AOD渣中铬的连续淋溶特性及其动力学模型的构建
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摘要
为评价AOD(氩氧脱碳炉)渣的淋溶毒性,采用连续20 d的静态淋溶试验,研究了中性和酸性淋溶液对AOD炉渣中Cr(铬)淋溶特性的影响,以累积溶出率构建了Cr淋溶动力学模型.结果表明:在连续淋溶过程中,淋溶液p H(9.6~11.5)始终保持碱性,DO(溶解氧)基本处于饱和状态,淋溶液还原性呈降低趋势;随着淋溶时间的延长,淋溶液中Cr6+、TCr和Cr3+的累积溶出率呈增加趋势,不同初始淋溶液p H(2.0、3.0、4.0、5.0、6.0、7.0)下,连续淋溶20 d时Cr6+、TCr和Cr3+的累积溶出率分别是淋溶2 d时的10.1~22.2、7.5~15.6、6.3~17.1倍;与中性和弱酸性淋溶液相比,连续淋溶20 d,酸性较强的淋溶液中Cr6+、TCr和Cr3+的累积溶出率分别为其3.1~6.6、1.6~3.2和1.8~2.1倍;与短期静态淋溶相比,连续淋溶增加了淋溶液总量,尽管ρ(Cr)变化较小,但TCr累积溶出率显著增加;双常数速率、抛物线和指数模型均可拟合淋溶液中Cr6+、TCr和Cr3+的累积溶出率,其中,抛物线模型的相关系数均在0.99以上,是最佳模型.AOD渣中Cr的连续淋溶动力学模型的构建可为不锈钢渣中Cr的淋溶毒性及其生态风险评价奠定试验和理论基础.
Twenty days sequential leaching experiments were carried out to investigate the leaching characteristics of chromium from AOD slag by neutral and acidic leachate. A kinetic model of chromium leaching was established based on the accumulated leaching ratio,which provides an experimental foundation for leaching toxicity assessment of AOD slag. It was shown that during the sequential leaching period,the leachates maintained strong basicity,with their p Hs being 9. 6-11. 5,while the dissolved oxygen was saturated and the reducibility of leachate trend declined. The accumulated leaching ratio of Cr6 +,total chromium and Cr3 +increased rapidly with increasing leaching time. When the initial p Hs of leachate were 2. 0,3. 0,4. 0,5. 0,6. 0 and 7. 0,the accumulated leaching ratios of Cr6 +,total chromium and Cr3 +in the leachates of 20 d sequential leaching were 10. 1-22. 2,7. 5-15. 6 and 6. 3-17. 1 times,respectively,than those in the leachates of 2 d sequential leaching. Compared with the neutral and weakly acidic leachate,the accumulated leaching ratio of Cr6 +,total chromium and Cr3 +in strong acidic leachate were 3. 1-6. 6,1. 6-3. 2 and 1. 8-2. 1 times,respectively,when the sequential leaching time was 20 d. Different from the short-term static state leaching process,the leachate volume increased in the sequential leaching process.The total leaching chromium ratio significantly increased though the chromium concentration in the leachates of sequential leaching process was stable. The accumulated leaching ratios of Cr6 +,total chromium and Cr3 +in leachate could be fitted with double constant,parabolic and exponential models. Compared with the other two models,the parabolic model was more suitable to describe the accumulated leaching ratio of Cr6 +,total chromium and Cr3 +from AOD slag,which was the optimizing model for predicting the leaching quantity of chromium in sequential leaching tests,and provided an experimental and theoretical foundation for the leaching toxicity and eco-risk assessment.
