生物反应器模拟生活垃圾填埋降解产甲烷性能
|
摘要
该文采用生物反应器模拟生活垃圾填埋降解过程,跟踪测试了垃圾在厌氧消化过程中产甲烷进程及渗滤液特性,并探索两者之间的关系,旨在筛选出可以预测垃圾厌氧消化产甲烷进程的指标。结果表明渗滤液pH值、TOC/TN(total organic carbon/total nitrogen)、乙酸/戊酸(HAc/HVa)的变化对系统产甲烷进程及稳定性有一定的指示作用。消化系统产甲烷初期,渗滤液pH值稳定在5.77~5.91。产甲烷高峰期,渗滤液pH值会迅速升高达到峰值。渗滤液中TOC/TN≥11时,垃圾厌氧发酵系统稳定,产甲烷正常。而当渗滤液中TOC/TN<11时,发酵系统因氨积累失稳,产气量小。戊酸在垃圾厌氧消化过程中生成与转化较为活跃,HAc/HVa变化较大且有明显的拐点,拐点处可预测消化系统进入产甲烷期。此外,采用16S r RNA基因标记技术对反应器中3个阶段的垃圾渗滤液样品(水解酸化期A、产甲烷高峰期B、产甲烷末期C)以及试验结束时垃圾样品和覆盖土样品进行群落评估。聚类树分析得出生活垃圾(municipal solid wastes,MSW)样品与渗滤液样品其微生物种类及丰度都较为接近,有较近的亲缘关系,且反应期越长相似度越高。测定渗滤液样品的微生物群落组成可一定程度反映出系统内垃圾的群落结构。覆盖层是系统进行硝化反应的主要场所。垃圾厌氧消化末期,系统中氨积累抑制产甲烷菌活性,是导致系统产甲烷能力下降的主要原因。
In this paper, bioreactor was used to simulate the municipal solid waste(MSW) biodegradation process of landfill, tracing and testing trash methanogenic process and characteristics of leachate during anaerobic digestion, exploring the relationship between the two processes, aiming to screen out the indicators that can predict the methane production process of anaerobic digestion. The results observed at the end of 250 days prevailed that the cumulative biogas production was 1 850.38 L. The MSW anaerobic digestion gas production rate exponentially declines, measured values were basically consistent with the curve fitting with 0.78 of correlation coefficient. The nonlinear regression of the biogas production rates and digestion time showed that Scholl Canyon model fitted the results well, and the biogas production rate constants and waste gas potential were 0.0149 d-1 and 66.36 L/kg, respectively. Determination of leachate characteristics showed that the peaks of total organic carbon(TOC) concentration in leachate appeared two times, which corresponded to the hydrolysis of sugar and protein in MSW. The concentration of TN in leachate continued to increase, showing the trend of nitrogen accumulation. The pH value, total organic carbon/total nitrogen(TOC/TN), acetic acid/valeric acid(HAc/HVa) of leachate changed in the system of methane production process, which has some instructions for stability. At the initial stage of methane production from digestive system, the pH value of leachate stabilized at 5.77-5.91. During the peak of methanogenic period, the pH value of leachate rapidly rose to its peak. In the late stage of methane production, the pH value continued to decrease and was less than 5.8. When the TOC/TN value of leachate was larger than 11, the anaerobic fermentation system was stable and methanogenic was normal. However, when TOC/TN value of leachate was lower than 11, the fermentation system was unstable due to ammonia accumulation, biogas production was small. The concentration of volatile fatty acids in leachate was HBu>HAc>HPr>HVa during the test period. The synthesis and transformation of valerate in waste anaerobic digestion process was relatively active. The HAc/HVa ratio changed greatly and had a significant inflection point, which was corresponding to the initial stage of methane production by anaerobic digestion. In addition, this paper also studied the leachate samples from different reaction periods(hydrolytic acidification A(50 th day), methane production peak B(190 th day), methane production end C(250 th)), and solid samples at end-state MSW and cover were analyzed by 16 S r RNA gene tag pyrosequencing for microbial community assessment. Cluster tree analysis showed that MSW samples and leachate samples were relatively close in microbial species and abundance with close genetic relationship, and the longer the reaction period, the higher the similarity. The lack of Nitrospira in the anaerobic digestion system led to the interruption of ammonia nitrogen/nitrate/nitrite cycle, which caused environmental degradation and was not conducive to system gas production. The cover layer was the main site of nitrification. The cover layer can be used as a biochemical reaction active layer, which can promote methane production in the anaerobic digestion system. The ammonia poisoning inhibited the activity of methanogenic bacteria, which was the main reason for the decrease of methane production capacity of the anaerobic digestion system. The inoculation of Nitrospira biological bacteria in the phase of MSW oxygen consumption can strengthen the NH3-N nitrification reaction at the initial stage of waste fermentation, reduce the accumulation of ammonia in the late digestive system and enhance the stability of the MSW anaerobic digestion.
