PVC浓度对热处理过程中Pb迁移转化的影响
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摘要
生活垃圾热处理过程中含氯化合物的存在会使重金属转化为颗粒更小、更易挥发的重金属氯化物,扩大其环境影响.本文采用热分析和管式炉模拟法,研究在不同气氛下城市生活垃圾中典型有机氯化物——聚氯乙烯(PVC)对重金属Pb迁移转化的影响.结果表明,PVC和PbO共存的体系中,PVC在250℃左右热分解产生HCl,并与PbO反应生成PbCl_2(501℃左右开始挥发)而促进Pb迁移进入烟气.当Cl:Pb物质的量比为2,3,5和10时,在空气气氛下PVC浓度的增加对Pb的挥发没有显著影响,而在氮气气氛下,Cl:Pb=3时,Pb挥发率最大,达到88.19%,Cl:Pb=2时,Pb挥发率最小,为68.60%.
The migration and release of heavy metals during thermal treatment of municipal solid waste(MSW) is an environmental issue of great concern. Chlorine-containing compounds present in MSW could convert heavy metals into smaller particles and volatile chlorides during thermal treatment, thus cause serious environmental pollution. In this study, thermogravimetric analysis and tube furnace were used to investigate the effect of polyvinyl chloride(PVC) on the transformation and migration of Pb under different atmosphere. The results showed that PVC decomposed at 250°C, and then the released HCl reacted with PbO to form PbCl_2(melting point: 501°C), which promoted the migration of Pb into the flue gas. The concentration of PVC(at the molar ratios of Cl:Pb= 2, 3, 5, and 10) had no significant effect on the volatilization of Pb under air atmosphere. While under N_2 atmosphere, the highest volatility of Pb could reach 88.19% at the molar ratio of Cl:Pb=3; the lowest volatility of Pb was 68.60% at the molar ratio of Cl:Pb=2.
The migration and release of heavy metals during thermal treatment of municipal solid waste(MSW) is an environmental issue of great concern. Chlorine-containing compounds present in MSW could convert heavy metals into smaller particles and volatile chlorides during thermal treatment, thus cause serious environmental pollution. In this study, thermogravimetric analysis and tube furnace were used to investigate the effect of polyvinyl chloride(PVC) on the transformation and migration of Pb under different atmosphere. The results showed that PVC decomposed at 250°C, and then the released HCl reacted with PbO to form PbCl_2(melting point: 501°C), which promoted the migration of Pb into the flue gas. The concentration of PVC(at the molar ratios of Cl:Pb= 2, 3, 5, and 10) had no significant effect on the volatilization of Pb under air atmosphere. While under N_2 atmosphere, the highest volatility of Pb could reach 88.19% at the molar ratio of Cl:Pb=3; the lowest volatility of Pb was 68.60% at the molar ratio of Cl:Pb=2.
引文
[1]中国国家统计局.中国统计年鉴[M].北京:中国统计出版社,2018.National Bureau of Statistics of the People's Republic of China.China Statistical Yearbook[M].Beijing:China Statistics Press,2018.
[2]Barton R G,Clark W D,Seeker W R.Fate of metals in waste combustion systems[J].Combustion Science and Technology,1990,74(1-6):327-342.
[3]Zhang H,He P J,Shao L M.Fate of heavy metals during municipal solid waste incineration in Shanghai[J].Journal of Hazardous Materials,2008,156:365-373.
[4]Fernhdez M A,Marfiner L,Segarra M,et al.Behavior of heavy metals in the combustion gases of urban waste incinerators[J].Environmental Science&Technology,1992,5(26):1040-1047.
[5]Davis S,Gale T,Wendt J L.Competition for sodium and toxic metals capture on sorbents[J].Aerosol Science and Technology,2000,32(2):142-151.
[6]李烨玲.靶场土壤中铅的环境行为及生物有效性研究[D].合肥:中国科学技术大学,2018.Li Y L.The environmental fate and bioavailability of lead in shooting range soils[D].Hefei:University of Science and Technology of China,2018.
