MAHD ZIA, SIRAJUDDIN AHMED AND ANIL KUMAR
Abstract
Acetogenesis of Fruit and vegetable wastes (FVW) was performed in a 250 ml batch reactor with semi continuous mode operation to study the effect of Temperature, Hydraulic retention time (HRT), organic loading rate (OLR) and nanomaterial waste on volatile fatty acids (VFA) production from FVW. Optimum conditions for enhancement of the acetogenesis process in order to obtain maximum VFA production were determined by varying the temperature, HRT, OLR and nanomaterial wastes in successive four cycles and studying their impact on concentration of VFA production and pH. In cycle 1, increase in temperature resulted in increase of VFA concentration with maximum VFA of 2316.88±185.19 mg/L obtained at 55p C. In cycle 2, increase in VFA concentration was observed with increase in HRT with maximum VFA of 2413.13±145.83 mg/l obtained at 7-day HRT, but the degradation rate was considerably reduced after 5 days which indicates process inhibition after 5-day HRT. In Cycle 3, VFA increased with the increase in OLR with maximum VFA concentration of 2951.67±137.12 mg/l obtained at an OLR of 1.4 gVS/l.d. However at OLR of 1.2gVS/l. d and 1.4 gVS/l.d the pH was reduced below 4.0 which could result in process inhibition. Use of 100 nm size Grade II iron oxide (Fe3O4) nanomaterial waste as a catalyst with FVW resulted in decrease of VFA concentration and was ineffective in enhancing the acetogenesis process.