Digestate Post-treatment and Upcycling: Unconventional Moisturizing Agent for Food Waste In-Vessel Composting

Abstract Nowadays, Tunisia faces challenging environmental and energy issues which relate mainly to the implementation of an appropriate solid waste management system capable dealing with high production biowaste on one hand, increased need for water resources other. Therefore, current study is intended develop a closed cycle technical concept treating food (FW) through combined biological processes. In this approach, FW anaerobic digestion (AD) was destined provide valuable input material in vessel-composting by exploiting produced digestates. To end, gathered AD-effluents three systems (D1, D2, D3) were entirely analyzed select, as further step, most suitable be subject suggested post-treatment. Hence, several physiochemical parameters examined key performance indicators. It consisted moisture content, pH, C:N ratio heavy metals contents. The findings depicted that generated digestates characterized content inspired its utilization unconventional moisturizing agent (MA) aiming reduce fresh consumption during composting process. Thus, two experimental setups carried out evaluate effect selected digestate FW-in-vessel process performance, non-standard MA inserted A2, comparing unamended (A1) moistened water. fact, basing above-mentioned criteria, relatively (of around 15), well significant rate required macro- micro-nutrients promoted exploitation biochar-rich (D3) not only efficient MA, but also booster. Furthermore, results revealed addition D3 improved significantly terms steering including attained temperature, MC pH. When it comes maturity stability assessment, decreased profiles ratio, nitrification index (NI), respiration activity (AT4) ascertained fulfilment conditions both A1 A2 produce stable mature end-products. However, regarding compost quality, concentrations met requirement set German standards attested highly-qualified products, rated class B A, respectively. noteworthy mention even classified “inappropriate substrate” composters, criteria applied directly land liquid biofertilizer. This latter ascertained, additionally, efficiency feasibility sustainable management. Graphic