Application of the honeycomb anaerobic biodigester (honeycomb biodigester) in Tofu industrial wastewater treatment

The characteristics of tofu whey wastewater are a high organic component content, which is classified as a severe environmental pollutant, posing harm to the environment. The research focused on designing and implementing a honeycomb anaerobic biodigester (Honeycomb Biodigester) for tofu whey processing. The research methodology involved the initial design of the Honeycomb Biodigester, which was based on a 120-liter cylinder with a honeycomb biofilter (hexagonal structure) made from activated carbon on a corrosion-resistant (PE) plate. The Honeycomb Biodigester was then applied in the tofu whey processing, starting with the acclimatization stage using a starter mixture of cow dung, water, and tofu whey (3:1:1) for 21 days. Subsequently, tofu whey was gradually added every day for 30 days. The measured parameters included volatile solids (gravimetry), volatile fatty acids (steam distillation/titrimetric), pH (pH meter), organic compound content using a GC-MS tool, and biogas/combustible gas content (smart sensor ST8900). The research results indicated that the microorganisms (MO) exhibited resilience under volatile fatty acids (VFA) conditions of 5693 mg/L and pH 7.8. The microorganisms demonstrated synergistic activity with fluctuations in volatile solids (VS/substrate) levels, showing a decrease from 74% to 53% in non-methanogenesis (MO non-methanogenesis) and changes in VFA (methanogenesis substrate) ranging from 5693 to 1024 mg/L. On the 21st day, the biogas (light gas) yield was approximately 64 percent. The performance of the honeycomb in the biodigester effectively controlled washed-out biomass, with zero percent detection of organic compound content on GC-MS at the slurry output of the Honeycomb Biodigester.