USE OF SEQUENTIAL BATCH REACTOR FOR TREATMENT OF PHENOLIC WASTEWATER

Abstract

The aim of this research is to study the treatment of 4-chlorophenol bearing wastewater by biological treatment in an SBR without any adsorbent (blank SBR) and an SBR loaded with Granular activated carbon (GAC-SBR). The performance of two types of SBR's has been compared in terms of treatment of 4-chlorophenol (4-CP) bearing synthetic wastewater. Adsorbent dose used for GAC-SBR was 16 g/L. The test results revealed that GAC addition could improve the activity of the activated sludge. The GAC-SBR could treat 4-CP bearing wastewater with initial concentration of up to 1250 mg/L while blank SBR could treat 4-CP bearing wastewater with initial concentration of only up to 200 mg/L. Also by addition of adsorbent to SBR, the removal efficiency of SBR was increased from 75% (approx.) to more than 95%. It was observed that addition of GAC could enhance the ability of activated sludge in resisting the shock load of organics. Compared to the blank activated sludge, GAC added activated sludge could treat wastewater of significantly higher 4-CP concentration in a shorter cycle time. Characterization of the sludge was done using SEM/ EDX analysis. Settling and filterability characteristics of the sludge were also studied. In addition to this, experiments were carried out to study the adsorptive removal of 4-chlorophenol using GAC as adsorbent