[7]李建新.垃圾焚烧过程重金属污染物迁移机理及稳定化处理技术研究[D].杭州:浙江大学,2004.Li J X.Transfer mechanism of heavy metals during MSW incineration and solidification/stabilization technology of heavy metals in MSW fly ash.Hangzhou:Zhejiang University,2004.
[8]王玮,魏小林,盛宏至.城市生活垃圾中微量金属元素含量的特性分析[J].环境工程,2004(5):48-50.Wang W,Wei X L,Sheng H Z.Characteristic analysis of trace metals contents in municipal solid waste[J].Environmental Engineering,2004,(5):48-50.
[9]张厚坚,刘海娟,黄世清,等.城市生活垃圾焚烧处理过程中重金属迁移规律研究[J].环境工程学报,2013,7(11):4569-4574.Zhang H J,Liu H J,Huang S Q,et al.Study on the migration rule of heavy metal in waste in incineration[J].Chinese Journal of Environmental Engineering,2013,7(11):4569-4574.
[10]Zhang Y G,Chen Y,Meng A H,et al.Experimental and thermodynamic investigation on transfer of cadmium influenced by sulfur and chlorine during municipal solid waste(MSW)incineration[J].Journal of Hazardous Materials,2008,153(1/2):309-319.
[11]Li W H,Ma Z Y,Huang Q X,et al.Distribution and leaching characteristics of heavy metals in a hazardous waste incinerator[J].Fuel,2018,233:427-441.
[12]Wang L,Wang L A,Zhong S,et al.Pollution and risk assessment of heavy metal in soil surrounding a typical municipal solid waste incineration plant in Chongqing,China.[J].Fresenius Environmental Bulletin,2018,27(8):5486-5492.
[13]李友平,刘慧芳,周洪,等.成都市PM2.5中有毒重金属污染特征及健康风险评价[J].中国环境科学,2015,35(7):2225-2232.Li Y P,Liu H F,Zhou H,et al.Contamination characteristics and health risk assessment of toxic heavy metals in PM2.5 in Chengdu[J].China Environmental Science,2015,35(7):2225-2232.
[14]Kageyama H,Osada S,Nakata H,et al.Effect of coexisting inorganic chlorides on lead volatilization from Ca O-Si O2-Al2O3 molten slag under municipal solid waste gasification and melting conditions[J].Fuel,2013,103:94-100.
[15]Zhang Y,Chen Y,Meng A,et al.Experimental and thermodynamic investigation on transfer of cadmium influenced by sulfur and chlorine during municipal solid waste(MSW)incineration[J].Journal of Hazardous Materials,2008,153(1/2):309-319.
[16]Fraissler G,J?ller M,Brunner T,et al.Influence of dry and humid gaseous atmosphere on the thermal decomposition of calcium chloride and its impact on the remove of heavy metals by chlorination[J].Chemical Engineering and Processing:Process Intensification,2009,48(1):380-388.
[17]Zhu H M,Jiang X G,Yan J H,et al.TG-FTIR analysis of PVCthermal degradation and HCl removal[J].Journal of Analytical and Applied Pyrolysis,2008,82(1):1-9.
[18]陈勇,张衍国,李清海,等.垃圾焚烧中硫化合物对Cd、Pb迁移和转化的影响[J].清华大学学报(自然科学版),2008,(2):232-235.Chen Y,Zhang Y G,Li Q H,et al.Effects of sulfur compounds on Cd and Pb partitioning and speciation in a simulated MSW incinerator[J].Journal of Tsinghua University(Science and Technology),2008,(2):232-235.
[19]Li R,Zhao W,Li Y,et al.Heavy metal removal and speciation transformation through the calcination treatment of phosphorusenriched sewage sludge ash[J].Journal of Hazardous Materials,2015,283:423-431.
[20]Marani D,Braguglia C M,Mininni G,et al.Behaviour of Cd,Cr,Mn,Ni,Pb,and Zn in sewage sludge incineration by fluidised bed furnace[J].Waste Management,2003,23(2):117-124.
[21]Falcoz Q,Gauthier D,Abanades S,et al.Kinetic Rate laws of Cd,Pb,and Zn vaporization during municipal solid waste incineration[J].Environmental Science&Technology,2009,43(6):2184-2189.
