城市生活垃圾热解过程中重金属残留实验研究
摘要
随着城市规模的扩大,我国及世界范围内城市生活垃圾产量与日俱增。垃圾衍生燃料(RDF)代替传统燃料的课题正逐渐受到重视,热解技术在处理城市生活垃圾方面比焚烧有很大的优势。本文结合RDF技术和热解技术处理城市生活垃圾,分析了在热解过程中,不同温度、氧气含量、水蒸气条件对重金属迁移的影响,得出了重金属留在残渣中所需最佳热解条件。研究成果对减少重金属对环境的二次污染和重金属回收有实际应用价值。
实验采用自制的热解设备对RDF进行热解,分别用王水,HNO_3/HClO_4进行消解,并用火焰原子吸收分光光度仪和电感耦合等离子发射光谱仪测定了每次实验中残渣中重金属Cu、Pb、Cd、Cr和重金属Zn的含量,分析了不同温度、氧含量、水蒸气条件对金属迁移的影响。
研究结果表明:
(1)随着温度的升高和氧含量的增加,金属在残渣中的残留量降低。
(2)金属Cu和Pb在通入氧气的情况下,随着温度的升高,氧气的氧化性逐渐增强,并呈现线性关系;金属Cd在900℃左右,在残渣中的残留量相对800℃时差别不大,说明升高温度也不会对减少Cd的残留量产生太大影响。而Zn和Cr的趋势与Cd相反,当强调Zn和Cr在残渣中残留量时,应该特别注意将热解温度保持在较低的温度。
(3)相同温度条件下,金属的沸点越低,残留量越少。
(4) Cr和Cu受温度的影响较大,高温将促进Cr和Cu的挥发,减少其在残渣中残留量,因此应该着重注意将热解温度保持在较低的温度。
With the expansion of the cities, municipal solid waste production is increasing in China and over the world. Using refuse derived fuels instead of traditional fuels are gradually be an important subject, and pyrolysis technology has great advantages than incineration technology in municipal solid waste disposing. RDF technology and pyrolysis technology are combined to dispose the solid waste. A pyrolysis apparatus was designed and manufactured for pyrolysis of RDF. The pyrolysis residues were digested using qua fortis, HNO_3 / HCIO_4 respectively. The heavy metal contents including Cu, Pb, Cd, Cr and Zn in the residues were measured by flame atomic absorption spectrophotometer and inductively coupled plasma-atomic emission spectrometry.
The effects of temperature and oxygen concentration on the amounts of heavy metal contents in the residues were investigated. It was found that:
(l)The heavy metal contents in the residues decreased with increasing pyrolysis temperature and increasing oxygen content.
(2) When oxygen exists, Cu and Pb with increasing temperature, oxygen oxidation gradually increased, and showed a linear relationship; the mass fraction of Cd at 900°C is the same as the mass fraction at 800°C The mining is high temperature has little impact to Cd. When the emphasis on the mass fraction of Zn and Cr, the pyrolysis temperature maintained at lower temperatures should be paid special attention.
(3)At the same temperature, the mass fractions of metals in the residues were related to their boiling points. The lower the boiling point of the heavy metal has the lower mass fraction it occupies.
(4) The impact of temperature on Gr and Cu is larger, high temperature is cause volatilize of Cr and reduce the mass fraction, and should pay attention to maintaining the low temperature.
