摘要
淋滤实验是目前研究固体废弃物中重金属迁移性最常用的方法,为了揭示脱硫石膏中Cr、As、Ni、Pb重金属组分的迁移特征,对脱硫石膏进行赋存形态和淋滤实验的实验研究。结果表明重金属组分大多以氧化物结合态为主,其中FA1中重金属可淋滤态大小为Pb>As>Cr>Ni,而FA2中重金属可淋滤态为As>Pb>Ni>Cr。淋滤实验采用pH为4.0和4.5的醋酸-醋酸钠缓冲溶液为淋滤液,淋滤时间为17 d,淋滤实验结果表明,各重金属的淋出率随淋滤时间的延长而增加;Cr、Ni、Pb组分随着淋滤液pH值降低而增加;重金属的赋存形态对重金属迁移特性有重要影响。脱硫石膏FA1中Cr、As、Ni、Pb以及脱硫石膏FA2中的Cr、Pb的最高淋出量超过《地表水环境质量标准》,在脱硫石膏资源化应用过程中可能对环境造成危害。
Leaching experiment is a commonly method in study of the mobility of heavy metals in solid waste . In order to reveal the characteristics of migration of heavy metals such as Cr, As, Ni and Pb in FGD gypsum components, leaching experiments and occurrence mode experiment were conducted on FGD gypsum. The results showed that oxide was the main components in all heavy metal components. Moreover, there was a descending sequence of Pb, As, Cr, and Ni in the sample FA1, and As, Pb, Ni, and Cr in the sample FA2 according to mobility characteristics. The buffer solution of acetic acid and sodium acetate with pH value of 4.0 and 4.5 was selected as leaching solution, and leaching period was seventeen days. The leaching experimental results indicated that leaching rate of every heavy metal component increased with leaching time increasing. Leaching rate of Cr, Ni and Pb component could be increased with pH value of leaching solution decreasing. The occurrence mode of every heavy metal component influenced leaching rate deeply. In leaching solution, Cr, As, Ni, and Pb ions from sample FA1 and Cr, Pb ions from FA2 were out of the standard of surface water environmental quality. So the potential disadvantage of heavy metal components to environment must be considered in the practice utilization of FGD gypsum.
出处
《环境科学与技术》
CAS
CSCD
北大核心
2017年第3期68-73,共6页
Environmental Science & Technology
基金
湖北省教育厅科学技术研究计划重点项目(D20141105)
关键词
脱硫石膏
重金属组分
赋存形态
批淋滤
迁移特性
FGD gypsum
heavy metal component
occurrence mode
batch leaching
migration characteristics
