用改性钢渣磷肥修复污染土壤的效果  

Lead-contaminatedsoils Stabilized by Modified Thomas Phosphate

作　　者：张坤 韩晶晶 ZHANG Kun;HAN Jingjing(School of Civil Architectural and Environmental Engineering,Xihua University,Chengdu 610039 China)

机构地区：[1]西华大学土木建筑与环境学院,四川成都610039

出　　处：《西华大学学报（自然科学版）》2018年第2期29-33,共5页Journal of Xihua University:Natural Science Edition

摘　　要：随着产业结构的进一步调整与升级,大量工业污染场地亟待修复。钢渣磷肥(thomas phosphate,TP)可用作重金属污染场地修复,但溶解度低的问题制约了其进一步应用。为提高TP的溶解度,本文采用不同酸、不同浓度、不同养护龄期对TP进行改性处理;然后,筛选出2种改性TP,研究铅污染土的修复效果。土壤中重金属铅的初始质量分数为500、2 000和5 000 mg/kg,TP掺量为3%~35%,养护龄期为7 d和28 d。研究结果表明:醋酸改性钢渣磷肥(A-TP)和硝酸改性钢渣磷肥(A-TP)的p H值和钙离子溶出量均较大,电阻率较小,可用作修复铅污染土的备选材料;进一步对其修复效果进行研究,在土壤中铅质量分数不高于2 000 mg/kg时,A-TP(掺量15%)修复土和N-TP(掺量20%)修复土28 d养护后均可满足要求,A-TP使用掺量较小,经济性较好;当土壤中重金属铅含量较高(5 000 mg/kg)时,2种改性钢渣磷肥修复效果均无法满足要求,需考虑同其他修复材料结合使用,以提高修复效果。The Thomas phosphate(TP)is extensively used in heavy metal-contaminated soils stabilization.However,the low solubility of TP has negative effects on stabilizing heavy metal-contaminated clay.In order to improve the solubility of TP,TP was modified by different acid,different concentration and curing age.Then,two kinds of modified TP were screened,and the restoration effect of lead contaminated soil was studied.The TCLPs of Pb-contaminated clay stabilized by selected acid modified TP with curing 7 days and 28 days were studied.The designed concentrations of Pb were 500,2 000,and 5 000 mg/kg(by dry weight),and the TP contents were from 3%to 35%.The results indicate that acetic acid modified TP and nitric acid modified TP have superior characteristics compared to other modified TP.They have the greater pH value and calcium dissolved content([Ca]),and lower electrical resistivity value.Furthermore,when the Pb concentration is no more than 2 000 mg/kg,both acetic acid modified TP and nitric acid modified TP can satisfy the requirement of US EPA.When the Pb concentration is 5 000 mg/kg,the parents TP cannot stabilize the Pb-contaminated clay enough to satisfy the standard,and the additive stabilizer should be considered in order to improving the effects of stabilization.

关 键 词：钢渣磷肥 铅污染土 溶出特性 重金属污染 土壤修复 

分 类 号：TU473.1[建筑科学—结构工程] X53[建筑科学—土工工程]