Acclimatization Process on Hybrid Upflow Anaerobic Sludge Blanket Reactor (HUASBR) using Bioball as Growth Media with OLR Variation for Treating Tofu Wastewater

Abstract

Wastewater of tofu industry contains very high organic content, then anaerobic process is the most suitable for degrading this liquid waste. The hybrid upflow anaerobic sludge blanket reactor (HUASBR) was applied in this study because it has the advantage in ensuring good contact between biomass and substrate where a suspension medium and anaerobic filter are able to withstand more biomass in the attached media. Processing Anaerobic process is carried out with the help of bacteria where bacteria need seeding and acclimatization. Acclimatization is the process of adaptation of microorganisms to wastewater to be treated. This adaptation process is carried out by adding waste water from the smallest concentration to the actual concentration. The purpose of this study is to determine the effect of variations in organic load rate (OLR) on the acclimatization process in removing COD, biogas production in accordance with the pH of the anaerobic degradation process so that the optimal process of the acclimatization process can be obtained. In this study, the acclimatization process took 200 days with variation of OLR in the range of 1.5 - 5.9 kg COD m-3 d-1 at HRT 24 hours and flow rate up (Vup) of 0.08 m/h. The objective of OLR variation was to evaluate acclimatization process on the HUASBR performance during process optimization. The highest biogas production and removal efficiency of COD were achieved in pH range of 6.5 - 7.6. While, the highest COD removal efficiency obtained was 86.57% on the 140th day and biogas production 7700 ml for OLR 4.8 kg COD m-3d-1 at HRT 24 h. Consequently, the optimum OLR for treating the tofu wastewater could be achieved up to 4.8 kg COD m-3d-1 and HRT 24h.