实验采用自制的热解设备对RDF进行热解,分别用王水,HNO_3/HClO_4进行消解,并用火焰原子吸收分光光度仪和电感耦合等离子发射光谱仪测定了每次实验中残渣中重金属Cu、Pb、Cd、Cr和重金属Zn的含量,分析了不同温度、氧含量、水蒸气条件对金属迁移的影响。
研究结果表明:
(1)随着温度的升高和氧含量的增加,金属在残渣中的残留量降低。
(2)金属Cu和Pb在通入氧气的情况下,随着温度的升高,氧气的氧化性逐渐增强,并呈现线性关系;金属Cd在900℃左右,在残渣中的残留量相对800℃时差别不大,说明升高温度也不会对减少Cd的残留量产生太大影响。而Zn和Cr的趋势与Cd相反,当强调Zn和Cr在残渣中残留量时,应该特别注意将热解温度保持在较低的温度。
(3)相同温度条件下,金属的沸点越低,残留量越少。
(4) Cr和Cu受温度的影响较大,高温将促进Cr和Cu的挥发,减少其在残渣中残留量,因此应该着重注意将热解温度保持在较低的温度。
With the expansion of the cities, municipal solid waste production is increasing in China and over the world. Using refuse derived fuels instead of traditional fuels are gradually be an important subject, and pyrolysis technology has great advantages than incineration technology in municipal solid waste disposing. RDF technology and pyrolysis technology are combined to dispose the solid waste. A pyrolysis apparatus was designed and manufactured for pyrolysis of RDF. The pyrolysis residues were digested using qua fortis, HNO_3 / HCIO_4 respectively. The heavy metal contents including Cu, Pb, Cd, Cr and Zn in the residues were measured by flame atomic absorption spectrophotometer and inductively coupled plasma-atomic emission spectrometry.
The effects of temperature and oxygen concentration on the amounts of heavy metal contents in the residues were investigated. It was found that:
(l)The heavy metal contents in the residues decreased with increasing pyrolysis temperature and increasing oxygen content.
(2) When oxygen exists, Cu and Pb with increasing temperature, oxygen oxidation gradually increased, and showed a linear relationship; the mass fraction of Cd at 900°C is the same as the mass fraction at 800°C The mining is high temperature has little impact to Cd. When the emphasis on the mass fraction of Zn and Cr, the pyrolysis temperature maintained at lower temperatures should be paid special attention.
(3)At the same temperature, the mass fractions of metals in the residues were related to their boiling points. The lower the boiling point of the heavy metal has the lower mass fraction it occupies.
(4) The impact of temperature on Gr and Cu is larger, high temperature is cause volatilize of Cr and reduce the mass fraction, and should pay attention to maintaining the low temperature.
引文
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2.张启德,王玉秀.辽宁省环境问题的研究[M],北京,化学工业出版社,1985,81-84.
3.温俊明.城市生活垃圾热解特性试验研究及预测模型[D],浙江:浙江大学,2006.
4.吴旺明.城市生活垃圾快速热解特性的研究[D],浙江:浙江大学,2005.
5.王艳,牛宝莲等.城市固体垃圾热解设备与特征研究[J],华中科技大学学报,2007(35):99-104.
6.赵明举.煤与垃圾衍生燃料(RDF)的流化床混烧研究及其酸性气体的脱除[D],山西:太原理工大学,2002.
7.王建龙,文湘华.现代环境生物技术[M],北京:清华大学出版社,2001,10:222-228,273-274.
8.万云.固体废弃物的热解技术研究[D],四川:重庆大学,2004.
9.王杰.城市固体垃圾热解研究[J],河北大学学报,2007(38):93-14.
10.曲金星.水分对城市生活垃圾热解气化特性影响的试验研究[D],浙江:浙江大学,2007.
11.刘晓青.城市生活垃圾热解和燃烧的综合热分析研究[D],辽宁:鞍山科技大学,2006.
12.范秀娟.危险废弃物焚烧重金属固化特性的研究[D],浙江:浙江大学,2007.
13.刘清才,文娟,黎辉款.垃圾焚烧飞灰熔融过程中重金属迁移分布规律的研究[J],黑龙江环境通报,2008,32(4):30-35.
14.侯晓龙,马翔庆等.城市垃圾重金属污染及其治理研究进展[J],环境保护科学,2004,32(4):1-35.
15.宋菲,郭玉文,刘孝义等.镉、锌、铅复合污染的研究[J],环境科学学报,1998,18(1):9-14.
