Investigation of Blended Seaweed Waste Recycling Using Black Soldier Fly Larvae

Seaweed waste is often found in the coastal areas of Indonesia. Along with other waste, large quantities of seaweed will disrupt the ecosystem and harm the surrounding environment. Therefore, treating seaweed waste effectively and efficiently is necessary to mitigate such adverse effects. This study processed seaweed waste using Black Soldier Fly (BSF) larvae to accelerate waste degradation, reducing the waste buildup. The characteristics of waste, the feeding treatment, chemical content, and parameters of waste processing were assessed. Based on the results, seaweed waste contains highly organic compounds, potentially used as fertilizer or animal feed. The feeding method demonstrated that the mass of BSF larvae increased according to the intensity of the feeding treatment. The total waste degradation obtained from the BSF larvae was 72.61% with a waste reduction index of 1.87 g/day, and the efficiency of digested feed was 7.61% with feeding treatment every three days. The chemical composition of BSF pre-pupae, pupae, and residues was also evaluated to determine their feasibility as animal feed and biomass. The results suggested that pre-pupae and pupae comprise protein, fat, calcium, and phosphorus. At the same time, the waste residue has a C-organic and N-organic ratio of 13%–14% and is an alternative for future waste-to-energy applications. Overall, BSF offers a great prospect in generating high-value products and simultaneously serves as a strategy for efficient waste management.