调理剂Fenton/CaO对深度脱水市政污泥燃烧特性的影响
|
摘要
采用超高压板框压滤法进行污泥脱水,制备了3种Fenton/Ca O调理的深度脱水污泥.同时,利用热重分析仪(TG/DTG)研究了Fenton/Ca O投加量和升温速率对深度脱水市政污泥燃烧特性的影响,获得其燃烧特性指数,并建立了燃烧动力学方程.研究表明,Fenton/Ca O调理污泥燃烧过程中有3个失重阶段:水分的析出、挥发分的析出与燃烧、部分挥发分与固定碳的燃尽.与原泥(S1)对比研究可知,调理污泥S2(调理剂折算量Fe2+/H2O2/Ca2+=30/30/70 mg·g-1DS)、S3(调理剂折算量Fe2+/H2O2/Ca2+=50/30/100 mg·g-1DS)的燃尽指数Cb较小,S4(调理剂折算量Fe2+/H2O2/Ca2+=70/30/120 mg·g-1DS)的燃尽指数Cb较大,说明调理剂投加较多时(S4)有利于污泥的燃尽.而3种调理污泥的挥发分释放特性指数D分别增大为原泥的1.10、1.97、1.73倍,可燃性指数C及综合燃烧特性指数S分别降低为原泥的78%~95%、52%~75%,说明增加调理剂用量提升了污泥的初期燃尽率,却降低了污泥的整体燃烧性能.调理污泥的对比研究可知,S3的燃烧特性指数(D、C、S)最大,说明适量的调理剂投加(S3)能在调理污泥中获得最佳的燃烧性能.利用Ozawz-Flynn-Wall法和Kissinger-Akahira-Sunose法计算得到原泥S1及调理污泥(S2、S3、S4)燃烧的质量平均表观活化能,发现调理后污泥的质量平均表观活化能Em1(阶段Ⅰ)下降,但Em2(阶段Ⅱ)提高,整体活化能Em下降;S3获得最低的Em.
Sewage sludge was conditioned with Fenton's reagent/lime in three different dosages and then dewatered through the ultrahigh pressure filtration system. Effects of Fenton/Ca O dosage and heating rate on the combustion characteristics of deeply dewatered sewage sludge were investigated by thermogravimetric analysis( TG-DTG). Then the parameters of combustion kinetics was calculated and the kinetic equation of each sludges sample wasestablished. The results show that three degradation stages,i.e. dehydration,combustion of volatile and combustion of the fixed carbon were identified in the combustion process of the conditioned sludge. Compared with raw sludge,burnout index Cbof S2( conditioned at a dosage of Fe2+/H2 O2/Ca2+= 30/30/70 mg·g-1 dry solids) and S3( conditioned at a dosage of Fe2+/H2 O2/Ca2+= 50/30/100 mg·g-1 dry solids) decreased slightly,while Cb of S4(conditioned at a dosage of Fe2+/H2 O2/Ca2+= 70/30/120 mg·g-1 dry solids) increased,which implies that higher dosage( S4) is helpful for the burnout of sludge. Volatile releasing index D of three conditioned sludge increased by 1. 10,1. 97,1. 73 times respectively,which indicates that conditioning with Fenton/Ca O is helpful for the initial combustion of sludge. However,flammability index C and the comprehensive combustion index S decreased respectively by 0. 78 ~ 0. 95 and 0. 52 ~ 0. 75 times,indicating that sludge conditioning with Fenton/Ca O reduces the overall combustion performance of sludge. Among three conditioned sludges,the combustion characteristics( D,C,S) of S3 were the highest,indicating that an appropriate dosage for sludge conditioning was favorable for combustion. The mass average apparent activation energies( Em) of sewage sewage and three conditioned sludges were calculated with Ozawz-Flynn-Wall method and Kissinger-Akahira-Sunose method. It is found that,compared with raw sludge,Em of conditioned sludges during stage Ⅰ( Em1) decreased,while increased during stage Ⅱ( Em2). Overall,Em during the whole combustion process decreased,and Emof S3 was the lowest among conditioned sludges.
