Biogas Emissions Research Articles

Comparison between Biogas Concentrations Emitted by Two Open Landfills: Truitier (Haiti) and Gabarre (Guadeloupe)

Household and related wastes management become a real problem in modern society. The increasing amount of waste led to use more and more waste incinerators and landfills. In underdeveloped countries, most of the collected garbage is left in uncontrolled open landfills. The open landfill, with flying plastic and biogas emission, creates nuisance for the neighboring environment and population. The main gases produced by waste decomposition are VOCS (Volatile Organic Compounds) and hydrogen sulphide (H2S). In our study located in Haiti and Guadeloupe, we used hydrogen sulphide as a tracer gas to determine the impact on the environment and human health. Our measurement campaign was both held in Haiti and Guadeloupe. In the controlled garbage dump of Gabarre (Guadeloupe), a portion is completely replanted, and the other hand receives all types of waste. The biogas from the garbage dump Gabarre is channeled into pipes, which will be burned by flare. The uncontrolled garbage dump of Truitier (Haiti) is only controlled by the scavengers. They put the waste in fire, and all the sites are under a smoke plume. To evaluate the emission of gas, we have to identify the center of the landfill and the measurement point rentals. The points have been selected downwind of the landfill taking in account the average local wind direction, in order to observe the gas evolution of the garbage dump. We observed from the performed concentration of H2S, a same belt behavior for both sites with low concentration soon in the morning, a maximum raised around midday, followed by a decrease during the afternoon. This observed behavior suggest year influence of sun energy on the emission rate. With the maximum concentration, the intensity and the direction of the wind, we calculated the emissivity reported to a central point. We compared their emissivity taking in account the daily amount of waste, the total surface of the landfill and the waste composition ratio. With these first results, we evaluated and compared the concentration of the biogas and their impact on neighboring populations in Port au Prince (Haiti) and Guadeloupe.

Reducing biogas emissions from village-scale plant with optimal floating-drum biogas storage tank and operation parameters

In this study, an approach to optimize the components and operation of biogas plant systems, which temporarily stores biogas in floating-drum biogas storage tank (BS) and feeds in a semi-continuous manner, was developed. First, the parameters of biogas production and consumption were characterized into mathematical models, and estimated with a 1-year operating data set of a village-scale biogas plant (fermentation volume, 80 m3). Then, the established models, which included biogas production and consumption rates, were used to determine the optimal BS volume and operation parameters for improving biogas plant performance. In contrast to the biogas usage level achieved with the established BS (76.4%), that obtained with an optimal system could reach up to 85.7% and the feeding frequency for a 1-year operation could be decreased 6.5 times. Our proposed approach exhibited a number of attractive features, including accurate determination of parameters, reduced biogas emission, and cost efficiency, which may not only enhance biogas benefits, but also increase economic and environmental feedback on village-scale biogas plant operation.

Research of Biogas Purification Using Microalgae Monoraphidium Griffithii Suspension

Using biogas instead of fossil fuels decreases pollutants such as solid particles, sulphur dioxide, nitrogen oxides concentrations in the environment. Green energy and development of relevant infrastructure improves air quality considerably. Chemical, physical, biological methods are used for biogas purification. The main difficulties using biological methods are selection of suitable microorganisms’ suspensions and making optimal conditions in photobioreactor. Different origin and structure microalgae suspensions are used applying biological treatment methods. Monoraphidium griffithi, which is widespread in fresh water, has relatively high potential. Microalgae’ cultures absorb the main components of biogas – carbon dioxide (CO2) and hydrogen sulphide (H2S). Absorbtion processes are based on photosynthesis. Microalgae absorb specific components of biogas when there are suitable light source and nutrient solvent. The main purposes of the research are to asses emission of biogas using different substrates (chicken manure and wastewater sludge). Also, it was measured main physical and chemical characteristics of both substrates: acidicy, temperature, redox potential, conductivity, biohemical oxygen demand. According results of the research, emission from wastewater sludge is greater than from chicken manure so sludge was chosen in teh next stage of the research. The next stage – asssessment of purification efficienty using Monoraphidium grifftihii suspension. Raw biogas was supplied to photobioreacor (with microalgae suspension). Alterations of methane, carbon dioxide, oxygen, hydrogen sulphide concentrations were measured precisely. According to results concentration of methane in the beginning of the researc was 62%, after 35 days – 69%. Meanwhile carbon dioxide – 37% and 31% by analogy. Experimental research alows to assess Monoraphidium griffithi absorption capacity of ballast components. Results were compared to different scientists’ results which were present in scientific journals and publications. Comparative analysis alows to assess practical possibilities to use Monoraphidium griffithi as biological treatment of raw biogas.

