dc.description.abstract | Biogas is an alternative energy that can be used as a substitute for fossil fuels. Biogas can be produced from the fermentation of organic matter carried out anaerobikally. Vegetable waste is organic material that can be used as raw material for biogas production. . In addition to the availability of abundant, this waste also has a suitable C/N ratio if added to other materials like cow dung. This study aims to evaluate the utilization of vegetable waste as raw material and comparing the effectiveness of biogas circulation and non- circulation in biogas production and rate of decline COD. Fermentation process conducted in anaerobik digester that have volume 50 Liter for digester with leachate circulation and volume 25 liter for digester without leachate circulation. Fermentation process is done by using the starter of cow dung 20 % of the total material volume for 40 days. Specific production of biogas from digester circulation by controlled pH is 219 L/kg TS of material with rate of decline COD is 24 %, digester circulation without pH control is 117 L/kg TS of material with rate of decline COD is 28 %. Meanwhile, biogas specific production in the digester without leachate circulation have specifik biogas production and rate of decline COD lower than digester with leachate circulation.the spesicific biogas production is 24 L/Kg TS with rate of decline COD is 18 %. The highest specific of biogas production is conducted by digester with leachate circulation and pH control. Leachate circulation and pH control have considerable influence of biogas production. | en |