In this paper, bioreactor was used to simulate the municipal solid waste(MSW) biodegradation process of landfill, tracing and testing trash methanogenic process and characteristics of leachate during anaerobic digestion, exploring the relationship between the two processes, aiming to screen out the indicators that can predict the methane production process of anaerobic digestion. The results observed at the end of 250 days prevailed that the cumulative biogas production was 1 850.38 L. The MSW anaerobic digestion gas production rate exponentially declines, measured values were basically consistent with the curve fitting with 0.78 of correlation coefficient. The nonlinear regression of the biogas production rates and digestion time showed that Scholl Canyon model fitted the results well, and the biogas production rate constants and waste gas potential were 0.0149 d-1 and 66.36 L/kg, respectively. Determination of leachate characteristics showed that the peaks of total organic carbon(TOC) concentration in leachate appeared two times, which corresponded to the hydrolysis of sugar and protein in MSW. The concentration of TN in leachate continued to increase, showing the trend of nitrogen accumulation. The pH value, total organic carbon/total nitrogen(TOC/TN), acetic acid/valeric acid(HAc/HVa) of leachate changed in the system of methane production process, which has some instructions for stability. At the initial stage of methane production from digestive system, the pH value of leachate stabilized at 5.77-5.91. During the peak of methanogenic period, the pH value of leachate rapidly rose to its peak. In the late stage of methane production, the pH value continued to decrease and was less than 5.8. When the TOC/TN value of leachate was larger than 11, the anaerobic fermentation system was stable and methanogenic was normal. However, when TOC/TN value of leachate was lower than 11, the fermentation system was unstable due to ammonia accumulation, biogas production was small. The concentration of volatile fatty acids in leachate was HBu>HAc>HPr>HVa during the test period. The synthesis and transformation of valerate in waste anaerobic digestion process was relatively active. The HAc/HVa ratio changed greatly and had a significant inflection point, which was corresponding to the initial stage of methane production by anaerobic digestion. In addition, this paper also studied the leachate samples from different reaction periods(hydrolytic acidification A(50 th day), methane production peak B(190 th day), methane production end C(250 th)), and solid samples at end-state MSW and cover were analyzed by 16 S r RNA gene tag pyrosequencing for microbial community assessment. Cluster tree analysis showed that MSW samples and leachate samples were relatively close in microbial species and abundance with close genetic relationship, and the longer the reaction period, the higher the similarity. The lack of Nitrospira in the anaerobic digestion system led to the interruption of ammonia nitrogen/nitrate/nitrite cycle, which caused environmental degradation and was not conducive to system gas production. The cover layer was the main site of nitrification. The cover layer can be used as a biochemical reaction active layer, which can promote methane production in the anaerobic digestion system. The ammonia poisoning inhibited the activity of methanogenic bacteria, which was the main reason for the decrease of methane production capacity of the anaerobic digestion system. The inoculation of Nitrospira biological bacteria in the phase of MSW oxygen consumption can strengthen the NH3-N nitrification reaction at the initial stage of waste fermentation, reduce the accumulation of ammonia in the late digestive system and enhance the stability of the MSW anaerobic digestion.
引文
[1]Comparetti A,Febo P,Greco C,et al.Italian potential biogas and biomethane production from of MSW[C]//IV International Conference Ragusa Shwa"safety,Health and Welfare in Agriculture,Agro-Food and Forestry Systems.2015.
[2]Di M F,Gigliotti G,Sordi A,et al.Hybrid solid anaerobic digestion batch:biomethane production and mass recovery from the organic fraction of solid waste[J].Waste Manag Res,2013,31(8):869-873.
[3]Aydi A,Abichou T,Zairi M,et al.Assessment of electrical generation potential and viability of gas collection from fugitive emissions in a Tunisian landfill[J].Energy Strategy Reviews,2015,8:8-14.
