OPTIMIZATION OF PROCESS PARAMETERS IN TREATMENT OF BREWERY EFFLUENT

A three- variable Box-Behnken design (BBD) coupled with response surface methodology (RSM) was employed to optimize and evaluate the effect of adsorbent dose, contact time and temperature on percentage reduction of BOD, COD and TDS in brewery effluent. Adsorbent was prepared from coconut shell, which was carbonized at temperature of 600°C for 2 hours and thereafter activated. The effluent was treated with the adsorbent by varying three variables: adsorbent dosage (1-5 g), contact time (40-180) and temperature (30-40°C). Statistical analysis of the results showed that all the factors, except the temperature, had significant effect on the responses Quadratic models were developed for percentage reduction of (biological oxygen demand) BOD, chemical oxygen demand (COD) and total dissolved solids (TDS). The models were significant with p < 0.0001 and showed a good fit to the experimental data. The percentage reduction of BOD, COD and TDS were positively influenced by adsorbent dose and contact time. The temperature range used for this study did not have so much effect on the responses. The optimum conditions for BOD, COD and TDS reduction of 75.268%, 69.865% and 69% respectively were adsorbent dosage of 5g, contact time of 180 minutes and temperature of 34.4°C.