Modern Landfills as Potential Feed Back Processes to Counteract Global Warming

Provided that produced biogas is effectively collected, landfills are important sinks for organic carbon compensating for emissions of CO2 from burning of fossil fuels. Sequestrating of long-lived organic carbon in the landfill itself is the most pronounced factor, but also other processes during landfill management will increase the capture and binding of CO2.. Compost produced in connection to the landfills and applied as soil improvement, is another important sink for organic carbon.The landfills in the World have been estimated to accumulate around 100 x 106 metric tons of C. Normally about 25-40 percent of the total carbon content in the waste can be converted into biogas in traditional landfills. During landfilling most of the organic carbon in fossil derived products, like plastics, synthetic rubber, textiles and other synthetic materials, As these products take part in the methane gas production, the landfill gas (biogas) can be regarded as a true biofuel. In contrast to incineration, high moisture content in the waste will not decrease the yield of energy per ton of waste. In a reactor landfill treating approximately 100 000 tons of waste per year, a longlived organic fraction corresponding to about 45 000 metric tons of carbon dioxide is longterm accumulated each year. This compensates for the annual carbon dioxide emissions from about 15 000 – 20 000 cars, provided that each one runs 15 000 km per year with fossil fuel. The technique for effective collection of landfill gas, and new techniques to upgrade and liquefy the biogas, have decreased the risk for emissions to the atmosphere. Modern bioreactor landfills have been estimated to have less than 10% diffuse biogas emissions to the atmosphere. Also in Sweden (Helsingborg), plants are built to convert landfill gas to upgraded, liquefied motor fuel. This will lead to strongly reduced diffuse emissions of landfill gas to the atmosphere. The utilization of leachates as forest fertilizer results in an improved biomass production and increased accumulation of soil organic matter. Increased tree and field layer productivity also means that the potential for water evaporation (eg. evapotranspiration) increase, reducing the costs for waste-water treatment or the risk for diffuse ground water pollution. Also in the mineral soil, increased long-lived fractions of humus normally are found. This should be added to the carbon accumulating effect of the landfill itself, where long-lived organic matter, mainly derived from lignin and from fossil fractions as plastics and synthetic textiles is long-term accumulated. In this respect the landfill system has similar effects compared to natural peatlands and lake and sea sediments, Ifproduced biogas is collected effectively, the landfill thus can be an important factor to counteract the “green-house effect” and climate change.

Examining the Effects of Covered Landfills on Gas Emissions in Parc Baldwin, Montreal

Background: Within recent years, parks built on top of former landfills have come under scrutiny for their effectiveness at mitigating the effects of the landfill underneath. The purpose of this study is to identify the biogas emissions of converted landfills nearly a century after landfill closure. Methods: Soil and air emissions for methane and carbon dioxide were collected at 112 sites within the North and South portions of Parc Baldwin in Montreal, Quebec, as well as the presumed boundaries of the former landfill. Results: Overall, it was found that South Baldwin and the immediate area (previously a landfill) had a higher mean average methane concentration, as well as a greater number of sites with methane present than North Baldwin. Particular raised areas in South Baldwin showed anomalously high carbon dioxide concentrations. There was a large degree of heterogeneity between emissions at different sites. Limitations: The Eagle 2 machine is limited to measuring only up to 5,000 ppm or 0.5% volume. Another difficulty with the variation in collection of the data is the differences in collection dates. Conclusions: Ultimately, while South Baldwin did have higher CO2 and methane emissions compared to its counterpart, it is inconclusive whether or not this phenomenon is related to the landfill or other factors. Gas concentrations were significantly below the lower explosive limit in both parks.

