Phenol removal through combined biological and enzymatic treatments

Abstract

-This work studies the use of biological and combined biological/enzymatic treatments in phenol degradation. The systems studied were conventional batch aerobic biological followed or preceded by enzymatic treatment. Tyrosinase extracted from the mushroom Agaricus bispora was employed. Biological treatment efficiently degraded effluents containing up to 420 mg.L -1 of phenol, removing 97% of the COD and 99% of the phenol in 48-hour batches. Alterations in phenol concentration intake reduced treatment efficiency significantly. Enzymatic polishing of biotreated effluent removed up to 75% of the remaining phenol in a four-hour reaction with 46 U.mL -1 of tyrosinase and 50 mg.L -1 of chitosan (used as coagulant). Enzymatic pretreatment with 20 U.mL -1 of tyrosinase reduced the phenol concentration by 25 % after 2 hours of reaction, although initial COD increased up to 58%. The subsequent biological treatment of that enzymatic pretreated effluent reduced COD to 151 mgO 2 .L -1 and phenol concentration to 1 mg.L -1 in 24-hours batches.

Endocrine disrupting compounds removal from wastewater, a new challenge

“…Treatment of wastewater and sludge contaminated with phenols and other aromatic compounds (e.g., BPA, bE2, and EE2) with enzymes such as peroxidases [137][138][139][140] or polyphenol oxidases [139,141,142] is a new and interesting strategy. Since current researches develop the production of enzymes by using municipal and industrial wastewater and sludge, as basic substrate, the overall costs of enzyme production would be reduced [143].…”

Phenol removal from wastewaters by electrochemical oxidation using boron doped diamond (BDD) and Ti/Ti0.7Ru0.3O2 dsa® electrodes

“…Biological treatment of polluted water is the most economical process and it is used for the elimination of biodegradable organic pollutants present in wastewater; however, when the wastewater contains toxic and refractory organic pollutants, other processes must be employed ( Bevilaqua et al, 2002;Azevedo et al, 2009). One interesting possibility is to couple partial oxidation and biological treatment in order to decrease the toxicity and to increase the biodegradability of the wastewater before biological treatment (Palmas et al, 2007;Anglada et al, 2009).…”

Ultrasound assisted enzymatic degradation of diclofenac sodium: Optimization of process parameters and kinetics

“…The benefits of enzymes over the conventional chemical oxidation and/or biological treatment comprise absence of toxic effects, easy and simple process control, lack of unforeseen products generation because of their high specificity, lack of acclimatization period, less energy requirement as well as operability over a wide temperature, pH and salinity at low or high concentrations of pollutants which exhibit attractive replacement for conventional wastewater treatment [15][16][17][18].…”