Phenol biological treatment in wastewater by laboratory scale

Abstract

Experiments used an aerobic-activated sludge reactor to investigate the removal of phenol and formaldehyde from wastewater on a laboratory scale. An activated sludge reactor module with a volume of 70 L, starts up with 10 hours of hydraulic retention time pH value in the range of 6.8-7, the DO in the anoxic compartment is always less than 0.5 mg/L, in the aerobic compartment between the values of 3.0 and 4.5 mg / L. The results showed that the activated sludge after the start-up process was stable with MLSS 2800 mg/L to 3170 (mg/L), sludge volume index (SVI30) was 156.7 ml/g, and activated sludge showed good sedimentation ability. Phenol in influent less than 200 mg/L, the removal performance of activated sludge reactor is very good, almost all phenol is removed from the wastewater. When treating wastewater with a mixture of phenol and formaldehyde, there is a reduction in treatment efficiency when increasing the pollutant concentration, at a concentration of 300 mg/L of formaldehyde and phenol, only 82.36%. and 72.63% respectively is eliminated. Activated sludge reactor can be used to treat industrial phenol and formaldehyde-containing wastewater.

Keywords: Activated sludge reactor; industrial wastewater; phenol removal