A B S T R A C TProducing biogas by anaerobic digestion (AD) is a promising process that can simultaneously provide renewable energy and dispose solid waste safely. However, this process could affect environment e.g. due to greenhouse gas emissions. By life cycle assessment (LCA), we assessed the environmental impact (EI) of an integrated fruit waste-based biogas system and its subsystems of Biogas Power Plant Gamping. Data were collected from an actual plant in Gamping, Sleman, Yogyakarta, Indonesia that adopted a wet AD process at mesophilic condition. The results showed that the global warming potential (GWP) emission of the system reached 81.95 kgCO2-eq/t, and the acidification potential (AP), eutrophication potential (EP), human toxicity potential (HTPinf) and fresh water ecotoxicity (FAETPinf) emissions were low. The EI was mainly generated by two subsystems, namely, the electricity generation and the digestate storage. A comparison analysis showed that the GWP become the main contributor of environmental loads produced by Biogas Plant Gamping, Suazhou Biogas Model, Opatokun Biogas Model, Opatokun Pyrolisis Model, dan Opatokun Integrated System Anaerobic Digestion and Pyrolisis. The GWP impact control and reduction could significantly reduce the EI of the system. It has been shown that improving the technology of the process, the electricity generation and the digestate storage will result in the reduction of EI of the biogas system.Keywords: environmental impact; fruit waste; life cycle assessment (LCA); renewable energyA B S T R A KProduksi listrik dari biogas dengan anaerobic digestion (AD) merupakan proses yang menjanjikan karena dapat menghasilkan energi listrik dan penanganan limbah padat dengan aman. Namun, proses ini mempengaruhi lingkungan akibat emisi gas rumah kaca. Penilaian dampak lingkungan (environmental impact atau EI) sistem biogas berbasis limbah terpadu dan subsistemnya terhadap Biogas Power Plant Gamping (BPG) dilakukan dengan metode life cycle assesement atau LCA. Data dikumpulkan dari plant yang sebenarnya di Gamping, Sleman, Yogyakarta, Indonesia yang mengadopsi proses AD basah pada kondisi mesofilik. Potensi pemanasan global (global warming potential atau GWP) dari sistem mencapai 81,95 kgCO2-eq/t, sedangkan potensi keasaman (acidification potential atau AP), potensi eutrofikasi (eutrophication potential atau EP), potensi toksisitas manusia (human toxicity potential atau HTPinf) dan ekotoksisitas air (fresh water ecotoxicity atau FAETPinf) potensi emisinya cukup rendah. Potensi EI terutama dihasilkan oleh dua subsistem, yaitu, pembangkit listrik dan penyimpanan digestate. Analisis perbandingan menunjukkan bahwa dampak GWP menjadi kontributor utama dari beban lingkungan yang dihasilkan oleh Biogas Plant Gamping, biogas model Suazhou, biogas model Opatokun, model pirolisis Opatokun, serta model integrasi AD dan pirolisis Opatokun. Pengendalian dan pengurangan dampak GWP secara signifikan dapat mengurangi EI dari sistem. Telah terbukti bahwa peningkatkan teknologi proses, pembangkit listrik dan penyimpanan digestate akan menghasilkan pengurangan EI dari sistem biogas.Kata kunci: dampak lingkungan; energi terbarukan; life cycle assessment (LCA); limbah buah

The production of biogas by anaerobic digestion (AD) from fruit waste and then converting biogas to electricity is an innovative approach in the development of renewable energy. To study the sustainability of the process, it important to analysis the environ-socio-economic benefits of the technology. In this study, the life cycle sustainability assessment (LCSA) were carried out in a fruit waste biogas plant system, which located in the Gemah Ripah Central Fruit Market in Indonesia. The AD system was designed for 4000 kg/day feed and supplies 148.5 kWh/day electricity. The results of assessment of environmental, economic and social aspects are 5.00 (very good), 3.00 (moderate), and 4.00 (good). This study indicates that biogas plant from fruit waste has a significant advantage for environment, economic, and society. Overall, the sustainability of BPG is in the category of very good (grade I) with a value 4.11 from maximum value of 5.

Gemah ripah biogas (GRB) plant is the first biogas project in Indonesia that utilizes a 100% fruit waste as a feedstock. Now, the biogas has been operating for almost 9 years. To get objective performance study in the biogas plant existing, it important to analyze biogas production, electricity generation and energy and environmental benefits of the GRB plant. This paper presents a comprehensive analysis of the typical demonstration model in utilization of fruit waste. Regarding the observation, technically GRB has operated in appropriate function. GRB was designed for 4 T/day feed and supplies 148.5 kWh/day electricity. The further analysis exhibited that GRB project is required to be optimized for maximum energy and environmental benefits because biogas plant feed only 0.35 T/day (8% of feed design) and supplies electricity only 0.45 % of its supplies. For biogas quality, data showed that the biogas plant produces methane and carbon dioxide with average content of 59% and 37% which is already within a good standard. GRB need some of recommendation for maximum operation which is discussed in this article. Nevertheless, operating as an example of a sustainable renewable energy model, GRB can decrease of waste discharge to the landfill and utilization of waste at the source. The operation model of GRB plays an important role in reducing greenhouse, mitigating pollution and generating renewable energy.

Biogas is produced from the anaerobic digestion of biodegradable organic matter. However, its application is limited because it contains impurities such as carbon dioxide (CO2) in high concentrations. Therefore, it is necessary to remove CO2 to improve the energy content of biogas. Porous adsorbents such as activated carbon have been widely used to remove CO2 from biogas. However, the performance of the split is limited, so the addition of active sites is required. In this research, chitosan impregnated porous carbon was used for biogas purification. Modification of porous carbon was made by impregnating chitosan on activated carbon with a ratio of chitosan to activated carbon of 0:1, 0.1:1, and 0.3:1. The success of the impregnation process of chitosan into activated carbon was analyzed from the results of characterization using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). Meanwhile, to determine the concentration of CO2 in biogas using Gas Chromatography (GC). The result showed that chitosan impregnated on activated carbon (0.1:1 w/w) can purify biogas up to 95 % compared to porous carbon.

Wastewater contains pollutants that can disturb the balance of the ecosystem in the form of health problems, water quality degradation and others. According to Said, (2008) the problem experienced in almost all cities in Indonesia is wastewater pollution. The purpose of this study is to determine the distribution of conditions and performance values, factors that influence the conditions and performance of Communal WWTPs in Sleman Regency Yogyakarta. The method used in this study is an interview with the help of guidelines to respondents who have been determined. The location of the sample collection was determined by the stratified random sampling method based on the District and Village for the decision of data collection at 30 Communal WWTPs of Sleman Regency. The results of the interview are processed by the Likert scoring method and then drawn with the Radar Chart. The factors that influence the conditions and performance of Communal WWTPs are then obtained from the ranking of the criteria for the conditions and performance of Communal WWTPs that have been calculated. The results showed that overall Communal WWTPs in Sleman Regency had conditions and performance with a value of 2.98 which was included in the interval of value 3 with a fairly good category. This value consists of the value of the technical aspect of 3.52 with a very good category, the value of the environmental aspect of 2.94 with a fairly good category, and the value of the socio-economic aspect of 2.48 with a rather poor category. Factors that influence the condition and performance of Communal WWTPs in Sleman Regency whose value is still less than expected are the maintenance of facilities with a value of 2.27, the load of wastewater with a value of 2.43, the institutional value of 2.47, and the management performance monitoring program with a value of 2.50 which falls into the rather poor value category.