16.何桂华,高连存.模拟酸雨条件下降尘中Cu、Pb、Zn、Cr各形态的溶出和转化研究[J],环境化学,1994,13(5):448-452.
17.黄勇,郭庆荣,任海,等.城市土壤重金属污染研究综述[J],热带地理,2005,25(1): 14-18.
18.罗宇.垃圾焚烧系统中重金属的分配及处理研究[D],重庆:重庆大学,2004.
19.杨雷.水泥工业处理含重金属危险废物的技术研究[D],湖北:武汉理工大学,2005.
20.科学出版社编写组.环境中重金属研究文集[M],北京:科学出版社,1988,76-79.
21.张加权.典型城市生活垃圾组分流化床热解气化特性及反应机理研究[D],浙江:浙江大学,2005.
22.王晓磊.混煤热解燃烧特性的实验研究[D],北京;华北电力大学,2005.
23.陈静.医疗垃圾的热解研究[D],天津:天津大学,2005.
24.中国国家标准汇编[M],北京:中国标准出版社,1996,124-126.
25.解强,赵由才,边炳鑫.城市固体废弃物能源利用技术[M],北京:化学工业出版社,2004,5:30-32.
26.锁志文.中国城市生活垃圾的现状及对策[J],环境保护,1997(4):46-50.
27.李新国,李丽梅,周欣,等.垃圾混合物和废塑料热解的实验研究[J],煤气与热力,2005,25(7):9-13.
28.赵由才.生活垃圾资源化原理与技术[M],北京:化学工业出版社,2002,1:8-9.
29.Kjell E.,Haugsten B.G..Environmental properties of vitrified fly ash from hazardous and municipal waste incineration[J],Waste Management,2000(20):167-176.
30.Sheng C,Azevedo J.L.T..Estimating the higher heating value of biomass fuels from basic analysis data[J],Biomass and Bioeh,2005,28(5):499-507.
31.宋宇等.城市固体废弃物污染治理范式[M],北京:环境出版社,2008,37.
32.Wu C,et al.Thermal treatment of coated printing and writing paper in MSW[J],Fuel,1997,76(12):1151-1157.
33.王守信.环境污染控制工程[M],北京:冶金工业出版社,2004,407.
34.Berenyi,E.B..The status of municipal waste combustion in the United States[J],Journal of Hazardous Material,1996(47):1-17.
35.王绍文,梁富智,王纪曾.固体废弃物资源化技术与应用[M],北京:冶金工业出版社,2003:456-478,34-45.
36.Saffarzadeh,A.,et aI.Chemical and mineralogical evaluation of slag products derived from the pyrolysis/melting treatment of MSW[J],Waste Management, 2006,26(12):1443-1452.
37.Malkow,T.Novel and innovative pyrolysis and gasification technologies for energy efficient and environmentally sound MSW disposal[J],Waste Management,2004,24(1):53-79.
38.赵由才,牛冬杰,柴晓利.固体废弃物处理与资源化[M],北京:化学工业出版社,2006,2:216-217,228-231.
39.王树.现代仪器分析[M],北京:化学工业出版社,2000,10:212-223,273-284.
2.张启德,王玉秀.辽宁省环境问题的研究[M],北京,化学工业出版社,1985,81-84.
3.温俊明.城市生活垃圾热解特性试验研究及预测模型[D],浙江:浙江大学,2006.
4.吴旺明.城市生活垃圾快速热解特性的研究[D],浙江:浙江大学,2005.
5.王艳,牛宝莲等.城市固体垃圾热解设备与特征研究[J],华中科技大学学报,2007(35):99-104.
6.赵明举.煤与垃圾衍生燃料(RDF)的流化床混烧研究及其酸性气体的脱除[D],山西:太原理工大学,2002.
7.王建龙,文湘华.现代环境生物技术[M],北京:清华大学出版社,2001,10:222-228,273-274.
8.万云.固体废弃物的热解技术研究[D],四川:重庆大学,2004.
9.王杰.城市固体垃圾热解研究[J],河北大学学报,2007(38):93-14.