Sewage sludge was conditioned with Fenton's reagent/lime in three different dosages and then dewatered through the ultrahigh pressure filtration system. Effects of Fenton/Ca O dosage and heating rate on the combustion characteristics of deeply dewatered sewage sludge were investigated by thermogravimetric analysis( TG-DTG). Then the parameters of combustion kinetics was calculated and the kinetic equation of each sludges sample wasestablished. The results show that three degradation stages,i.e. dehydration,combustion of volatile and combustion of the fixed carbon were identified in the combustion process of the conditioned sludge. Compared with raw sludge,burnout index Cbof S2( conditioned at a dosage of Fe2+/H2 O2/Ca2+= 30/30/70 mg·g-1 dry solids) and S3( conditioned at a dosage of Fe2+/H2 O2/Ca2+= 50/30/100 mg·g-1 dry solids) decreased slightly,while Cb of S4(conditioned at a dosage of Fe2+/H2 O2/Ca2+= 70/30/120 mg·g-1 dry solids) increased,which implies that higher dosage( S4) is helpful for the burnout of sludge. Volatile releasing index D of three conditioned sludge increased by 1. 10,1. 97,1. 73 times respectively,which indicates that conditioning with Fenton/Ca O is helpful for the initial combustion of sludge. However,flammability index C and the comprehensive combustion index S decreased respectively by 0. 78 ~ 0. 95 and 0. 52 ~ 0. 75 times,indicating that sludge conditioning with Fenton/Ca O reduces the overall combustion performance of sludge. Among three conditioned sludges,the combustion characteristics( D,C,S) of S3 were the highest,indicating that an appropriate dosage for sludge conditioning was favorable for combustion. The mass average apparent activation energies( Em) of sewage sewage and three conditioned sludges were calculated with Ozawz-Flynn-Wall method and Kissinger-Akahira-Sunose method. It is found that,compared with raw sludge,Em of conditioned sludges during stage Ⅰ( Em1) decreased,while increased during stage Ⅱ( Em2). Overall,Em during the whole combustion process decreased,and Emof S3 was the lowest among conditioned sludges.
引文
陈建原,孙学信.1987.煤的挥发分释放特性指数及燃烧特性指数的确定[J].动力工程,7(5):13-18
Citeau M,Larue O,Vorobiev E.2011.Influence of salt,p H and polyelectrolyte on the pressure electro-dewatering of sewage sludge[J].Water Research,45:2167-80
Cumming J W.1984.Reactivity assessment of coals via a weighted mean activation energy[J].Fuel,63(10):1436-1440
Czechowski F,Marcinkowski T.2006.Sewage sludge stabilisation with calcium hydroxide:Effect on physicochemical properties and molecular composition[J].Water Research,40(9):1895-1905
Deng W,Yan J,Li X,et al.2009.Emission characteristics of volatile compounds during sludges drying process[J].Journal of Hazardous Materials,162(1):186-192
高鑫,李玲,杨东伟,等.2015.石灰调质污泥的燃烧特性及动力学分析[J].环境工程学报,9(6):3019-3023
Ga2parovièL.2012.Calculation of kinetic parameters of the thermal decomposition of wood by distributed activation energy model(DAEM)[J].Chemical and Biochemical Engineering Quarterly,26:45-53
胡勤海,熊云龙,朱妙军,等.2008.城市污泥掺制水煤浆燃烧动力学特性[J].环境科学学报,28(6):1149-1154
Huang L,Liu J,He Y,et al.2016.Thermodynamics and kinetics parameters of co-combustion between sewage sludge and water hyacinth in CO2/O2atmosphere as biomass to solid biofuel[J].Bioresource Technolog,218:631-642
黄绍松,梁嘉林,张斯玮,等.2018.Fenton氧化联合氧化钙调理对污泥脱水的机理研究[J].环境科学学报,38(5):1906-1919
