The Use of Biofilter in Anaerobic Baffled Reactor to Improve Quality of Methane Concentration and Effluent as Liquid Organic Fertiliser

Abstract

The biofilter used is a simple technology in anaerobic digestion to remove pollutants from the substrate to enhance biogas production and nutrient effluent, which can be used as liquid organic fertiliser. This study aims to determine the effect of using a biofilter to improve biogas production and biogas effluent as an organic fertiliser material. The results show that the highest methane concentration is 60.64% at a dosage 200 L·day-1. The total solid (TS) content of biogas effluent exhibits a decrease of approximately 44% across all substrate doses, with respective percentages of TS of 0.16%, 0.03%, 0.025%, and 0.034% for 50 L·day-1, 100 L·day-1, 150 L·day-1, and 200 L·day-1, respectively. The use of biofilters in an ABR can significantly enhance the quality of biogas effluent, rendering it suitable for use as a liquid organic fertiliser. By capturing and biodegrading pollutants, the biofilter component can further enrich the nutrient content of the effluent, which already contains essential nutrients due to the anaerobic conditions and compartmentalised design of the ABR. The nutrient content in the biogas effluent mix with nutrition (AB mix) namely; N-total 262.5 mg·L-1, P-available 0.399 mg·L-1, Ca 4.08 mg. L-1, Mg 25.24 mg·L-1, Cu 0.032 mg·L-1, and Fe 13.09 mg·L-1 follows the standard organic fertiliser of the Minister of Agriculture of Indonesia.

Keywords

• tofu industry
• wastewater
• renewable energy
• anaerobic digestion
• organic waste
• fertiliser
• nutrient content