10.曲金星.水分对城市生活垃圾热解气化特性影响的试验研究[D],浙江:浙江大学,2007.
11.刘晓青.城市生活垃圾热解和燃烧的综合热分析研究[D],辽宁:鞍山科技大学,2006.
12.范秀娟.危险废弃物焚烧重金属固化特性的研究[D],浙江:浙江大学,2007.
13.刘清才,文娟,黎辉款.垃圾焚烧飞灰熔融过程中重金属迁移分布规律的研究[J],黑龙江环境通报,2008,32(4):30-35.
14.侯晓龙,马翔庆等.城市垃圾重金属污染及其治理研究进展[J],环境保护科学,2004,32(4):1-35.
15.宋菲,郭玉文,刘孝义等.镉、锌、铅复合污染的研究[J],环境科学学报,1998,18(1):9-14.
16.何桂华,高连存.模拟酸雨条件下降尘中Cu、Pb、Zn、Cr各形态的溶出和转化研究[J],环境化学,1994,13(5):448-452.
17.黄勇,郭庆荣,任海,等.城市土壤重金属污染研究综述[J],热带地理,2005,25(1): 14-18.
18.罗宇.垃圾焚烧系统中重金属的分配及处理研究[D],重庆:重庆大学,2004.
19.杨雷.水泥工业处理含重金属危险废物的技术研究[D],湖北:武汉理工大学,2005.
20.科学出版社编写组.环境中重金属研究文集[M],北京:科学出版社,1988,76-79.
21.张加权.典型城市生活垃圾组分流化床热解气化特性及反应机理研究[D],浙江:浙江大学,2005.
22.王晓磊.混煤热解燃烧特性的实验研究[D],北京;华北电力大学,2005.
23.陈静.医疗垃圾的热解研究[D],天津:天津大学,2005.
24.中国国家标准汇编[M],北京:中国标准出版社,1996,124-126.
25.解强,赵由才,边炳鑫.城市固体废弃物能源利用技术[M],北京:化学工业出版社,2004,5:30-32.
26.锁志文.中国城市生活垃圾的现状及对策[J],环境保护,1997(4):46-50.
27.李新国,李丽梅,周欣,等.垃圾混合物和废塑料热解的实验研究[J],煤气与热力,2005,25(7):9-13.
28.赵由才.生活垃圾资源化原理与技术[M],北京:化学工业出版社,2002,1:8-9.
29.Kjell E.,Haugsten B.G..Environmental properties of vitrified fly ash from hazardous and municipal waste incineration[J],Waste Management,2000(20):167-176.
30.Sheng C,Azevedo J.L.T..Estimating the higher heating value of biomass fuels from basic analysis data[J],Biomass and Bioeh,2005,28(5):499-507.
31.宋宇等.城市固体废弃物污染治理范式[M],北京:环境出版社,2008,37.
32.Wu C,et al.Thermal treatment of coated printing and writing paper in MSW[J],Fuel,1997,76(12):1151-1157.
33.王守信.环境污染控制工程[M],北京:冶金工业出版社,2004,407.
34.Berenyi,E.B..The status of municipal waste combustion in the United States[J],Journal of Hazardous Material,1996(47):1-17.
35.王绍文,梁富智,王纪曾.固体废弃物资源化技术与应用[M],北京:冶金工业出版社,2003:456-478,34-45.
36.Saffarzadeh,A.,et aI.Chemical and mineralogical evaluation of slag products derived from the pyrolysis/melting treatment of MSW[J],Waste Management, 2006,26(12):1443-1452.
37.Malkow,T.Novel and innovative pyrolysis and gasification technologies for energy efficient and environmentally sound MSW disposal[J],Waste Management,2004,24(1):53-79.
38.赵由才,牛冬杰,柴晓利.固体废弃物处理与资源化[M],北京:化学工业出版社,2006,2:216-217,228-231.
39.王树.现代仪器分析[M],北京:化学工业出版社,2000,10:212-223,273-284.