摘要
为研究堆存粉煤灰中污染物释放特征及其环境影响,以陕西榆林某电厂循环流化床粉煤灰为研究对象,探究了其在降雨影响下,污染物Cr、Cu、As、Se、Mo、Ba、F^(−)、COD、TN释放规律及其环境风险。结果表明,浸出过程中污染物浸出率为Mo>Se>F^(−)>TN>As>Cu>Ba>COD>Cr,Mo浸出率最高(77.74%),Cr最低,主要以残渣态赋存有关。淋溶过程中,F^(-)浓度呈先下降再上升后趋稳的规律,其余污染物均大致随时间逐渐降低后趋稳;不同pH条件下,Cr、Cu、As、Ba在pH=3,Se、COD、TN在pH=5,Mo、F^(−)在pH=7时释放量最高;动力学分析表明,Cr、Cu、Se、Mo、Ba的释放符合二级动力学方程,F^(−)、COD、TN符合Freundlich方程,As在pH=3时符合抛物线方程,在pH=5、7时符合Freundlich方程。根据拟合结果对污染物释放量进行预测,Se、F在5年内可能会超出当地土壤背景值。风险评估结果表明,浸出液中As、Se、Mo、F^(−)、COD、TN均超出地表水或地下水体Ⅲ类标准限值;RAC评估表明,微量元素风险依次为Se>As>Mo>Cu>Ba>Cr,Se为中等风险,其余为低风险,潜在生态风险评估表明As、Cu、Cr的潜在生态风险为轻微污染。两种方法对As、Cu、Cr的风险大小评价结果一致,均为As>Cu>Cr。本研究可为堆存粉煤灰的污染物释放与环境风险管理提供数据参考。
To investigate the release characteristics and environmental impacts of pollutants from stockpiled coal fly ash,this study focused on the circulating fluidized bed coal fly ash from a power plant in Yulin,Shaanxi Province.The research explored the release patterns and environmental risks of Cr,Cu,As,Se,Mo,Ba,F^(−),COD,and TN under the influence of rainfall.The results indicated that,the leaching rates of pollutants during the leaching process followed the order was Mo>Se>F^(−)>TN>As>Cu>Ba>COD>Cr.Mo had the highest release rate(77.74%)and Cr the lowest,which was related to its predominant as residual species in the coal fly ash.During the column leaching process,the concentration of F^(−)initially decreased,then increased,and eventually stabilized,while the concentrations of other pollutants generally decrease over time before stabilizing.Under different pH conditions,the release amounts of Cr,Cu,As,and Ba was highest at pH=3,Se,COD,and TN at pH=5,and Mo and F^(−)at pH=7.Kinetic analysis showed that the release of Cr,Cu,Se,Mo,and Ba followed a second-order kinetic model,while F^(−),COD,and TN fitted the Freundlich model.As followed a parabolic model at pH=3 and the Freundlich model at pH=5 and 7.Based on model fits,Se and F-were predicted to exceed local soil background levels within five years.Risk assessment results indicated that the concentrations of As,Se,Mo,F^(−),COD,and TN in the leachate exceeded the ClassⅢstandard limits for surface water and groundwater.RAC evaluation showed that the risk of trace elements followed the order was Se>As>Mo>Cu>Ba>Cr,with Se posing a medium risk and the others a low risk.Potential ecological risk assessment indicated that As,Cu,and Cr pose minor ecological risks.Both methods showed consistent risk rankings for As,Cu,and Cr,with As>Cu>Cr.These findings provide a reference for understanding pollutants release and managing the environmental risks associated with coal fly ash.
作者
卢永琦
肖嘉宁
迭庆杞
徐思琪
黄瑞潇
孔祥蕊
杨玉飞
LU Yongqi;XIAO Jianing;DIE Qingqi;XU Siqi;HUANG Ruixiao;KONG Xiangrui;YANG Yufei(State Key Laboratory of Environmental Criteria and Risk Assessment,Chinese Research Academy of Environment Sciences,Beijing 100012,China;National Joint Research Center for Ecological Conservation and High Quality Development of the Yellow River Basin,Beijing 100012,China;Beijing No.66 High School,Beijing 100053,China;College of Water Sciences,Beijing Normal University,Beijing 100085,China)
出处
《化工进展》
北大核心
2025年第9期5479-5490,共12页
Chemical Industry and Engineering Progress
基金
黄河流域生态保护和高质量发展联合研究项目(2022-YRUC-01-0301)。
关键词
堆存粉煤灰
淋溶
重金属
环境风险
stockpiled coal fly ash
leaching
heavy metals
environmental risk
作者简介
第一作者:卢永琦(1998-),女,硕士研究生,研究方向为固体废物环境风险控制。E-mail:yongqi 0224@163.com;通信作者:杨玉飞,研究员,硕士生导师,研究方向为固体废物环境风险控制。E-mail:yangyf@craes.org.cn。孔祥蕊,助理研究员,研究方向为固体废物处置与资源化。E-mail:kongxr@craes.org.cn。