[4]Yu L,Wensel P C,Ma J W,et al.Mathematical modeling in anaerobic digestion(AD)[J].Journal of Bioremediation and Biodegradation,2014,5(S4):S4-003.
[5]Aguilar-Virgen Q,Taboada-González P,Ojeda-Benítez S.Analysis of the feasibility of the recovery of landfill gas:A case study of Mexico[J].Journal of Cleaner Production,2014,79:53-60.
[6]杨国栋,蒋建国,黄云峰,等.渗滤液回灌负荷对填埋场垃圾产气效能的影响[J].环境科学,2006,27(10):2129-2134.Yang Guodong,Jiang Juangu,Huang Yunfeng,et al.[Impact of leachate recirculation loadings on efficiency of landfill gas(LFG)generation][J].Environmental Science,2006,27(10):2129-2134.(in Chinese with English abstract)
[7]Townsend T G,Miller W L,Lee H,et al.Acceleration of landfill stabilization using leachate recycle[J].Journal of Environmental Engineering,1996,122(4):263-268.
[8]Wang Y,Pelkonen M.Impacts of temperature and liquid/solid ratio on anaerobic degradation of municipal solid waste:an emission investigation of landfill simulation reactors[J].Journal of Material Cycles and Waste Management,2009,11(4):312-320.
[9]Nikolaou A,Giannis A,Gidarakos E.Comparative studies of aerobic and anaerobic treatment of MSW organic fraction in landfill bioreactors.[J].Environmental Technology,2010,31(12):1381-1389.
[10]Reinhart D R,Mccreanor P T,Townsend T.The bioreactor landfill:its status and future[J].Waste Management&Research,2002,20(2):172-186.
[11]Sakita S,Nishimoto J,Nishimura K.A survey on characteristics of leachate pond in an offshore municipal solid waste disposal site[J].Journal of Material Cycles&Waste Management,2016,18(2):348-355.
[12]Arjun N.Effect of Leachate Blending on Anaerobic Digestion of Organic Fraction of Municipal Solid Waste[D].Ottawa:University of Ottawa,2013.
[13]Moletta R,Escoffier Y,Ehlinger F,et al.On-line automatic control system for monitoring an anaerobic fluidized-bed reactor:response to organic overload[J].Water Science&Technology,1994,30(12):11-20.
[14]Ahring B K,Sandberg M,Angelidaki I.Volatile fatty acids as indicators of process imbalance in anaerobic digestors[J].Applied Microbiology&Biotechnology,1995,43(3):559-565.
[15]陈琳,李东,文昊深,等.蔬菜废弃物中温厌氧发酵酸化失稳预警指标筛选[J].农业工程学报,2017,33(1):225-230.Chen Lin,Li Dong,Wen Haosen,et al.Screening of early warning indicators of instability in anaerobic digestion of vegetable waste under mesophilic condition[J].Transactions of the Chinese Society of Agricultural Engineering(Transactions of the CSAE),2017,33(1):225-230.(in Chinese with English abstract)
[16]Zhang B,Deng H,Wang H,et al.Does microbial habitat or community structure drive the functional stability of microbes to stresses following re-vegetation of a severely degraded soil[J].Soil Biology&Biochemistry,2010,42(5):850-859.
[17]焦学军,邵军,杨承休.城市生活垃圾填埋产气规律研究[J].上海环境科学,1996(9):30-33.
[18]Charles W,Carnaje N P,Cordruwisch R.Methane conversion efficiency as a simple control parameter for an anaerobic digester at high loading rates[J].Water Science&Technology,2011,64(2):534-539.
[19]He R,Wei X M,Chen M,et al.Effects of concentrated leachate injection modes on stabilization of landfilled waste[J].Environmental Science&Pollution Research International,2015,23(4):1-9.
[20]Sun Y,Sun X,Zhao Y.Comparison of semi-aerobic and anaerobic degradation of refuse with recirculation after leachate treatment by aged refuse bioreactor[J].Waste Management,2011,31(6):1202-1209.
[21]Sun Y,Sun X,Zhao Y.Comparison of semi-aerobic and anaerobic degradation of refuse with recirculation after leachate treatment by aged refuse bioreactor[J].Waste Management,2011,31(6):1202-1209.
[22]Kayhanian M.Ammonia inhibition in high-solids biogasification:An overview and practical solutions[J].Environmental Technology,1999,20(4):355-365.