Technical and economic evaluation of biogas capture and treatment for the Piedras Blancas landfill in Córdoba, Argentina

ABSTRACTLandfill gas (LFG) management is one of the most important tasks for landfill operation and closure because of its impact in potential global warming. The aim of this work is to present a case history evaluating an LFG capture and treatment system for the present landfill facility in Córdoba, Argentina. The results may be relevant for many developing countries around the world where landfill gas is not being properly managed. The LFG generation is evaluated by modeling gas production applying the zero-order model, Landfill Gas Emissions Model (LandGEM; U.S. Environmental Protection Agency [EPA]), Scholl Canyon model, and triangular model. Variability in waste properties, weather, and landfill management conditions are analyzed in order to evaluate the feasibility of implementing different treatment systems. The results show the advantages of capturing and treating LFG in order to reduce the emissions of gases responsible for global warming and to determine the revenue rate needed for the project’s financial requirements. This particular project reduces by half the emission of equivalent tons of carbon dioxide (CO2) compared with the situation where there is no gas treatment. In addition, the study highlights the need for a change in the electricity prices if it is to be economically feasible to implement the project in the current Argentinean electrical market.Implications: Methane has 21 times more greenhouse gas potential than carbon dioxide. Because of that, it is of great importance to adequately manage biogas emissions from landfills. In addition, it is environmentally convenient to use this product as an alternative energy source, since it prevents methane emissions while preventing fossil fuel consumption, minimizing carbon dioxide emissions. Performed analysis indicated that biogas capturing and energy generation implies 3 times less equivalent carbon dioxide emissions; however, a change in the Argentinean electrical market fees are required to guarantee the financial feasibility of the project.

Direct landfill disposal versus Mechanical Biological Treatment (MBT)

Abstract After the implementation of a new waste management system, in which recycling is the most dominating process, landfill disposal still appears to be the most popular method of waste management in Poland, in which waste undergoes gradual decomposition and the influence of climate conditions, for example, air and atmospheric fallout, leads to the production of leachate and biogas emissions, which contribute to continual threats to the natural environment and humans. The above-mentioned threats can be limited by applying suitable techniques of waste treatment before its disposal. A technology that is oriented to these aims is a mechanical biological treatment (MBT) before disposal. The above-mentioned technology results is waste stabilisation and reduction of pollutant emissions. Additionally, it allows to increase the recovery of materials for recycling and to reduce the mass of waste. Finally, it is environmentally friendly.

Sulfur-enriched biochar as a potential soil amendment and fertiliser

Hydrogen sulfide (H2S) is a highly toxic and corrosive contaminant gas co-generated during anaerobic digestion. Studies have shown that biochars have the potential to adsorb H2S and to promote its oxidisation. To date, no studies have investigated the bioavailabilty to plants of the sulfur (S) contained in biochar when used as an S fertiliser. Biochar was packed into the biogas emissions stream to adsorb the H2S being generated. The resulting sulfur-enriched biochar (SulfaChar) and synthetic S fertiliser (control treatment) were amended to potting soils and the growth response of corn (Zea mays L.) and soybeans [Glycine max (L.) Merr.] and nutrient uptake were measured after a 90-day greenhouse study. SulfaChar contained 36.5% S (S element and SO42–), confirming it adsorbed significant amounts of H2S. Compared with the control treatment, SulfaChar amendment significantly increased corn plant biomass, ranging from 31% to 49% but only a slight increase in soybean biomass (4 to 14%). SulfaChar also increased corn plant uptake of S and other macro- (N, P, K, Ca, and Mg) and micro-nutrients (Zn, Mn and B). Our results show that SulfaChar was a source of plant available S, suggesting that SulfaChar is either a supplier of these nutrients or that it promoted their uptake.

ENERGY GENERATION FROM MUNICIPAL SOLID WASTE AND THE CURRENT SCENARIO OF BIOGAS RECOVERY IN BRAZIL

The landfill is a method of treatment and final disposal of municipal solid waste (MSW) widely employed all over the world, mainly in developing countries. The biogas released from landfills raises environmental concerns, as it contributes to the greenhouse effect, due to its high content of methane and carbon dioxide, and in relation to the potential damage to health caused to the surrounding populations of these areas. However, biogas has a great energy potential, representing economic and environmental advantages, making the waste disposal in landfills more sustainable in relation to these economic and environmental aspects. In Brazil, few landfills are technically prepared in recovering energy from biogas, which may be encouraged by the new Solid Waste National Policy, which aims to fit the landfills to the technical criteria of engineering, as well as to provide appropriate instructions on the waste management throughout its life cycle. The present review deals with the process of biogas generation based on municipal solid waste and some techniques that provide quantitative data on the biogas emission, and also the current scenario in Brazil related to the energy recovery from such source of bioenergy and its future potentialities.

