Electronic waste (e-waste) has become one of the fastest-growing waste streams in the world. However, only 17.4% of it can be collected and recycled in 2019. This study aims to formulate strategies to improve the supply chain of e-waste management in Indonesia. Methods used to develop strategies in this study are the Decision-Making Trial and Evaluation Laboratory (DEMATEL), the Analytical Network Process (ANP), Strength–Weaknesses–Opportunities–Threats (SWOT), and the Quantitative Strategic Planning Matrix (QSPM). The results show that infrastructure criteria have the largest weight, that is 0.267, followed by a social environment with 0.261, regulation with 0.244, stakeholder with 0.122, and economy with 0.054. The top priority of the selected strategies is to improve public education (ST1) and provide socialization of regulations and sanctions to the public (ST2).

The number of vehicles in Indonesia increases significantly from year to year. This has an impact on various aspects such as traffic jams, air pollution, traffic accidents etc. The purpose of this study is to obtain the best model for forecast the number of cars and the number of motorcycles in the next 11 years. For the purpose, ARIMA method was used. Using the historical data of the number of cars and the number of motorcycles from 2001 to 2019, the best model for forecasting the number of cars and the number of motorcycles is ARIMA (1,1,0) and ARIMA (2,1,2), respectively. The models have MAPE of 7.01% and 7.24% for cars and motorcycles, respectively.

Background: The growing issues about waste management and climate change compel the exploration and implementation of sustainable energy solutions derived from waste. In this context, Refuse-Derived Fuel (RDF), a processed solid fuel generated from municipal solid waste (MSW), presents itself as a promising strategy. By offering an alternative to conventional fossil fuels, RDF can mitigate the environmental impact of MSW and potentially reduce greenhouse gas emissions. RDF can provide cleaner energy for a more sustainable future. Objective: This study aims to evaluate the RDF site's economic condition, revenue generation, costs, and the net benefit from RDF production in RDF Plant-based landfills in Indonesia. Method: In addition, cost–benefit analysis (CBA) was carried out to study the economic factors. Result: According to cost-benefit analysis, benefits are higher than production costs. The net benefit gained in this study is IDR 33.035.853.659, with each ton of RDF offering IDR 1.242.977 in benefits. The study revealed that revenue per ton RDF is about IDR 414.000, with a production cost RDF of 342.388 per ton. Conclusion: The study concludes that utilizing all generated waste into RDF presents a financially beneficial strategy for municipalities and consumers (cement kilns). Findings indicate the potential for RDF implementation to yield cost savings and land savings.

The increased population and economic of the community indirectly affect the amount of household waste produced by the community. Unfortunately, this is not accompanied by good waste management from the community level. Management of household waste at the community level can be done by sorting waste. The habit of people to dispose of garbage without sorting can be a problem in implementing 3R activities (Recycling, Reducing, and Reusing). The purpose of this study is to find out what factors influence the community in sorting household waste. This research is based on the Theory of Planned Behavior (TPB) which considers several factors such as attitudes, subjective norms, and behavioral controls to influence someone to make intentions in behavior and expand the TPB conceptual model to overcome gaps. The results of this study came from a survey with 301 respondents in two locations namely DKI Jakarta and Depok. The results of this study indicate that attitudinal factors have the most significant influence on the intention and behavior of sorting garbage. While other factors such as demographics, subjective norms and perceptions of behavioral control do not have a significant effect.

Indonesia is one of the biggest plastic waste production in the world. The government targets to reach 20% for recycling plastic waste in 2019. One alternative to manage plastic waste is using pyrolysis to produce fuel. Pyrolysis is used to degrade the plastic long chain of polymer molecules into smaller molecules. All type of plastic except polyvinyl chloride (PVC) were used in this study to produce fuel. For the purpose, experiment factorial design was used for the optimisation plastic type, residence time, and temperature to maximise the yield of liquid products of the pyrolysis process. In this study 2k factorial design was used for each factor. The result shows that the pyrolysis process used is able to produce diesel like fuel in low temperature.