Jiang L,Yuan X,Li H,et al.2015.Pyrolysis and combustion kinetics of sludge-camphor pellet thermal decomposition using thermogravimetric analysis[J].Energy Conversion and Management,106:282-289
Liang J,Huang S,Dai Y,et al.2015.Dewaterability of five sewage sludges in Guangzhou conditioned with Fenton's reagent/lime and pilot-scale experiments using ultrahigh pressure filtration system[J].Water Research,84:243-254
Liu H,Liu P,Hu H,et al.2014.Combined effects of Fenton peroxidation and Ca O conditioning on sewage sludge thermal drying[J].Chemosphere,117:559-566
Liu H,Yang J,Zhu N,et al.2013.A comprehensive insight into the combined effects of Fenton's reagent and skeleton builders on sludge deep dewatering performance[J].Journal of Hazardous Materials,258:144-150
Liu H,Zhang Q,Xing H,et al.2015.Product distribution and sulfur behavior in sewage sludge pyrolysis:Synergistic effect of Fenton peroxidation and Ca O conditioning[J].Fuel,159:68-75
刘敬勇,傅杰文,孙水裕,等.2016.不同来源污泥混燃特性及其综合燃烧性能评价[J].环境科学学报,36(3):940-952
Liu S,Wei M M,Qiao Y,et al.2015.Release of organic sulfur as sulfurcontaining gases during low temperature pyrolysis of sewage sludge[J].Proceedings of the Combustion Institute,35(3):2767-2775
聂其红,孙绍增,李争起,等.2001.褐煤混煤燃烧特性的热重分析法研究[J].燃烧科学与技术,7(1):72-76
Nowicki L,Ledakowicz S.2014.Comprehensive characterization of thermal decomposition of sewage sludge by TG-MS[J].Journal of Analytical and Applied Pyrolysis,110:220-228
Qi Y,Thapa K B,Hoadley A F A.2011.Application of filtration aids for improving sludge dewatering properties e a review[J].Chemica Engineering Journal,171:373-384
Shao J,Yan R,Chen H,et al.2010.Catalytic effect of metal oxides on pyrolysis of sewage sludge[J].Fuel Processing Technology,91(9):1113-1118
Shen B X,Liu D C,Lu J D.2000.Study on ignition and combustion o petroleum coke[J].Petroleum Processing and Petrochemical,3(10):60-64
Tyagi V K,Lo S.2013.Sludge:A waste or renewable source for energy and resources recovery?[J].Renewable and Sustainable Energy Reviews,25:708-728
Xu Y,Chen B.2013.Investigation of thermodynamic parameters in the pyrolysis conversion of biomass and manure to biochars using thermogravimetric analysis[J].Bioresource Technology,146:485-493
曾佳俊,孙水裕,陈楠纬,等.2015.调理剂Fe Cl3/Ca O对深度脱水市政污泥燃烧特性的影响[J].环境科学学报,35(6):1842-1850
曾武勇,金晶,张号,等.2013.两种典型污泥热解特性及动力学机理[J].燃烧科学与技术,19(6):544-548
张强,邢智炜,刘欢,等.2013.不同深度脱水污泥的热解特性及动力学分析[J].环境化学,32(5):839-846
郑蕾,田禹,孙德智,等.2007.p H值对活性污泥胞外聚合物分子结构和表面特征影响研究[J].环境科学,28(7):1507-1511
Zhou C,Liu G,Cheng S,et al.2014.Thermochemical and trace element behavior of coal gangue,agricultural biomass and their blends during cocombustion.Bioresource Technology;166:243-251
周宏仓,徐露,周云桥,等.2013.过量生石灰对污泥含水率和有机物量的影响[J].环境工程学报,7(2):717-721
Citeau M,Larue O,Vorobiev E.2011.Influence of salt,p H and polyelectrolyte on the pressure electro-dewatering of sewage sludge[J].Water Research,45:2167-80
Cumming J W.1984.Reactivity assessment of coals via a weighted mean activation energy[J].Fuel,63(10):1436-1440
Czechowski F,Marcinkowski T.2006.Sewage sludge stabilisation with calcium hydroxide:Effect on physicochemical properties and molecular composition[J].Water Research,40(9):1895-1905
Deng W,Yan J,Li X,et al.2009.Emission characteristics of volatile compounds during sludges drying process[J].Journal of Hazardous Materials,162(1):186-192