[22]Yu S,Zhang B,Wei J,et al.Effects of chlorine on the volatilization of heavy metals during the co-combustion of sewage sludge[J].Waste Management,2017,62:204-210.
[23]Nowak B,Frías Rocha S,Aschenbrenner P,et al.Heavy metal removal from MSW fly ash by means of chlorination and thermal treatment:Influence of the chloride type[J].Chemical Engineering Journal,2012,179:178-185.
[24]Vogel C,Adam C.Heavy metal removal from sewage sludge ash by thermochemical treatment with gaseous hydrochloric acid[J].Environmental Science&Technology,2011,45(17):7445-7450.
[25]Nowak B,Pessl A,Aschenbrenner P,et al.Heavy metal removal from municipal solid waste fly ash by chlorination and thermal treatment[J].Journal of Hazardous Materials,2010,179(1-3):323-331.
[26]Nowak B,Aschenbrenner P,Winter F.Heavy metal removal from sewage sludge ash and municipal solid waste fly ash-A comparison[J].Fuel Processing Technology,2013,105:195-201.
[27]Chiang K Y,Wang K S,Lin F L,et al.Chloride effects on the speciation and partitioning of heavy metal during the municipal solid waste incineration process[J].Science of the Total Environment,1997,203(2):129-140.
[28]Li Q H,Meng A H,Jia J Y,et al.Investigation of heavy metal partitioning influenced by flue gas moisture and chlorine content during waste incineration[J].Journal of Environmental Sciences,2010,5(22):760-768.
[29]Yu J,Sun L,Xiang J,et al.Vaporization of heavy metals during thermal treatment of model solid waste in a fluidized bed incinerator.[J].Chemosphere,2012,86(11):1122-1126.
[30]Vogel C,Exner R M,Adam C.Heavy metal removal from sewage sludge ash by thermochemical treatment with polyvinylchloride[J].Environmental Science&Technology,2012,47(1):563-567.
[31]Wang S,Zhang H,Shao L,et al.Thermochemical reaction mechanism of lead oxide with poly(vinyl chloride)in waste thermal treatment[J].Chemosphere,2014,117:353-359.
[32]Wang S J,He P J,Xia Y,et al.Role of sodium chloride and mineral matrixes in the chlorination and volatilization of lead during waste thermal treatment[J].Fuel Processing Technology,2016,143:130-139.
[33]Peng T H,Lin C L.Influence of various chlorine additives on the partitioning of heavy metals during low-temperature two-stage fluidized bed incineration[J].Journal of Environmental Management,2014,146:362-368.
[34]Watanabe N,Yamamoto O,Sakai M,et al.Combustible and incombustible speciation of Cl and S in various components of municipal solid waste[J].Waste Management,2004,24(6):623-632.
[35]U S Environmental Protection Agency.Method 29-Determination of metal emissions from stationary sources,office of air quality planning and standards[S].1996.
[36]Marongiu A,Faravelli T,Bozzano G,et al.Thermal degradation of poly(vinyl chloride)[J].Journal of Analytical and Applied Pyrolysis,2003,70(2):519-553.
[37]Ma S B,Lu J,Gao J S.Study of the low temperature pyrolysis of PVC[J].Energy&Fuels,2002,16(2):338-342.
[38]任浩华,王帅,王芳杰,等.PVC热解过程中HCl的生成及其影响因素[J].中国环境科学,2015,35(8):2460-2469.Ren H H,Wang S,Wang F J,et al.HCl generation reaction and its influence factors during PVC pyrolysis[J].China Environmental Science,2015,35(8):2460-2469.
[2]Barton R G,Clark W D,Seeker W R.Fate of metals in waste combustion systems[J].Combustion Science and Technology,1990,74(1-6):327-342.
[3]Zhang H,He P J,Shao L M.Fate of heavy metals during municipal solid waste incineration in Shanghai[J].Journal of Hazardous Materials,2008,156:365-373.
[4]Fernhdez M A,Marfiner L,Segarra M,et al.Behavior of heavy metals in the combustion gases of urban waste incinerators[J].Environmental Science&Technology,1992,5(26):1040-1047.