Twenty days sequential leaching experiments were carried out to investigate the leaching characteristics of chromium from AOD slag by neutral and acidic leachate. A kinetic model of chromium leaching was established based on the accumulated leaching ratio,which provides an experimental foundation for leaching toxicity assessment of AOD slag. It was shown that during the sequential leaching period,the leachates maintained strong basicity,with their p Hs being 9. 6-11. 5,while the dissolved oxygen was saturated and the reducibility of leachate trend declined. The accumulated leaching ratio of Cr6 +,total chromium and Cr3 +increased rapidly with increasing leaching time. When the initial p Hs of leachate were 2. 0,3. 0,4. 0,5. 0,6. 0 and 7. 0,the accumulated leaching ratios of Cr6 +,total chromium and Cr3 +in the leachates of 20 d sequential leaching were 10. 1-22. 2,7. 5-15. 6 and 6. 3-17. 1 times,respectively,than those in the leachates of 2 d sequential leaching. Compared with the neutral and weakly acidic leachate,the accumulated leaching ratio of Cr6 +,total chromium and Cr3 +in strong acidic leachate were 3. 1-6. 6,1. 6-3. 2 and 1. 8-2. 1 times,respectively,when the sequential leaching time was 20 d. Different from the short-term static state leaching process,the leachate volume increased in the sequential leaching process.The total leaching chromium ratio significantly increased though the chromium concentration in the leachates of sequential leaching process was stable. The accumulated leaching ratios of Cr6 +,total chromium and Cr3 +in leachate could be fitted with double constant,parabolic and exponential models. Compared with the other two models,the parabolic model was more suitable to describe the accumulated leaching ratio of Cr6 +,total chromium and Cr3 +from AOD slag,which was the optimizing model for predicting the leaching quantity of chromium in sequential leaching tests,and provided an experimental and theoretical foundation for the leaching toxicity and eco-risk assessment.
引文
[1]郑娜,李俊国,王亚军.AOD渣中铬的短期淋溶特性[J].环境科学与技术,2013,36(6):82-85.ZHENG Na,LI Junguo,WANG Yajun.Short-term leaching characteristics of chromium in the AOD slag[J].Environmental Science&Technology(China),2013,36(6):82-85.
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[3]WINDT L D,CHAURAND P,ROSE J.Kinetics of steel slag leaching:batch tests and modeling[J].Waste Management,2011,31:225-235.
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[5]刘玉强,李丽,王琪,等.典型铬渣污染场地的污染状况与综合治理对策[J].环境科学研究,2009,22(2):248-253.LIU Yuqiang,LI Li,WANG Qi,et al.Study on pollution situation at typical chrome residue contaminated sites and corresponding integrated remediation plan[J].Research of Environmental Sciences,2009,22(2):248-253.
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[8]WANG Ruyi,CHEN Ronghuan,SHI Lei.Beneficial use of stainless steel EAF slag as composite cement admixture and its heavy metals leaching risk analysis[J].Baosteel Technical Research,2009,3(4):14-18.
[9]国家环境保护总局.水和废水的监测分析方法[M].4版.北京:中国环境科学出版社,2002:346-349.
[10]YU Suyuan.Aerosol behavior in chromium waste incineration[J].China Particuology Science and Technology of Particles,2003(1):47-51.
[11]WANG Qinag,YAH Peiyu,FENG Jianwen.A discussion on improving hydration activity of steel slag by altering its mineral compositions[J].Journal of Hazardous Materials,2011,186:1070-1075.
[12]CHEN Quanyuan,JOHNSON D C,ZHU Lingyun,et al.Accelerated carbonation and leaching behavior of the slag from iron and steel making industry[J].Journal of University of Science and Technology Beijing,2007,14(4):297-301.
[13]KUO Yiming,WANG Jianwen,WANG Chihta,et al.Effect of water quenching and Si O2addition during vitrification of fly ash:Part1.on the crystalline characteristics of slags[J].Jounal of Hazardous Materials,2008,152:994-1001.
[14]SAMADA Y,MIKI T,HINO M.Prevention of chromium elution from stainless stell slag into seawater[J].ISIJ International,2011,51(5):728-732.