Potentiality of Biogas as Renewable Energy Technology and its role for the Conservation of Environment

The study shows the status of biogas as a Renewable Energy Technology (RET) and its role in the conservation of environment by reducing the consumption of fuelwood and Greenhouse Gases (GHGs) emission. 95 household survey, 10 key informant interviews, 3 focus group discussion and direct observatory technique were used for primary data collection. Fuelwood was found to be dominant energy resource which comprises 93.73% of total energy and rest 6.27% of energy was supplied by other sources of energy. The fuelwood consumption was 71.29 GJ per year per household which emits 646.1 tCO2e. The study shows that the annual GHGs reduction was found 7.62 tCO2e per biogas plant. On the basis of population of the agriculture based livestock of the study area, there was the possibility of 84 biogas plants of size 6 m3 which can reduce the total 638.82 tCO2e of GHGs emission per year. The study showed that the use of biogas technology can save 46.67% of fuelwood which can conserve 217.32 tons of fuelwood per year per household. The simple payback period in term of fuelwood saved for the construction of 6 m3 biogas plant was found to be only 4.08 years. Thus, the reduction or substitution of fuelwood as a primary energy resource, reduction of the GHGs emission and high potentiality of biogas in the area with adequate number of agriculture based livestock clearly indicates that biogas is as a suitable RET in reducing GHGs emission and helps in mitigating climate change.

Analysis of operational methane emissions from pressure relief valves from biogas storages of biogas plants

The study presents the development of a method for the long term monitoring of methane emissions from pressure relief valves (PRV1PRV: pressure relief valve.1) of biogas storages, which has been verified during test series at two PRVs of two agricultural biogas plants located in Germany. The determined methane emission factors are 0.12gCH4kWhel−1 (0.06% CH4-loss, within 106days, 161 triggering events, winter season) from biogas plant A and 6.80/7.44gCH4kWhel−1 (3.60/3.88% CH4-loss, within 66days, 452 triggering events, summer season) from biogas plant B. Besides the operational state of the biogas plant (e.g. malfunction of the combined heat and power unit), the mode of operation of the biogas flare, which can be manually or automatically operated as well as the atmospheric conditions (e.g. drop of the atmospheric pressure) can also affect the biogas emission from PRVs.

Potential of Sverdlovsk Oblast and Yekaterinburg Environmental Sector

The article discusses the problems associated with introduction of new administrative approaches to solid waste management, as well as the choice of priority directions in the development of the regional waste treatment schemes, which may increase the efficiency of the environmental sector in the city (region) and improve the ecology in general. The authors analyze the factors, which may lead to environmental deterioration and endanger the ecological safety of Yekaterinburg and Sverdlovsk Oblast. They also highlight the priority challenges, one of which is utilization of the biogas produced in the municipal solid waste landfills. In the context of the existing administrative districts, the paper analyzes the results of calculations of biogas production and emissions from the waste incineration plants in Yekaterinburg and Sverdlovsk Oblast. The authors offer an algorithm, which helps to evaluate the reduction of methane emissions to the atmosphere after introduction of a biogas combustion technology. The article also discusses the author’s recommendations on how to justify the directions in the development of the regional waste management schemes, which will increase the efficiency of the companies operating in the field of waste management.

INVESTIGATION OF THE PROCESSES OF BIODEGRADA-TION OF SORTED MUNICIPAL SOLID WASTE IN LAND-FILL REACTOR

The article describes methods to intensify the processes of biodegradation. The results of the investigations of waste biodegradation process modeling of waste and the intensification of these processes are given. Generalized mathematical model of emission of biogas at the landfill is developed and methods of process intensification in the body of the landfill are proved. As a result of research, microbiological and biochemical processes in the body of the landfill are analyzed, the main factors affecting the intensity of the processes are revealed and their impact is analyzed. It was concluded that the landfill is a biochemical reactor, where interrelated heat and mass transfer processes occur in the dense bed through which the gas is filtered and internal sources of heat. It was developed a complete mathematical model allowing estimating based on the equations of material and heat balances, the rate of biogas reactor. A model and calculation method for the analysis of heat and mass transfer processes in a dense bed with internal heat sources and to calculate the emission of biogas at design and operation of the landfill-reactor were given. Possible ways of intensifying the process of biodegradation in the reactor were revealed on the basis of analysis of the equations of the mathematical model describing the process in the reactor and the theory of microbiological processes of this class.

