摘要
分别以生石灰和亚铁盐作为辅助剂与稳定剂对2种砷污染的土壤进行稳定化处理,通过化学浸出、形态及结构研究,揭示土壤中有效砷的稳定效率和机理.结果表明,外源铁添加量与土壤砷含量(Fe/As)的物质的量比达到6:1-8:1,CaO投加比例为O.05%-0.1%(w/w)时,土壤中有效态砷的稳定效率超过85%.土壤有效砷的稳定化处理主要是将砷从非专性吸附态和专性吸附态转化为弱结晶的铁铝或铁锰水化氧化物结合态、结晶铁铝或铁锰水化氧化物结合态.稳定处理后2种污染土均有新物相羟砷铜矿(As2CusH4012)生成.
Lime and Ferrous salt was used as the auxiliary agent and stabilizing agent to treat two arsenic contaminated soils. Following chemical leaching test, the stabilizing effectiveness and mechanism of available arsenic on treated soil were shown using morphology and structure analysis. Importantly, the stabilizing efficiency of arsenic for the two types of soils were both over 85% when the ratio of exogenous Fe and soil As (mol/mol) was 6:1-8:1 and the dosing ratio of CaO was 0.05% - 0.1% (w/w). The stabilization of arsenic in soil was attributed mainly to two following reasons: (1) arsenic was transformed from non-specific adsorption and the specific adsorption state into the weakly crystalline Fe-AI or Fe-Mn hydrated oxides and (2) crystalline Fe-A1 or Fe-Mn hydrated oxides state. The new phase of hydroxyl arsenic copper mineral (As2CusH4012) was generated after the stabilization treatment of the contaminated soils.
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2013年第2期298-304,共7页
China Environmental Science
基金
2011年环保公益项目(201109019)
上海市环保科研青年基金项目(沪环科(2011-3))
徐汇区科委项目(RCT201003)
2011年上海市科委迪斯尼专项(11dz1201700)
关键词
土壤
砷
稳定化
形态变化
X射线衍射
soil: arsenic
stabilization treatment
morphological change
X-ray diffraction