[15]MAWEJA K,MUKONGO T,RICHARD K M,et al.Effect of annealing treatment on the crystallisatior and leading of dumped base metal smelter slags[J].Journal of Hazardous Materials,2010,183:294-300.
[16]PILLAY K,BLOTTNITZ H V,PETERSEB J.Ageing of chromium(Ⅲ)-bearing slag and its relation to the atmospheric oxidation of solid chromium(Ⅲ)-oxide in the presence of calcium oxide[J].Chemosphere,2003,52:1771-1779.
[17]颜湘华,王兴润,李丽,等.铬污染场地调查数据评估与暴露浓度估计[J].环境科学研究,2013,26(1):103-108.YAN Xianghua,WANG Xingrun,LI Li,et al.Estimating exposure point concentrations and evaluating survey data for a chromiumcontaminated site[J].Research of Environmental Sciences,2013,26(1):103-108.
[18]WANG Qiang,YAN Peiyu.Hyddration properties of basic oxygen furnace steel slag[J].Construction and Building Materials,2010,24:1134-1140.
[19]XIAO Qinggui,CHEN Yin,PEI Lili,et al.Leading of silica from vanadium-bearing steel slag in sodium dydroxide solution[J].Jounal of Chinese Rare Earth Society,2011,28:435-439.
[20]孙志良,朱耀华,张大年.铬渣中Cr6+的溶出特性研究[J].上海环境科学,1992,11(3):13-16.SUN Zhiliang,ZHU Yaohua,ZHANG Danian.Study on the leaching characteristics of Cr(Ⅵ)in chromic slag[J].Shanghai Environmental Sciences,1992,11(3):13-16.
[21]国家环境保护总局.GBT 15555.4—1995固体废物六价铬的测定二苯碳酰二肼分光光度法[S].北京:中国环境科学出版社,1995:539-542.
[22]陈跃文,田衫.分光光度法测定总铬的改进[J].黑龙江环境通报,2008,32(2):61-66.CHEN Yuewen,TIAN Shan.Improvement of determining total chrome with spectrophotometric method[J].Heilongjiang Environmental Journal,2008,32(2):61-66.
[23]张慧.分光光度法测定铬的改进[J].宁波大学学报,2002,15(2):42-44.ZHANG Hui.Improvement on the spectrophotometric method to determine chromium[J].Journal of Ningbo University,2002,15(2):42-44.
[24]RONALD L D.Theory and practice of water and waste water treatment[M].New York:Wiley,1997:44.
[25]杨南如.一类新的胶凝材料[J].水泥技术,2004(3):11-17.
[26]王亚军,李俊国,郑娜.AOD不锈钢渣矿相组成及其显微形貌[J].钢铁钒钛,2013,34(4):68-72.WANG Yajun,LI Junguo,ZHENG Na.Mineral compositions and microstructures of AOD stainless steel slag[J].Iron Steel Vanadium Titanium,2013,34(4):68-72.
[27]戴树桂.环境化学[M].北京:高等教育出版社,2006:150.
[28]闵世俊.钒钛磁铁矿尾矿中钒的提取工艺和动力学研究[D].成都:成都理工大学,2009.
[29]PONCE S C,PRADO C,PAGANNO E,et al.Effect of solution p H on the dynamic of biosorption of Cr(Ⅵ)by living plants of salvinia minima[J].Ecology Engineering,2014,74:33-41.
[30]张翔宇,何晶晶,章弊,等.不锈钢渣资源利用特性与重金属污染风险[J].环境科学研究,2008,21(4):33-37.ZHANG Xiangyu,HE Jingjing,ZHANG Bi,et al.Beneficial reuse of stainless steel slag and its heavy metals pollution risk[J].Research of Environmental Sciences,2008,21(4):33-37.
[31]胡恭任,于瑞莲,刘海婷,等.模拟酸雨对街道灰尘重金属淋溶的累积释放特征与释放模型[J].环境化学,2013,32(5):886-892.HU Gongren,YU Ruilian,LIU Haiting,et al.Releasing characteristics and models of heavy metals from street dust leached by simulated acid rain[J].Environmental Chemistry,2013,32(5):886-892.
