Analisis Keberlanjutan Produksi Biogas dari Limbah Cair Tahu Menggunakan Pendekatan Composite Indicator: (Studi Kasus di Pabrik Tahu Giriharja, Sumedang)

Abstract

Tofu industries in Indonesia was dominated by Small Medium Enterprices (SMEs) that not implemented wastewater treatment due to several limitation, such as technological knowledge and cost. However, various grant had been given, one of which was from Lien Fooundation and NEWRICOMM, Singapore that colaborated with Research Center for Environmental and Clean Technology, BRIN to install Wastewater Treatment Plant (WWTP) in Giriharja. Several biogas project grants were no longer operated, indicating the importance of sustainability assassment. Since, 70% management control came from post installation that played important roles for the capability of WWTP to run normall. In this study, composite indicator (CSI) was used due to their ability to assess the effectiveness, efficiency, and the impact of biogas production in WWTP. A composite indicator is formed when individual indicators were compiled into a single index, on the basis of an underlying model of the multi-dimensional concept that being measured. Using CSI, the different of measurement units from indicators could transformed as unitless by normalization and thourgh aggregation would be obtained a composite values from several indicators. This study was conducted in Giriharja WWTP, where treated tofu wastewater from 9 SMEs with 2,014 kg soybean/day. The WWTP could produced biogas which used as cooking energy by the households. The aim of this study was to assess sustainability of biogas production in WWTP using Composite Indicator (CI), steps: i) selection and assessment of indicators, ii) CSI assessment, and iii) impact evaluation. The selected indicators were 2 Environment indicators (waste managment and clean production (water quality) dan Green House Gas (GHG) emmision; 5 Social indicators (public acceptance, odor, visual impact, technological complecity, and bioenergy used to expand access modern energy service); and 3 Economic indicators (productivity, net energy balance/NEB, energy diversity). Indicator values from baseline scenario in GHG was 5.67 Gg-CO2 eq/year without COD reduction. Public acceptance, odor, and visual impact values were 96.15%; 90.38%; and 90.38% respectively. Meanwhile, energy diversity was 0.92 with energy comsumption composition LPG+biomassa dan LPG were 4 and 96% respectively. Biogas scenario showed 3.17 Gg-CO2 eq/year GHG emission with COD reduction effesiency was 93.35%. Public acceptance, odor, and visual impact values were 69.23%; 9.62%; dan 13.46% respectively. Biogas scenario values has higher technological complecity than baseline (LPG), hence the biogas production gave acecible of modern bioenergy for 49.32% of respondents. The biogas productivity was 0.13 MJ/m3 wastewater with NEB values 124.48 MJ/ton tofu wastewater and the ratio efficiency of anaerobic digester operation valued 55.04. Energy diversity valued 0.59 with energy comsumption composition: LPG, Biogas+LPG, and Biogas were 26, 72, and 2% respectively. CSI value on environment for biogas scenario (0.30) had higher sustainability than baseline (0.01) with the implementation of tofu wastewater managment. Social dimension high influenced by the higher weight of technological complecity. Meanwhile, economic sustainability of biogas scenario (0.11) higher than baseline (0.01). The impact of biogas production from environment sustainability perspective could reduce GHG emission 2.50 Gg-CO2 eq/year which indicated the improvement of environment. In social dimension, biogas scenario impact could reduce odor and river pollution. Regarding the performance of WWTP, could produced biogas 59.25 m3/day. According to the energy ratio and the performance of cut-off in GHG, and the improvement of river condition which represented by the reduction of public protest showed the sustainability of biogas production in Giriharja WWTP could be met by the implementation of tofu wastewater management hence of discharge directly to the river.