[23]Kjeldsen P,Barlaz M A,Rooker A P,et al.Present and Long-Term Composition of MSW Landfill Leachate:A Review[J].Critical Reviews in Environmental Science&Technology,2002,32(4):297-336.
[24]Menkveld H W H,Broeders E.Recovery of ammonium from digestate as fertilizer[J].Water Practice&Technology,2017,12(3):514-519.
[25]Sprott G D,Patel G B.Ammonia toxicity in pure cultures of methanogenic bacteria[J].Systematic&Applied Microbiology,1986,7(2):358-363.
[26]Desloover J,Woldeyohannis A A,Verstraete W,et al.Electrochemical resource recovery from digestate to prevent ammonia toxicity during anaerobic digestion[J].Environmental Science&Technology,2012,46(21):12209-12216.
[27]Wang Y,Zhang Y,Wang J,et al.Effects of volatile fatty acid concentrations on methane yield and methanogenic bacteria[J].Biomass&Bioenergy,2009,33(5):848-853.
[28]Yeole T Y,Gokhale S,Hajarnis S R,et al.Effect of brackish water on biogas production from cattle dung and methanogens[J].Bioresource Technology,1996,58(3):323-325.
[29]Kim B C,Jeon B S,Kim S I,et al.Caproiciproducens galactitolivorans gen.nov.sp.nov.,a bacterium capable of producing caproic acid from galactitol,isolated from a wastewater treatment plant[J].International Journal of Systematic&Evolutionary Microbiology,2015,65(12):4902.
[30]Liu M K,Tang Y M,Guo X J,et al.Deep sequencing reveals high bacterial diversity and phylogenetic novelty in pit mud from Luzhou Laojiao cellars for Chinese strong-flavor Baijiu[J].Food Research International,2017,102:68-72.
[31]Mali Sandip T,Khare Kanchan C,Biradar Ashok H.Enhancement of methane production and bio-stabilisation of municipal solid waste in anaerobic bioreactor landfill[J].Bioresource Technology,2012,110:10-17.
[2]Di M F,Gigliotti G,Sordi A,et al.Hybrid solid anaerobic digestion batch:biomethane production and mass recovery from the organic fraction of solid waste[J].Waste Manag Res,2013,31(8):869-873.
[3]Aydi A,Abichou T,Zairi M,et al.Assessment of electrical generation potential and viability of gas collection from fugitive emissions in a Tunisian landfill[J].Energy Strategy Reviews,2015,8:8-14.
[4]Yu L,Wensel P C,Ma J W,et al.Mathematical modeling in anaerobic digestion(AD)[J].Journal of Bioremediation and Biodegradation,2014,5(S4):S4-003.
[5]Aguilar-Virgen Q,Taboada-González P,Ojeda-Benítez S.Analysis of the feasibility of the recovery of landfill gas:A case study of Mexico[J].Journal of Cleaner Production,2014,79:53-60.
[6]杨国栋,蒋建国,黄云峰,等.渗滤液回灌负荷对填埋场垃圾产气效能的影响[J].环境科学,2006,27(10):2129-2134.Yang Guodong,Jiang Juangu,Huang Yunfeng,et al.[Impact of leachate recirculation loadings on efficiency of landfill gas(LFG)generation][J].Environmental Science,2006,27(10):2129-2134.(in Chinese with English abstract)
[7]Townsend T G,Miller W L,Lee H,et al.Acceleration of landfill stabilization using leachate recycle[J].Journal of Environmental Engineering,1996,122(4):263-268.
[8]Wang Y,Pelkonen M.Impacts of temperature and liquid/solid ratio on anaerobic degradation of municipal solid waste:an emission investigation of landfill simulation reactors[J].Journal of Material Cycles and Waste Management,2009,11(4):312-320.
[9]Nikolaou A,Giannis A,Gidarakos E.Comparative studies of aerobic and anaerobic treatment of MSW organic fraction in landfill bioreactors.[J].Environmental Technology,2010,31(12):1381-1389.
[10]Reinhart D R,Mccreanor P T,Townsend T.The bioreactor landfill:its status and future[J].Waste Management&Research,2002,20(2):172-186.
[11]Sakita S,Nishimoto J,Nishimura K.A survey on characteristics of leachate pond in an offshore municipal solid waste disposal site[J].Journal of Material Cycles&Waste Management,2016,18(2):348-355.
[12]Arjun N.Effect of Leachate Blending on Anaerobic Digestion of Organic Fraction of Municipal Solid Waste[D].Ottawa:University of Ottawa,2013.
