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Background and Objective: The initial step in managing methane emissions is quantification. This study aims to comprehensively investigate the methods for estimating and measuring methane gas emissions in municipal solid waste landfills. Materials and Methods: This systematic review includes studies published in English and Farsi between January 2005 and May 2023. English-language articles were included from PubMed, Web of Science, and Scopus databases, while Persian-language articles were included from SID, Majiran and Google Scholar. Results: After evaluating the studies, 90 studies providing information on methods for measuring and estimating methane gas emissions in urban landfills were selected. The results showed that emission estimates based on widely used models like LandGEM and IPCC, despite being lower in cost and providing faster results, are often associated with relatively high uncertainty. Therefore, quantitative and qualitative methods of direct measurement are preferred for accurately determining methane emissions from landfills. The most commonly used methods for measuring greenhouse gases, especially methane from landfills, include direct reading equipment and closed flux determination chambers. Conclusion: Estimating greenhouse gas emissions from primary sources allows responsible authorities to understand the current status of methane emissions and to formulate reduction strategies. The findings of estimated methane emissions from landfills can differ significantly from the actual measurements in some situations. Therefore, while these estimation methods are useful, fast and cost-effective tools, their inherent uncertainties should be considered when using them. [ABSTRACT FROM AUTHOR]

Background and Objective: Various models have been developed to predict methane generation and emissions from landfills. Due to their simplicity, the minimum number of required data, and the accuracy of the outputs, First-order decay are the most common models to predict methane generation in landfill,. Three important parameters in modeling landfill gas generation using a first-order model are the total weight of waste buried in the landfill, the methane generation potential, and the methane generation rate constant. The purpose of this research was to accurately estimate the parameters of the first-order model and to optimize it for estimating methane generation in the landfill and also to develop the ILGAM software. Materials and Methods: ILGAM model consists of two submodels: 1) the gas generation sub-model and 2) the methane oxidation sub-model. The methane oxidation sub-model is based on the MOT model. The gas generation sub-model is based on a first-order equation with an emphasis on the contribution of the aerobic process in the estimation of the ultimate methane potential of waste. The parameters of the equation were modeled using the latest available results in the literature. To evaluate the model, the actual methane emission and methane oxidation were measured in the Karaj landfill. The results of the model, along with a few common models, were compared with actual data obtained from the Karaj landfill. Results: The ILGAM model predicted the gas emission from the Karaj landfill with an error of 5.8%. In contrast, LandGem, IPCC and CLEEN models predicted the methane gas emission from the Karaj landfill with an error of 74.4%, 40.2%, and 27.1%, respectively. Conclusion: When compared to other models, the ILGAM model estimated the closest values to actual measurements for methane emission and methane oxidation in the Karaj landfill. Owing to its user-friend Graphical User Interface (GUI), the model can be easily executed in a wide range of landfills by entering a few easy-to-measure data in the field.

Background and Objective: Various models have been developed to predict methane generation and emissions from landfills. Due to their simplicity, the minimum number of required data, and the accuracy of the outputs, First-order decay are the most common models to predict methane generation in landfill,. Three important parameters in modeling landfill gas generation using a first-order model are the total weight of waste buried in the landfill, the methane generation potential, and the methane generation rate constant. The purpose of this research was to accurately estimate the parameters of the first-order model and to optimize it for estimating methane generation in the landfill and also to develop the ILGAM software. Materials and Methods: ILGAM model consists of two submodels: 1) the gas generation sub-model and 2) the methane oxidation sub-model. The methane oxidation sub-model is based on the MOT model. The gas generation sub-model is based on a first-order equation with an emphasis on the contribution of the aerobic process in the estimation of the ultimate methane potential of waste. The parameters of the equation were modeled using the latest available results in the literature. To evaluate the model, the actual methane emission and methane oxidation were measured in the Karaj landfill. The results of the model, along with a few common models, were compared with actual data obtained from the Karaj landfill. Results: The ILGAM model predicted the gas emission from the Karaj landfill with an error of 5.8%. In contrast, LandGem, IPCC and CLEEN models predicted the methane gas emission from the Karaj landfill with an error of 74.4%, 40.2%, and 27.1%, respectively. Conclusion: When compared to other models, the ILGAM model estimated the closest values to actual measurements for methane emission and methane oxidation in the Karaj landfill. Owing to its user-friend Graphical User Interface (GUI), the model can be easily executed in a wide range of landfills by entering a few easy-to-measure data in the field. [ABSTRACT FROM AUTHOR]