[32]甄常亮,那贤昭,齐渊洪,等.不锈钢渣毒性浸出特征及无害化处置现状[J].钢铁研究学报,2012,24(10):1-5.ZHEN Changliang,NA Xianzhao,QI Yuanhong,et al,Toxicity leaching characteristic and harmless disposal of stainless steel slag[J].Journal of Iron and Steel Research,2012,24(10):1-5.
[2]关伯仁.环境科学基础教程[M].北京:中国环境科学出版社,1997.
[3]WINDT L D,CHAURAND P,ROSE J.Kinetics of steel slag leaching:batch tests and modeling[J].Waste Management,2011,31:225-235.
[4]王琪,黄启飞,段华波,等.我国危险废物特性鉴别技术体系研究[J].环境科学研究,2006,19(5):165-179.WANG Qi,HUANG Qifei,DUAN Huabo,et al.Study on technical system of China for identification of hazardous wastes[J].Research of Environmental Sciences,2006,19(5):165-179.
[5]刘玉强,李丽,王琪,等.典型铬渣污染场地的污染状况与综合治理对策[J].环境科学研究,2009,22(2):248-253.LIU Yuqiang,LI Li,WANG Qi,et al.Study on pollution situation at typical chrome residue contaminated sites and corresponding integrated remediation plan[J].Research of Environmental Sciences,2009,22(2):248-253.
[6]DAS B,PRAKASH S,REDDY P S R,et al.An overview of utilization of slag and sludge from steel industries[J].Resources,Conservation and Recycling,2007,50:40-57.
[7]APPELO C A J,POSTMA D.Geochemistry,groundwater and pollution(revised edition)[M].Leiden,Netherlands:Taylor&Francis Publishers,1996.
[8]WANG Ruyi,CHEN Ronghuan,SHI Lei.Beneficial use of stainless steel EAF slag as composite cement admixture and its heavy metals leaching risk analysis[J].Baosteel Technical Research,2009,3(4):14-18.
[9]国家环境保护总局.水和废水的监测分析方法[M].4版.北京:中国环境科学出版社,2002:346-349.
[10]YU Suyuan.Aerosol behavior in chromium waste incineration[J].China Particuology Science and Technology of Particles,2003(1):47-51.
[11]WANG Qinag,YAH Peiyu,FENG Jianwen.A discussion on improving hydration activity of steel slag by altering its mineral compositions[J].Journal of Hazardous Materials,2011,186:1070-1075.
[12]CHEN Quanyuan,JOHNSON D C,ZHU Lingyun,et al.Accelerated carbonation and leaching behavior of the slag from iron and steel making industry[J].Journal of University of Science and Technology Beijing,2007,14(4):297-301.
[13]KUO Yiming,WANG Jianwen,WANG Chihta,et al.Effect of water quenching and Si O2addition during vitrification of fly ash:Part1.on the crystalline characteristics of slags[J].Jounal of Hazardous Materials,2008,152:994-1001.
[14]SAMADA Y,MIKI T,HINO M.Prevention of chromium elution from stainless stell slag into seawater[J].ISIJ International,2011,51(5):728-732.
[15]MAWEJA K,MUKONGO T,RICHARD K M,et al.Effect of annealing treatment on the crystallisatior and leading of dumped base metal smelter slags[J].Journal of Hazardous Materials,2010,183:294-300.
[16]PILLAY K,BLOTTNITZ H V,PETERSEB J.Ageing of chromium(Ⅲ)-bearing slag and its relation to the atmospheric oxidation of solid chromium(Ⅲ)-oxide in the presence of calcium oxide[J].Chemosphere,2003,52:1771-1779.