[13]Moletta R,Escoffier Y,Ehlinger F,et al.On-line automatic control system for monitoring an anaerobic fluidized-bed reactor:response to organic overload[J].Water Science&Technology,1994,30(12):11-20.
[14]Ahring B K,Sandberg M,Angelidaki I.Volatile fatty acids as indicators of process imbalance in anaerobic digestors[J].Applied Microbiology&Biotechnology,1995,43(3):559-565.
[15]陈琳,李东,文昊深,等.蔬菜废弃物中温厌氧发酵酸化失稳预警指标筛选[J].农业工程学报,2017,33(1):225-230.Chen Lin,Li Dong,Wen Haosen,et al.Screening of early warning indicators of instability in anaerobic digestion of vegetable waste under mesophilic condition[J].Transactions of the Chinese Society of Agricultural Engineering(Transactions of the CSAE),2017,33(1):225-230.(in Chinese with English abstract)
[16]Zhang B,Deng H,Wang H,et al.Does microbial habitat or community structure drive the functional stability of microbes to stresses following re-vegetation of a severely degraded soil[J].Soil Biology&Biochemistry,2010,42(5):850-859.
[17]焦学军,邵军,杨承休.城市生活垃圾填埋产气规律研究[J].上海环境科学,1996(9):30-33.
[18]Charles W,Carnaje N P,Cordruwisch R.Methane conversion efficiency as a simple control parameter for an anaerobic digester at high loading rates[J].Water Science&Technology,2011,64(2):534-539.
[19]He R,Wei X M,Chen M,et al.Effects of concentrated leachate injection modes on stabilization of landfilled waste[J].Environmental Science&Pollution Research International,2015,23(4):1-9.
[20]Sun Y,Sun X,Zhao Y.Comparison of semi-aerobic and anaerobic degradation of refuse with recirculation after leachate treatment by aged refuse bioreactor[J].Waste Management,2011,31(6):1202-1209.
[21]Sun Y,Sun X,Zhao Y.Comparison of semi-aerobic and anaerobic degradation of refuse with recirculation after leachate treatment by aged refuse bioreactor[J].Waste Management,2011,31(6):1202-1209.
[22]Kayhanian M.Ammonia inhibition in high-solids biogasification:An overview and practical solutions[J].Environmental Technology,1999,20(4):355-365.
[23]Kjeldsen P,Barlaz M A,Rooker A P,et al.Present and Long-Term Composition of MSW Landfill Leachate:A Review[J].Critical Reviews in Environmental Science&Technology,2002,32(4):297-336.
[24]Menkveld H W H,Broeders E.Recovery of ammonium from digestate as fertilizer[J].Water Practice&Technology,2017,12(3):514-519.
[25]Sprott G D,Patel G B.Ammonia toxicity in pure cultures of methanogenic bacteria[J].Systematic&Applied Microbiology,1986,7(2):358-363.
[26]Desloover J,Woldeyohannis A A,Verstraete W,et al.Electrochemical resource recovery from digestate to prevent ammonia toxicity during anaerobic digestion[J].Environmental Science&Technology,2012,46(21):12209-12216.
[27]Wang Y,Zhang Y,Wang J,et al.Effects of volatile fatty acid concentrations on methane yield and methanogenic bacteria[J].Biomass&Bioenergy,2009,33(5):848-853.
[28]Yeole T Y,Gokhale S,Hajarnis S R,et al.Effect of brackish water on biogas production from cattle dung and methanogens[J].Bioresource Technology,1996,58(3):323-325.
[29]Kim B C,Jeon B S,Kim S I,et al.Caproiciproducens galactitolivorans gen.nov.sp.nov.,a bacterium capable of producing caproic acid from galactitol,isolated from a wastewater treatment plant[J].International Journal of Systematic&Evolutionary Microbiology,2015,65(12):4902.
[30]Liu M K,Tang Y M,Guo X J,et al.Deep sequencing reveals high bacterial diversity and phylogenetic novelty in pit mud from Luzhou Laojiao cellars for Chinese strong-flavor Baijiu[J].Food Research International,2017,102:68-72.
[31]Mali Sandip T,Khare Kanchan C,Biradar Ashok H.Enhancement of methane production and bio-stabilisation of municipal solid waste in anaerobic bioreactor landfill[J].Bioresource Technology,2012,110:10-17.