doiSerbia

Recovery of UAPB from high organic load during startup for phenolic wastewater treatment

Bakhshi Zeinab (Babol Noshirvani University of Technology, Department of Civil Engineering, Babol, Iran)
Najafpour Ghasem (Babol Noshirvani University of Technology, Department of Chemical Engineering, Babol, Iran)
Navayi Neya Bahram (Babol Noshirvani University of Technology, Department of Civil Engineering, Babol, Iran)
Kariminezhad Esmaeel (Babol Noshirvani University of Technology, Department of Civil Engineering, Babol, Iran)
Pishgar Roya (Babol Noshirvani University of Technology, Department of Civil Engineering, Babol, Iran)
Moosavi Nafise (Babol Noshirvani University of Technology, Department of Civil Engineering, Babol, Iran)

Biodegradation of synthetic wastewater containing phenol by upflow anaerobic packed bed reactor (UAPB) was studied in this work. The reactor was operated at a hydraulic retention time (HRT) of 24 h and under mesophilic (30±1ºC) conditions. The startup operation was conducted for 150 days; split into 4 phases. The phenol concentration was stepwise increased. The concentration of phenol in phases 1, 2, 3 and 4 were 100, 400, 700 and 1000 mg/l, respectively. In phase 1, the reactor reached steady state conditions on the 8th day with a phenol removal efficiency and biogas production rate of 96.8% and 1.42 l/d, respectively. For an increase of the initial phenol concentration in phase 2, a slight decrease in phenol removal efficiency was observed. Similar trends were observed in phases 3 and 4 of startup. Due to the high phenol concentration a sudden decrease in removal efficiency and biogas production was observed. The surviving microorganisms were gradually adapted and acclimated to high phenol concentrations. In phases 3 and 4, the phenol removal efficiency at steady state conditions were 98.4 and 98%, respectively. The maximum biogas production was observed at day 130 with a value of 3.57 l/d that corresponds to phenol concentration of 1000 mg/l.

Keywords: phenol, upflow anaerobic packed bed, biogas, biodegradation, startup