Enhancing volatile fatty acid production from food waste by H2O2-moderate temperature thermal pretreatment: Treating waste with waste in coal mining areas

Abstract

Supplementing carbon sources in sewage treatment plants with organic matter from food waste is crucial for resource recycling in coal mining areas. In this study, a moderate-temperature H2O2 method was used to pretreat food waste from a coal mining area. The changes in the properties of the pretreated food waste and their influence on volatile fatty acids (VFAs) production during anaerobic fermentation were investigated. Additionally, the nitrogen and phosphorus removal rates obtained when glucose and fermentation slurry of food waste (FSFW) were used as carbon sources in the sewage treatment system were compared. Compared with untreated food waste, the soluble chemical oxygen demand (SCOD) increased by 58 % after pretreatment with 0.25 % H2O2 at 60 ℃, and the viscosity and oil content decreased significantly, which caused VFAs production to increase from 15,267 mg COD/L to 50,774 mg COD/L. When the H2O2 concentration increased to 2.0 %, the SCOD increased to 153 %, and the viscosity and oil content further decreased, but the VFAs production decreased to 7477 mg COD/L. This occurred because large quantities of ammonia nitrogen was formed at higher H2O2 doses, which inhibited VFAs formation. Moreover, the nitrogen removal rate was higher when FSFW was used as a carbon source than when glucose was used as a carbon source.