高鑫,李玲,杨东伟,等.2015.石灰调质污泥的燃烧特性及动力学分析[J].环境工程学报,9(6):3019-3023
Ga2parovièL.2012.Calculation of kinetic parameters of the thermal decomposition of wood by distributed activation energy model(DAEM)[J].Chemical and Biochemical Engineering Quarterly,26:45-53
胡勤海,熊云龙,朱妙军,等.2008.城市污泥掺制水煤浆燃烧动力学特性[J].环境科学学报,28(6):1149-1154
Huang L,Liu J,He Y,et al.2016.Thermodynamics and kinetics parameters of co-combustion between sewage sludge and water hyacinth in CO2/O2atmosphere as biomass to solid biofuel[J].Bioresource Technolog,218:631-642
黄绍松,梁嘉林,张斯玮,等.2018.Fenton氧化联合氧化钙调理对污泥脱水的机理研究[J].环境科学学报,38(5):1906-1919
Jiang L,Yuan X,Li H,et al.2015.Pyrolysis and combustion kinetics of sludge-camphor pellet thermal decomposition using thermogravimetric analysis[J].Energy Conversion and Management,106:282-289
Liang J,Huang S,Dai Y,et al.2015.Dewaterability of five sewage sludges in Guangzhou conditioned with Fenton's reagent/lime and pilot-scale experiments using ultrahigh pressure filtration system[J].Water Research,84:243-254
Liu H,Liu P,Hu H,et al.2014.Combined effects of Fenton peroxidation and Ca O conditioning on sewage sludge thermal drying[J].Chemosphere,117:559-566
Liu H,Yang J,Zhu N,et al.2013.A comprehensive insight into the combined effects of Fenton's reagent and skeleton builders on sludge deep dewatering performance[J].Journal of Hazardous Materials,258:144-150
Liu H,Zhang Q,Xing H,et al.2015.Product distribution and sulfur behavior in sewage sludge pyrolysis:Synergistic effect of Fenton peroxidation and Ca O conditioning[J].Fuel,159:68-75
刘敬勇,傅杰文,孙水裕,等.2016.不同来源污泥混燃特性及其综合燃烧性能评价[J].环境科学学报,36(3):940-952
Liu S,Wei M M,Qiao Y,et al.2015.Release of organic sulfur as sulfurcontaining gases during low temperature pyrolysis of sewage sludge[J].Proceedings of the Combustion Institute,35(3):2767-2775
聂其红,孙绍增,李争起,等.2001.褐煤混煤燃烧特性的热重分析法研究[J].燃烧科学与技术,7(1):72-76
Nowicki L,Ledakowicz S.2014.Comprehensive characterization of thermal decomposition of sewage sludge by TG-MS[J].Journal of Analytical and Applied Pyrolysis,110:220-228
Qi Y,Thapa K B,Hoadley A F A.2011.Application of filtration aids for improving sludge dewatering properties e a review[J].Chemica Engineering Journal,171:373-384
Shao J,Yan R,Chen H,et al.2010.Catalytic effect of metal oxides on pyrolysis of sewage sludge[J].Fuel Processing Technology,91(9):1113-1118
Shen B X,Liu D C,Lu J D.2000.Study on ignition and combustion o petroleum coke[J].Petroleum Processing and Petrochemical,3(10):60-64
Tyagi V K,Lo S.2013.Sludge:A waste or renewable source for energy and resources recovery?[J].Renewable and Sustainable Energy Reviews,25:708-728
Xu Y,Chen B.2013.Investigation of thermodynamic parameters in the pyrolysis conversion of biomass and manure to biochars using thermogravimetric analysis[J].Bioresource Technology,146:485-493
曾佳俊,孙水裕,陈楠纬,等.2015.调理剂Fe Cl3/Ca O对深度脱水市政污泥燃烧特性的影响[J].环境科学学报,35(6):1842-1850
曾武勇,金晶,张号,等.2013.两种典型污泥热解特性及动力学机理[J].燃烧科学与技术,19(6):544-548
张强,邢智炜,刘欢,等.2013.不同深度脱水污泥的热解特性及动力学分析[J].环境化学,32(5):839-846
郑蕾,田禹,孙德智,等.2007.p H值对活性污泥胞外聚合物分子结构和表面特征影响研究[J].环境科学,28(7):1507-1511
Zhou C,Liu G,Cheng S,et al.2014.Thermochemical and trace element behavior of coal gangue,agricultural biomass and their blends during cocombustion.Bioresource Technology;166:243-251
周宏仓,徐露,周云桥,等.2013.过量生石灰对污泥含水率和有机物量的影响[J].环境工程学报,7(2):717-721