摘要
将堆肥污泥施用于林地能够增加土壤肥力,促进林木增长,具有广阔的应用前景,但污泥中所含重金属进入土壤环境后的积累特征及所引起的生态风险问题亦备受关注。连续5年将污泥堆肥产品施用于林地并对相应林地土壤重金属含量进行了同步监测,采用单因子指数法和潜在生态危害指数法分析评价了污泥堆肥泥质、污泥堆肥不同施用比例以及是否连续施肥等因素对土壤重金属环境风险的影响;并利用相关分析和基于相关系数的聚类分析揭示了土壤重金属来源与施用污泥的关系。结果表明,污泥堆肥中的Hg、Cd、Zn、As、Pb存在较大生态风险;污泥堆肥施用比例为10%和20%时,产生的生态风险较低,而施肥比例为30%和40%时的生态风险较大。施用污泥堆肥后土壤中重金属含量具有一定的累积效应,但均未超过《土壤环境质量标准农用地土壤污染风险管控标准(试行)》(GB 15618-2018)(6.5≤pH≤7.5)限定的含量。土壤重金属累积模型预测结果表明,施肥比例为10%的林地在连续施肥11年后,土壤重金属含量将会超标,即10年内连续施肥较为安全。连续施肥后的林地土壤重金属含量间相关性分析表明,土壤中的重金属并非全部来源于堆肥污泥,大气沉降、降水、土壤母质等因素也影响了土壤的重金属含量。本研究可为林地施用污泥产品提供参考。
The usage of sludge as fertilizers for forest land can improve the soil fertility and the plant growth,but the environmental risks of sludge usage are still unclear due to the relative high concentration of heavy metals in the sludge.Based on the five-year data of heavy metal concentration in the soil after the use of sludge as fertilizers,the single-factor index method and the potential risk hazard index method were used to investigate the effects of sludge properties,sludge dosage and continuous fertilization on the environmental risks of heavy metal in this study.The correlation analysis was also conducted to investigate the relationship between the change of heavy metal in soil and the use of sludge.The results showed that Hg,Cd,Zn,As and Pb in sludge had greater environmental risks,compared to other heavy metals.When the sludge dosage was 10%and 20%,the environmental risks were low.However,the risk to the environment was greater when the sludge dosage was 30%and 40%.The monitoring results showed that the heavy metals in the soil has accumulated but not exceeded Soil Environmental Quality Risk Control Standards for Soil Contamination of Agricultural Land(GB 15618-2018)(6.5≤pH<7.5)in five years.According to the prediction model of soil pollutant accumulation,it showed that the heavy metal concentration in the soil would exceed the standard in the 11th year when the fertilization ratio was 10%,indicating that fertilization was safer in 10 years.Based on the correlation analysis,heavy metals in soil might be affected by various factors such as fertilizer sludge,atmospheric sedimentation,precipitation,and soil parent material.This study can provide a reference for the application of sludge products in forest land to avoid the risk of heavy metals.
作者
王丽霞
杜子文
封莉
孙德智
张立秋
刘永泽
WANG Lixia;DU Ziwen;FENG Li;SUN Dezhi;ZHANG Liqiu;LIU Yongze(College of Environmental Science and Engineering,Beijing Forestry University,Beijing 100083,China;Beijing Key Laboratory of Water Pollution Control Technology,Beijing 100083,China)
出处
《环境工程学报》
CAS
CSCD
北大核心
2021年第3期1092-1102,共11页
Chinese Journal of Environmental Engineering
基金
国家水体污染控制与治理国家科技重大专项(2018ZX07301007)。
关键词
污泥堆肥产品
重金属
风险评价
相关分析
土壤污染物预测模型
sludge composting products
heavy metals
risk assessment
correlation analysis
prediction model of soil pollutant accumulation
作者简介
第一作者:王丽霞(1995-),女,硕士研究生。研究方向:固体废弃物处理处置与资源化利用。E-mail:wanglixia1122@foxmail.com;通信作者:刘永泽(1986-),男,博士,副教授。研究方向:污泥处理处置与资源化、废水处理与资源化等。E-mail:liuyongze@bjfu.edu.cn。
