摘要
该文探讨沼液还田后对土壤和马铃薯重金属含量的影响,以实现沼液的无害化利用。于2018年1-5月采用田间试验,设置10个沼液施用量处理,以清水和常规化肥为对照。采集对应点位的马铃薯及土壤样品,测定重金属(Cu、Zn、Pb、Cr、Cd)含量,并对重金属含量、土壤-马铃薯污染状况及人体健康风险进行分析讨论。结果表明:(1)施用沼液后土壤重金属Cu、Zn、Pb、Cr、Cd均值为33.5、136.6、25.5、63.9、0.266 mg/kg,马铃薯重金属均值为1.34、4.07、0.022、0.055、0.018 mg/kg,均低于国家标准值,但沼液处理的土壤重金属值均高于试验前土壤测定值;(2)内梅罗污染指数表明,当沼液施用量>76 t/hm^2时,污染指数处于警戒级。潜在生态风险指数表明一季种植中施用沼液的土壤重金属潜在风险较低。马铃薯重金属富集能力排序为Cd>Cu>Zn>Pb>Cr,相关系数表明马铃薯和土壤重金属Cu、Zn、Cd呈显著正相关。结合内梅罗污染指数、潜在生态风险指数、富集系数与相关系数表明,重金属Cd的贡献最大,有必要对沼液中的Cd进行防控;(3)施用沼液后,土壤-马铃薯系统的综合质量指数最大值为0.682,均值为0.656,状况良好。沼液处理组成人、儿童重金属暴露风险的最大值为0.520、0.710,均值为0.461、0.630,健康风险程度低,沼液种植的马铃薯可安全食用。综上,在一季种植中施用一定量的沼液进行调控对土壤和马铃薯重金属的污染影响不明显,可安全利用。
The effects of biogas slurry returning on the soil and potato heavy metal content were discussed to realize the harmless utilization of biogas slurry.Field experiments were conducted from January to May,2018.Ten gradients of biogas slurry application were set up,with clear water and conventional fertilizers as control.Potatoes and soil samples were collected at corresponding locations to determine the contents of heavy metals(Cu,Zn,Pb,Cr,Cd).Then the concentration of heavy metals,the contamination of soil-potato and the associated human health risk were comprehensively analyzed.The results showed that average values of Cu,Zn,Pb,Cr and Cd in soil treated with biogas slurry in one season were 33.5,136.6,25.5,63.9 and 0.266 mg/kg,and those in potato were 1.34,4.07,0.022,0.055 and 0.018 mg/kg,which were lower than the corresponding national standards,but the values of heavy metals in soil treated with biogas slurry were higher than those measured before the experiment.Nemero pollution index indicates that when the application amount of biogas slurry was more than 76 t/hm^2,it shows that the pollution index was at alert level.Potential ecological risk index indicated that the potential risk of heavy metals in soil was low after application of biogas slurry.The order of heavy metal enrichment ability of potato was Cd>Cu>Zn>Pb>Cr,and the correlation coefficient indicates that there was a significant positive correlation between Cu,Zn and Cd in potato and soil heavy metals.Combined with Nemero pollution index,potential ecological risk index,bio-concentration factor and correlation coefficient,it was found that heavy metal Cd contributed the most,and it was necessary to prevent and control Cd in biogas slurry.In field application of the biogas slurry,the maximum comprehensive quality index of soil-potato system was 0.682,the average value was 0.656,which was in good condition.The maximum exposure risk of adults and children to heavy metals in the biogas slurry treatment group was 0.520 and 0.710,the average value was 0.461 and 0.630.The associated human health risk was low.The potato planted by biogas slurry could be safely eaten.In summary,the application of a certain amount of biogas slurry in a season of planting had no obvious effect on the pollution of heavy metals in soil and potato,so it could be used safely.
作者
罗伟
赖星
伍钧
刘永富
李炎
许瑶
孟晓霞
LUO Wei;LAI Xing;WU Jun;LIU Yongfu;LI Yan;XU Yao;MENG Xiaoxia(College of Environmental Science,Sichuan Agricultural University,Chengdu 611130,China;Sichuan Academy of Environmental Sciences,Chengdu 610041,China)
出处
《环境科学与技术》
CAS
CSCD
北大核心
2019年第10期160-168,共9页
Environmental Science & Technology
基金
四川省科技支撑计划项目（2014NZ0045）
关键词
沼液
土壤
马铃薯
重金属
健康风险
biogas slurry
soil
potato
heavy metal
health risk
