Abstract:
Phenols are a group of waste products which cause serious taste and odour problems in water. The major industries producing phenolic wastes are oil refineries, coke oven plants, steel plants etc. Acceptable discharge limits for phenols vary depending on the nature of the phenols, the volume and the rate of discharge and the nature and volume of receiving water.
Treatment methods applicable to phenol removal include biological (activated sludge, trickling filter, oxidation pond and lagoons); chemical oxidation (air, chlorine, chlorine dioxide, ozone and H202); Physical (activated
carbon adsorption, solvent extraction and ion-exchange) and physico chemical
(incineration and electrolytic oxidation).
Activated sludge techniques are reported to be effective for phenol levels as high as 'thousands' mg/I, However in view of the high capital requirements for biological oxidation the method is most cost effective with high volume effluents.
Phenols are not among those organic wastes which are readily biodegrabable. To degrade the phenol the microorganisms were developed in the, present study. These microorganisms were able to survive in the phenolic solution. These microorganisms used phenol as their food.
(iii)