[17]颜湘华,王兴润,李丽,等.铬污染场地调查数据评估与暴露浓度估计[J].环境科学研究,2013,26(1):103-108.YAN Xianghua,WANG Xingrun,LI Li,et al.Estimating exposure point concentrations and evaluating survey data for a chromiumcontaminated site[J].Research of Environmental Sciences,2013,26(1):103-108.
[18]WANG Qiang,YAN Peiyu.Hyddration properties of basic oxygen furnace steel slag[J].Construction and Building Materials,2010,24:1134-1140.
[19]XIAO Qinggui,CHEN Yin,PEI Lili,et al.Leading of silica from vanadium-bearing steel slag in sodium dydroxide solution[J].Jounal of Chinese Rare Earth Society,2011,28:435-439.
[20]孙志良,朱耀华,张大年.铬渣中Cr6+的溶出特性研究[J].上海环境科学,1992,11(3):13-16.SUN Zhiliang,ZHU Yaohua,ZHANG Danian.Study on the leaching characteristics of Cr(Ⅵ)in chromic slag[J].Shanghai Environmental Sciences,1992,11(3):13-16.
[21]国家环境保护总局.GBT 15555.4—1995固体废物六价铬的测定二苯碳酰二肼分光光度法[S].北京:中国环境科学出版社,1995:539-542.
[22]陈跃文,田衫.分光光度法测定总铬的改进[J].黑龙江环境通报,2008,32(2):61-66.CHEN Yuewen,TIAN Shan.Improvement of determining total chrome with spectrophotometric method[J].Heilongjiang Environmental Journal,2008,32(2):61-66.
[23]张慧.分光光度法测定铬的改进[J].宁波大学学报,2002,15(2):42-44.ZHANG Hui.Improvement on the spectrophotometric method to determine chromium[J].Journal of Ningbo University,2002,15(2):42-44.
[24]RONALD L D.Theory and practice of water and waste water treatment[M].New York:Wiley,1997:44.
[25]杨南如.一类新的胶凝材料[J].水泥技术,2004(3):11-17.
[26]王亚军,李俊国,郑娜.AOD不锈钢渣矿相组成及其显微形貌[J].钢铁钒钛,2013,34(4):68-72.WANG Yajun,LI Junguo,ZHENG Na.Mineral compositions and microstructures of AOD stainless steel slag[J].Iron Steel Vanadium Titanium,2013,34(4):68-72.
[27]戴树桂.环境化学[M].北京:高等教育出版社,2006:150.
[28]闵世俊.钒钛磁铁矿尾矿中钒的提取工艺和动力学研究[D].成都:成都理工大学,2009.
[29]PONCE S C,PRADO C,PAGANNO E,et al.Effect of solution p H on the dynamic of biosorption of Cr(Ⅵ)by living plants of salvinia minima[J].Ecology Engineering,2014,74:33-41.
[30]张翔宇,何晶晶,章弊,等.不锈钢渣资源利用特性与重金属污染风险[J].环境科学研究,2008,21(4):33-37.ZHANG Xiangyu,HE Jingjing,ZHANG Bi,et al.Beneficial reuse of stainless steel slag and its heavy metals pollution risk[J].Research of Environmental Sciences,2008,21(4):33-37.
[31]胡恭任,于瑞莲,刘海婷,等.模拟酸雨对街道灰尘重金属淋溶的累积释放特征与释放模型[J].环境化学,2013,32(5):886-892.HU Gongren,YU Ruilian,LIU Haiting,et al.Releasing characteristics and models of heavy metals from street dust leached by simulated acid rain[J].Environmental Chemistry,2013,32(5):886-892.
[32]甄常亮,那贤昭,齐渊洪,等.不锈钢渣毒性浸出特征及无害化处置现状[J].钢铁研究学报,2012,24(10):1-5.ZHEN Changliang,NA Xianzhao,QI Yuanhong,et al,Toxicity leaching characteristic and harmless disposal of stainless steel slag[J].Journal of Iron and Steel Research,2012,24(10):1-5.