The influence of lower temperature, influent fluctuations and long retention time on the performance of an upflow mode laboratory-scale septic tank

The influence of temperature in a range of 15–5°C, fluctuations in soluble chemical oxygen demand (sCOD) and suspended solids (SS) of the influent and also long hydraulic retention times (HRT) of 36 or 50 d on the performance of a laboratory septic tank were studied. A laboratory-scale septic tank with a volume of 20 L, started up at 15°C was fed with domestic wastewater from two settlements with sCOD up to 450 and up to 2,000 mg/L, respectively. The efficiency of the septic tank was assessed based on pollutant removal and biogas production. A stepwise decrease in temperature by 5°C in the range of 15–5°C halved the daily emission of biogas. Removal efficiencies for sCOD and SS were in the range of 74–86 and 86–88%, respectively. An increase in sCOD of influent from 450 to 4,000 mg/L resulted in a decreased performance of the septic tank (to ~25% less). The highest biogas emission was observed at 10°C and at retention time (36 d), owing to increased consumption of CO2 and CH4 by autotrophic microorganisms over the longer retention time (50 d). At the 15°C, biogas emission was lower than in case of lower temperatures applied. In the range of 15–5°C, operational temperature did not correlate significantly (p > 0.05) with the removal efficiency of sCOD or SS, assuming as a consequence of the long HRT.

Landfill aeration for emission control before and during landfill mining

The landfill of Modena, in northern Italy, is now crossed by the new high velocity railway line connecting Milan and Bologna. Waste was completely removed from a part of the landfill and a trench for the train line was built. With the aim of facilitating excavation and further disposal of the material extracted, suitable measures were defined. In order to prevent undesired emissions into the excavation area, the aerobic in situ stabilisation by means of the Airflow technology took place before and during the Landfill Mining. Specific project features involved the pneumatic leachate extraction from the aeration wells (to keep the leachate table low inside the landfill and increase the volume of waste available for air migration) and the controlled moisture addition into a limited zone, for a preliminary evaluation of the effects on process enhancement. Waste and leachate were periodically sampled in the landfill during the aeration before the excavation, for quality assessment over time; the evolution of biogas composition in the landfill body and in the extraction system for different plant set-ups during the project was monitored, with specific focus on uncontrolled migration into the excavation area.Waste biological stability significantly increased during the aeration (waste respiration index dropped to 33% of the initial value after six months). Leachate head decreased from 4 to 1.5m; leachate recirculation tests proved the beneficial effects of moisture addition on temperature control, without hampering waste aerobization. Proper management of the aeration plant enabled the minimization of uncontrolled biogas emissions into the excavation area.

Production of renewable energy on closed landfills to compensate for biogas emissions: A case study of the Valdina landfill (Messina, Italy)

<div> <p>The contribution of integrated municipal solid waste (MSW) management systems to greenhouse gas emissions is not negligible, even though it is moderate compared with other anthropogenic activities. The main emission from landfills that accept biodegradable MSW is methane that escapes from the biogas collection system. Such emissions are partially compensated if the collected biogas is exploited for energy production. Further compensation measures would also increase the overall sustainability of the landfill site. This study analyses the possibility of exploiting closed landfills to produce energy based on the case study of the Valdina landfill (Messina, Italy). Two possible scenarios are presented: the installation of a photovoltaic system and the cultivation of giant reed (<em>Arundo donax L.</em>) to be used for energy production through combustion. The results of a preliminary experimental activity are presented for the second scenario. The findings demonstrate the possibility of using the leachate produced in the landfill for irrigation purposes. For each scenario, the costs, potential energy production rate, avoided emissions and issues related to the integration of energy production with the landfill aftercare are evaluated. The presented results suggest that the cultivation of giant reed is the best option, especially during the early post-closure period, in terms of investment (18,000 € against 8,300,000 €), high production yield in the Mediterranean climate, simplicity of cultivation and integration with ordinary post-closure landfill management, limited cost of the energy produced (0.1€ kWh<sup>-1 </sup>against 0.27€ kWh<sup>-1</sup>). On the other hand avoided emissions are higher for the photovoltaic plant (27804  against 778  on an horizon of 20 years).</p> </div> <p> </p>

Ecological Threats Caused by Improper Disposal and Incineration of Municipal Solid Waste

