable Pb to organic-bound and ferromanganese oxidation Pb.And the proportion of Zn ferromanganese oxidation state increased,while there was no obvious effect on the occurrence form of Cu.The content of heavy metals in roots,stems,and grains had different reducing rates with the increase of the desulfurized gypsum treatment.The enrichment coefficients of Cd and Pb in roots,stems,and grains decreased,and the contents of Cd,Pb,Zn and Cu of rice met national limit index(GB 2762-2012).Accumulation of Cd and Pb in rice was positively correlated with exchangeable,carbonate bound,ferromanganese oxidation and organic bound,and grain Cd content was positively correlated with exchangeable Cd significantly(P<0.01).Gypsum could be used safely in paddy fields within the range of 2~16 t·hm-2.The contents of Cd and Pb in paddy soils increased,while the contents of Zn and Cu showed no change.The form of Cd and Pb varied to stable state.Cd,Pb,Zn,Cu contents decreased to varying degrees.
作者
胡翔宇
向秋洁
罗伯林
尚二凤
木志坚
HU Xiang-yu;XIANG Qiu-jie;LUO Bo-lin;SHANG Er-feng;MU Zhi-jian(College of Resources and Environment,Southwest University,Chongqing 400716,China;Chongqing Key Laboratory of Agricultural Resources and Environment,Chongqing 400716,China;Key Laboratory of the Eco-environments in Three Gorges Reservoir Region,Ministry of Education,Chongqing 400716,China)
出处
《农业资源与环境学报》
CAS
北大核心
2018年第5期459-466,共8页
Journal of Agricultural Resources and Environment
基金
国家自然科学基金项目(41371211)
关键词
脱硫石膏
紫色土
重金属
形态
水稻
富集系数
desulfurized gypsum
purple soil
heavy metal
morphology
paddy rice
enrichment coefficient
