摘要
铬渣是一种危险废物,其无序堆放对环境造成威胁.本研究中,一种新型的还原剂无定形FeS2被合成出来用于处理铬渣.通过分析两种pH值条件下(pH9代表陈化的铬渣,pH12代表新鲜的铬渣)铬的浸出毒性、生物可给性和铬形态的变化来评价无定形FeS2对铬渣中六价铬的稳定作用.结果表明,pH12比pH9更有利于浸出毒性的降低.pH12条件下,加入2倍化学计量比的无定形FeS2的铬渣在第1天达到国标(GB 5085.3—2007),第30天达到美国国家环保局标准(40 CFR 261.24).然而在pH9条件下,达到相同的表现需要加入4倍化学计量比的无定形FeS2.此外,pH值、氧化还原电位和硫的形态分析结果也表明,无定形FeS2对铬渣中六价铬有较好的还原和稳定能力,且pH12比pH9更有利于还原条件的维持.与之相反的是,pH9比pH12更有利于生物可给性的降低.
Chromite ore processing residue(COPR)is a kind of hazardous wastes which is a big threat to the environment.A novel reductant,amorphous FeS2(FeS2(am))was fabricated for the remediation of COPR in this study.The stabilization effects of FeS2(am)on Cr(VI)in COPR was assessed via analyzing the variation of the leachability,bioaccessibility and speciation of chromium under two pH conditions(pH9 represents the aged COPR and pH12 represents the fresh COPR).Results showed that pH12 was better for the reduction of leachability than pH9.The addition of 2×the stoichiometry of FeS2(am)could meet the Chinese standard(GB 5085.3—2007)at Day 1 and meet the US EPA standard(40 CFR 261.24)at Day 30 under the condition of pH12.However,4×the stoichiometry of FeS2(am)was required to achieve the same performances under the condition of pH9.Moreover,the change of pH,redox potential and the speciation of sulfur also showed that FeS2(am)have a great reduction and stabilization ability on Cr(VI)in COPR,and pH12 was better for the maintenance of reduction condition than pH9.However,pH9 was better for the reduction of bioaccessibility than pH12.
作者
李芸邑
廖珍珠
王航
叶姜瑜
刘阳生
徐凤
王东
LI Yunyi;LIAO Zhenzhu;WANG Hang;YE Jiangyu;LIU Yangsheng;XU Feng;WANG Dong(College of Environmental and Engineering,Key Laboratory of Three Gorges Reservoir Region’s Eco-Environment,Ministry of Education,Chongqing University,Chongqing 400045,China;College of Environmental Sciences and Engineering,Beijing Key Laboratory for Solid Waste Utilization and Management,Peking University,Beijing 100871,China;PowerChina Sichuan Electric Power Engineering Co.,Ltd.,Chengdu 610041,China;Chongqing Solid Waste Management Center,Chongqing 400015,China)
出处
《应用基础与工程科学学报》
EI
CSCD
北大核心
2021年第3期533-544,共12页
Journal of Basic Science and Engineering
基金
重庆市基础科学与前沿技术研究项目(cstc2018jcyjAX0320)
国家自然科学基金面上项目(51778084)
中央高校基本科研业务费项目(2018CDXYCH0013)
关键词
铬渣
六价铬
二硫化亚铁
pH影响
化学还原法
稳定化
浸出毒性
生物可给性
铬形态
COPR
hexavalent chromium
iron bisulfide
pH influence
chemical reduction
stabilization
leachability
bioaccessibility
Cr speciation