The paper discusses a critical situation regarding municipal solid waste (MSW) in Donetsk city (Ukraine) as a suitable example. Special attention is given to such problems as bio-degradation and self-ignition of MSW dumps as well as the hazard of dioxins that might be present in the emitted gases. The paper describes the materials as well as techniques used for experiments and calculations of results. The paper offers theoretical calculations of biogas emissions from MSW landfill bodies as well as the results of experimental measurements performed within laboratory conditions of a “MSW micro-landfill”. Dynamics of development of microorganism colonies within the body of MSW has been studied experimentally and a mathematical model of these processes was developed. There was calculated a volume of leachate (“MSW-sewage”) produced at MSW landfills as well as migration of toxic waste from the leachate to underground water and soil surrounding MSW landfills of Donetsk. MSW self-ignition processes taking place within waste layers and diffusion of toxic fire-hazardous gases have been studied both theoretically and experimentally. There have been developed and proposed techniques of forecasting and prevention of MSW self-ignition within MSW layers. Processes of MSW incineration together with resinous industrial waste have been studied within the framework of experiments, namely: there were measured emissions of toxic combustion gases and heavy metals as well as “distribution” of the latter in combustion gases and ash

Математическое моделирование процессов анаэробного сбраживания органического субстрата. обзор

An analysis of existing models of anaerobic fermentation of organic matter with biogas emission is performed. The most used in the literature models describing the kinetics of methane fermentation, as well as the kinetic parameters of the process are presented. The proposed models describe the growth and development of the microbial population, the degradation of substrate components and formation of reaction products in the anaerobic microbial bioreactor.

Power generation with biogas from municipal solid waste: Prediction of gas generation with in situ parameters

Abstract Estimations of biogas emissions in final disposal sites have been studied by several researchers, primarily for their potential as a renewable source of energy and greenhouse gas emissions mitigation. Different models have been developed to predict the generation of biogas; the first-order model is widely used. Most of these models are based on two parameters, the methane generation rate (k) and methane generation potential (L0). These parameters cannot be generalized for biogas estimation in any site, and must be modified according to in situ characteristics. The objectives of this research are (a) modify the constants of k and L0 with in situ data, and (b) estimate the biogas generation in a sanitary landfill of a Mexican city using the modified constants. The following data were used in modifying the model constants biogas: (a) waste characterization studies, (b) biogas extraction tests, (c) observations of characteristics and sanitary landfill operation, (d) interviews with the managers of the sanitary landfill, and (e) several parameters of the Intergovernmental Panel on Climate Change (IPCC) model. Biogas estimation using the modified constants was performed in the version 2.0 Mexico Landfill Gas Model proposed by Stearns, Conrad and Schmidt Consulting Engineers, Inc. (SCS Engineers). The results show that approximately 70% of the waste generated is organic, which influences the value of the parameters used in calculating the k and L0. With in situ characteristics, values of k=0.0482 yr−1 and L0=94,457 m3/t were obtained. It is projected that the electric power generation could reach a maximum capacity of 2.4 MW in 2019. This energy could increase the installed capacity in the Ensenada by approximately 4.36% and supply approximately 66% of the electric energy required for lighting, which amounts to savings of US$2.62 million and an environmental benefit of approximately 1.17 Mt CO2e from 2009 to 2025.

Kinetics of simultaneous methane and toluene biofiltration in an inert packed bed

AbstractBACKGROUNDBiofiltration of methane is of particular interest to contribute to limiting the greenhouse gas effect of biogas emissions from landfills. The complexity of the biogas mixture from landfills has underlined the importance of the presence of non‐methane organic compounds. The aim of this study was to determine the effect of toluene on the microkinetic and macrokinetic parameters of methane biodegradation using an inorganic filter bed.RESULTSTwo concentrations of toluene were tested, 0.7 and 3.4 gC m−3, and compared with the case of methane biofiltration alone. The specific growth rates of methane decreased from 0.793 to 0.574 to 0.278 d−1 when the toluene concentration was increased from 0 to 0.7 to 3.4 gC m−3, respectively. The maximum elimination capacity of methane decreased from 39.4 to 5.6 gC m−3 h−1 when toluene concentration was increased from 0 to 3.4 gC m−3. The half‐saturation constants decreased from 4.6 to 1.6 gC m−3 and from 4.6 to 0.7 gC m−3, respectively.CONCLUSIONSResults show that an inhibition occurred on methane biodegradation when toluene was introduced into the biofilter. © 2013 Society of Chemical Industry