Treatment of food processing wastewaters by using Black Soldier Fly larvae: Preliminary results

The biological process based on the use of Black Soldier Fly larvae (BSFL) has emerged as an innovative treatment technology for high organic content (HOC) wastewaters (WW), such as those from food and beverage sector. The process offers both higher treatment efficiency and generation of larval biomass for resource recovery. This study provides the first insight into the suitability of real food-processing HOC-WWs to the BSFL treatment process. Six food-processing wastewaters were tested, such as from bakery, brewery, dairy, juice production, slaughterhouse, and winery. Preliminary evaluation of WW suitability was based on WW quality in terms of organic content, nitrogen, phosphorous and dominant macronutrients for larvae diet (proteins, carbohydrates, and lipids). The BSFL process performance was evaluated by monitoring larval development and removal of organic matter, nitrogen and phosphorous. Bakery, brewery and winery showed to be suitable for BSFL process, being characterised by high TOC concentrations and by good nutritional quality, achieving up to 93 %, 86 % and 95 % removal of TOC, COD and BOD respectively. This confirmed BSF process as an efficient technology for organics removal and bioconversion into larval biomass In contrast, dairy, juice, slaughterhouse samples, showed to not be suitable as single feeding. Nutritional quality can be improved by appropriate mixing of various type of WW.