[5]Davis S,Gale T,Wendt J L.Competition for sodium and toxic metals capture on sorbents[J].Aerosol Science and Technology,2000,32(2):142-151.
[6]李烨玲.靶场土壤中铅的环境行为及生物有效性研究[D].合肥:中国科学技术大学,2018.Li Y L.The environmental fate and bioavailability of lead in shooting range soils[D].Hefei:University of Science and Technology of China,2018.
[7]李建新.垃圾焚烧过程重金属污染物迁移机理及稳定化处理技术研究[D].杭州:浙江大学,2004.Li J X.Transfer mechanism of heavy metals during MSW incineration and solidification/stabilization technology of heavy metals in MSW fly ash.Hangzhou:Zhejiang University,2004.
[8]王玮,魏小林,盛宏至.城市生活垃圾中微量金属元素含量的特性分析[J].环境工程,2004(5):48-50.Wang W,Wei X L,Sheng H Z.Characteristic analysis of trace metals contents in municipal solid waste[J].Environmental Engineering,2004,(5):48-50.
[9]张厚坚,刘海娟,黄世清,等.城市生活垃圾焚烧处理过程中重金属迁移规律研究[J].环境工程学报,2013,7(11):4569-4574.Zhang H J,Liu H J,Huang S Q,et al.Study on the migration rule of heavy metal in waste in incineration[J].Chinese Journal of Environmental Engineering,2013,7(11):4569-4574.
[10]Zhang Y G,Chen Y,Meng A H,et al.Experimental and thermodynamic investigation on transfer of cadmium influenced by sulfur and chlorine during municipal solid waste(MSW)incineration[J].Journal of Hazardous Materials,2008,153(1/2):309-319.
[11]Li W H,Ma Z Y,Huang Q X,et al.Distribution and leaching characteristics of heavy metals in a hazardous waste incinerator[J].Fuel,2018,233:427-441.
[12]Wang L,Wang L A,Zhong S,et al.Pollution and risk assessment of heavy metal in soil surrounding a typical municipal solid waste incineration plant in Chongqing,China.[J].Fresenius Environmental Bulletin,2018,27(8):5486-5492.
[13]李友平,刘慧芳,周洪,等.成都市PM2.5中有毒重金属污染特征及健康风险评价[J].中国环境科学,2015,35(7):2225-2232.Li Y P,Liu H F,Zhou H,et al.Contamination characteristics and health risk assessment of toxic heavy metals in PM2.5 in Chengdu[J].China Environmental Science,2015,35(7):2225-2232.
[14]Kageyama H,Osada S,Nakata H,et al.Effect of coexisting inorganic chlorides on lead volatilization from Ca O-Si O2-Al2O3 molten slag under municipal solid waste gasification and melting conditions[J].Fuel,2013,103:94-100.
[15]Zhang Y,Chen Y,Meng A,et al.Experimental and thermodynamic investigation on transfer of cadmium influenced by sulfur and chlorine during municipal solid waste(MSW)incineration[J].Journal of Hazardous Materials,2008,153(1/2):309-319.
[16]Fraissler G,J?ller M,Brunner T,et al.Influence of dry and humid gaseous atmosphere on the thermal decomposition of calcium chloride and its impact on the remove of heavy metals by chlorination[J].Chemical Engineering and Processing:Process Intensification,2009,48(1):380-388.
[17]Zhu H M,Jiang X G,Yan J H,et al.TG-FTIR analysis of PVCthermal degradation and HCl removal[J].Journal of Analytical and Applied Pyrolysis,2008,82(1):1-9.
[18]陈勇,张衍国,李清海,等.垃圾焚烧中硫化合物对Cd、Pb迁移和转化的影响[J].清华大学学报(自然科学版),2008,(2):232-235.Chen Y,Zhang Y G,Li Q H,et al.Effects of sulfur compounds on Cd and Pb partitioning and speciation in a simulated MSW incinerator[J].Journal of Tsinghua University(Science and Technology),2008,(2):232-235.
[19]Li R,Zhao W,Li Y,et al.Heavy metal removal and speciation transformation through the calcination treatment of phosphorusenriched sewage sludge ash[J].Journal of Hazardous Materials,2015,283:423-431.
