Municipal solid waste (MSW) management is one of the utmost challenges for Cambodia’s city and district centers. The unsound management of MSW has detrimentally affected the environment and human health. In the present study, an attempt has been made to provide a comprehensive insight into the generation and characteristics, policies and legislation frameworks, management arrangement, collection, treatment, and disposal of MSW. The experience of developed and developing countries and the challenges and priorities of MSW management in Cambodia are also highlighted. In Cambodia, about 4.78 million tons of MSW were generated in 2020, with a 0.78 kg/capita/day generation rate. Only 86% of cities and districts have access to MSW collection services. The current practice of MSW management is reliance on landfill (44%). There are 164 landfills operating countrywide, receiving about 5749 tons of MSW per day. Recycling, incineration, and composting share 4%, 4%, and 2% of MSW generation, respectively. In 2021, the total revenue that was recovered from recyclables was USD 56M. The study concludes several major challenges and proposes valuable suggestions, which may be beneficial for the improvement of the current system to support the sustainable management of MSW in Cambodia.

This study assessed the energy potential, economic feasibility, and environmental performance of landfill gas (LFG) recovery, incineration, and anaerobic digestion (AD) technologies for Phnom Penh municipality in Cambodia, from 2023 to 2042. The economic analysis utilized the levelized cost of electricity (LCOE), payback period (PBP), and net present value (NPV) to evaluate the feasibility of each technology. Additionally, environmental performance was assessed following the IPCC 2006 guidelines. The results indicate that incineration produced the highest energy output, ranging from 793.13 to 1625.81 GWh/year, while the LFG and AD technologies yielded equivalent amounts of 115.44–271.81 GWh/year and 162.59–333.29 GWh/year, respectively. The economic analysis revealed an average LCOE of 0.070 USD/kWh for LFG, 0.053 USD/kWh for incineration, and 0.093 USD/kWh for AD. Incineration and LFG recovery were found to be economically feasible, with positive NPVs and a potential for profit within 8.36 years for incineration and 7.13 years for LFG. In contrast, AD technology had a negative NPV and required over 20 years to generate a return on investment. However, AD was the most promising technology regarding environmental performance, saving approximately 133,784 tCO₂-eq/year. This study provides valuable technical information for policymakers, development partners, and potential investors to use in order to optimize waste-to-energy investment in Cambodia.

This study assesses the biomethane (CH₄) generation and greenhouse gas (GHG) emissions resulting from municipal solid waste landfilling in Phnom Penh, Cambodia, with a focus on the impact of fugitive CH₄ emissions and operation processes in four landfilling scenarios: simple dumping (S1), improved management with leachate treatment (S2), engineered landfill with flaring (S3), and engineered landfill with energy recovery (S4). The study also considered the environmental benefits of carbon sequestration and landfill gas utilization. The LandGEM and IPCC FOD models were used to calculate CH₄ generation over the period of 2009–2022, and it was found that approximately 18 and 21 M kg/year of CH₄ were released, respectively. The energy potential from CH₄ recovery was 51–61 GWh/year. Overall, GHG emissions in S2 were the highest, amounting to 409–509 M kg CO₂-eq/year, while S1 had lower emissions at 397–496 M kg CO₂-eq/year. Flaring-captured CH₄ in S3 could reduce GHG emissions by at least 55%, and using captured CH₄ for electricity production in S4 could mitigate at least 83% of GHG emissions. Electricity recovery (S4) could avoid significant amounts of GHG emissions (−52 to −63 kg CO₂-eq/tMSW). The study suggests that landfill gas-to-energy could significantly reduce GHG emissions.

Municipal solid waste management in developing countries faces limitations, especially concerning technologies for treatment and disposal, which is crucial for achieving environmental and economic sustainability goals. This paper investigates municipal solid waste management in Laos, compared with the ASEAN-Japan regions, focusing on background information, waste characteristics, environmental impact, and treatment technologies for resource utilization. The findings indicate a continuous rise in municipal waste generation in Laos, particularly in the capital Vientiane, from 0.21 million tons in 2012 to 0.37 million tons in 2021. Treatment methods include unsanitary landfilling, basic recycling, and open dumping, as well as burning or discharge into rivers, posing potential risks to the environment and human health. Japan and Singapore have shown decreasing trends, with Japan reducing from 45.23 million tons in 2012 to 40.95 million tons in 2021 and Singapore from 7.27 million tons in 2021 to 6.94 million tons in 2021. Laos encounters challenges in managing municipal waste, especially in waste recovery and waste-to-energy practices, crucial elements of integrated solid waste management aimed at promoting environmental and economic sustainability. Enhancing waste management in Laos involves developing a waste management act with segregation, recycling, and extended producer responsibility policies. Implementing mechanical biological treatment facilities, waste-to-energy plants, and upgraded landfills is crucial. Capacity building and public awareness campaigns on waste management will improve sustainability, reduce environmental impacts, and advance sustainable development goals for sustainable cities and communities.

Temperature and precipitation have been known as the key determinant factors to affect rice production in climate change. In this study, the relationship between climate variables and rice yields during 1993–2012 in Cambodia was analyzed and evaluated. The Ordinary Least Squares analysis was applied to examine the relationship of three climate variables (TCV) including maximum temperature, minimum temperature and rainfall against seasonal rice yields. By this period, a remarkable increasing trend of annual temperature was observed whilst rainfall was not significantly changed. The TCV explains approximately 63% and 56% of the variability of rice yields in wet and dry seasons, respectively. It is found that in Cambodia, non-climate factors such as fertilizers, water, cultivars, and soil fertility cause 40% variation to rice yields, whereas the remaining 60% can be influenced by climate variability. The levels of temperature difference (LTD) between maximum and minimum temperatures of the wet season (WS) and dry season (DS) were 7.0 and 8.6 ^oC, respectively. The lower value of LTD may cause the reduction of rice in WS (2.2 tons/ha) as compared to that of DS (3.0 tons/ha). Rice yield has increased 50.5% and 33.8% in DS and WS, respectively, may due to the improvement of rice cultivation practices in Cambodia such as the better use of fertilizers, pest and weed control, and irrigation, and more effective rice cultivated protocol, as the increased trend of temperature may detrimentally affect rice yield. The breeding of heat and drought tolerance rice varieties and development of irrigation system are effective to reduce the negative influence from climate change to rice production in Cambodia.