ENVIRONMENTAL TECHNOLOGY, cilt.17, sa.7, ss.673-685, 1996 (SCI-Expanded)
Pseudomonas sp, isolated from the activated sludge of a petrochemical industry treatment plant was harvested and used as an inoculum culture for biological treatment of petrochemical wastewaters. The objective was the comparison of biological treatment efficiencies between Pseudomonas sp. added activated sludge and normal activated sludge taken from the full scale treatment plant. Experiments were carried out both in batch and continuous operations using a laboratory scale activated sludge system. Monod kinetic was used to determine kinetic coefficients from the experimental data of continuous operations. The maximum COD utilization rate constant (k), saturation constant (K-s), microbial decay rate (k(d)), yield coefficient (Y) and maximum specific growth rate (mu(max)) were determined to be 0.95 1/day, 199 mgCOD/L, 0.10 1/day, 0.30 mgMLSS/mgCOD and 0.285 1/day for normal activated sludge, respectively. These coefficients were also determined for Pseudomonas sp. added activated sludge system as 2.75 1/day, 1035 mgCOD/L, 0.08 1/day, 032 mgMLSS/mgCOD and 0.88 1/day, respectively. Removal efficiencies of GOD, TN and phenol for lower sludge ages were found higher for the Pseudomonas sp. added activated sludge system than that of the activated sludge system. Treatment efficiencies were found to be almost the same for both systems at high sludge ages.