[20]Marani D,Braguglia C M,Mininni G,et al.Behaviour of Cd,Cr,Mn,Ni,Pb,and Zn in sewage sludge incineration by fluidised bed furnace[J].Waste Management,2003,23(2):117-124.
[21]Falcoz Q,Gauthier D,Abanades S,et al.Kinetic Rate laws of Cd,Pb,and Zn vaporization during municipal solid waste incineration[J].Environmental Science&Technology,2009,43(6):2184-2189.
[22]Yu S,Zhang B,Wei J,et al.Effects of chlorine on the volatilization of heavy metals during the co-combustion of sewage sludge[J].Waste Management,2017,62:204-210.
[23]Nowak B,Frías Rocha S,Aschenbrenner P,et al.Heavy metal removal from MSW fly ash by means of chlorination and thermal treatment:Influence of the chloride type[J].Chemical Engineering Journal,2012,179:178-185.
[24]Vogel C,Adam C.Heavy metal removal from sewage sludge ash by thermochemical treatment with gaseous hydrochloric acid[J].Environmental Science&Technology,2011,45(17):7445-7450.
[25]Nowak B,Pessl A,Aschenbrenner P,et al.Heavy metal removal from municipal solid waste fly ash by chlorination and thermal treatment[J].Journal of Hazardous Materials,2010,179(1-3):323-331.
[26]Nowak B,Aschenbrenner P,Winter F.Heavy metal removal from sewage sludge ash and municipal solid waste fly ash-A comparison[J].Fuel Processing Technology,2013,105:195-201.
[27]Chiang K Y,Wang K S,Lin F L,et al.Chloride effects on the speciation and partitioning of heavy metal during the municipal solid waste incineration process[J].Science of the Total Environment,1997,203(2):129-140.
[28]Li Q H,Meng A H,Jia J Y,et al.Investigation of heavy metal partitioning influenced by flue gas moisture and chlorine content during waste incineration[J].Journal of Environmental Sciences,2010,5(22):760-768.
[29]Yu J,Sun L,Xiang J,et al.Vaporization of heavy metals during thermal treatment of model solid waste in a fluidized bed incinerator.[J].Chemosphere,2012,86(11):1122-1126.
[30]Vogel C,Exner R M,Adam C.Heavy metal removal from sewage sludge ash by thermochemical treatment with polyvinylchloride[J].Environmental Science&Technology,2012,47(1):563-567.
[31]Wang S,Zhang H,Shao L,et al.Thermochemical reaction mechanism of lead oxide with poly(vinyl chloride)in waste thermal treatment[J].Chemosphere,2014,117:353-359.
[32]Wang S J,He P J,Xia Y,et al.Role of sodium chloride and mineral matrixes in the chlorination and volatilization of lead during waste thermal treatment[J].Fuel Processing Technology,2016,143:130-139.
[33]Peng T H,Lin C L.Influence of various chlorine additives on the partitioning of heavy metals during low-temperature two-stage fluidized bed incineration[J].Journal of Environmental Management,2014,146:362-368.
[34]Watanabe N,Yamamoto O,Sakai M,et al.Combustible and incombustible speciation of Cl and S in various components of municipal solid waste[J].Waste Management,2004,24(6):623-632.
[35]U S Environmental Protection Agency.Method 29-Determination of metal emissions from stationary sources,office of air quality planning and standards[S].1996.
[36]Marongiu A,Faravelli T,Bozzano G,et al.Thermal degradation of poly(vinyl chloride)[J].Journal of Analytical and Applied Pyrolysis,2003,70(2):519-553.
[37]Ma S B,Lu J,Gao J S.Study of the low temperature pyrolysis of PVC[J].Energy&Fuels,2002,16(2):338-342.
[38]任浩华,王帅,王芳杰,等.PVC热解过程中HCl的生成及其影响因素[J].中国环境科学,2015,35(8):2460-2469.Ren H H,Wang S,Wang F J,et al.HCl generation reaction and its influence factors during PVC pyrolysis[J].China Environmental Science,2015,35(8):2460-2469.