A KINETIC-MODEL OF A RECIRCULATED UPFLOW ANAEROBIC SLUDGE BLANKET TREATING PHENOLIC WASTE-WATER

Sludge taken from a recirculated upflow anaerobic sludge blanket (RUAS B) treating phenolic wastewater at organic loadings of 6, 12, 16, and 20 kg COD/m(3) day was tested by the biochemical methane potential (BM P) method at intervals over a three-year period for an accurate determ ination of the specific gas production rate. A modified version of the Haldane equation was used in the selection of a statistically signifi cant model describing this process. Statistical diagnosis was carried out with student t-test, Durbin-Watson test for two-tail distribution and Kalmogorov-Smirmov statistical approach. The estimated ranges of t he maximum specific reaction rate, K; saturation constant, K-s; inhibi tor constant, K-i; and the order of inhibition, n were as follows: 280 -764 mt biogas/g VSS-day, 202-398 mg phenol/L, 516-880 mg phenol/L, an d 1.47-2.51, respectively. The physical meaning of these parameters is explained. BMP tests with sludge taken from the recirculating upflow anaerobic sludge blanket (RUASB) bioreactor running at a loading of 14 kg COD/m(3) day validated the effectiveness of the selected model thr ough comparisons of experimental data and predictions. The results ind icate that model predictions accurately reflect experimental data with in one standard deviation.