NAPHTHALENE BIODEGRADATION USING ACCLIMATIZED MIXED CULTURE FROM SEWAGE WASTE SLUDGE

Abstract

Naphthalene biodegradation using acclimatized mixed culture from sewage waste sludge was studied. Different initial Naphthalene concentrations (30to1000 mg/L) were used to evaluate the biodegradation rate of naphthalene. When the initial concentration of naphthalene increased from 30 to 1000mg/L the time required to utilize naphthalene increases from 2 to 21 days. The specific growth rate increases from 0.0092 to 0.0346 h-1 when the initial naphthalene concentration increases from 100 to 700 mg/L. Then the specific growth decreases to 0.0201 h-1 for 1000mg/L naphthalene concentration, indicating that there is an inhibitory effect on the microbial growth at high concentration. Different kinetic models for microbial growth, Monod’s, Haldane, Webb and Aiba were used. The experimental results confirm well with Haldane model as compared with the other models. Logistic models were used to describe the microorganism’s growth and the naphthalene degradation. A good fitting was obtained between the logistic models and the experimental data.