The treatability of pharmaceutical wastewater collected from penicillin-G manufacturing unit in Cuddalore, Tamil Nadu, India was investigated using an upflow anaerobic sludge blanket (HUASB) reactor . The reactor was operated at an ambient temperature of 30 to 35°C for 113 days at 11 organic loading rates (OLR) at 24 h hydraulic retention time (HRT). After the start up period, acclimatisation was done with the substrate using nutrients at five different organic loading rates (OLRs), viz., 1.680, 2.245, 2.324, 2.532 and 2.686 kg COD m-3 d-1, the steady state values of COD removal efficiency were 54.60, 73.54, 84.77, 86.15 and 92.34%, respectively, on days 7, 14, 22, 30 and 41. After acclimatisation, nutrients supplement was discontinued. Thereafter, raw effluent was used at six different organic loading rates viz., 0.949, 1.560, 2.106, 3.084, 4.0 and 5.0 kg COD m-3 d-1 to evaluate the performance of the reactor. For these six OLRs, the initial substrate concentrations were maintained at 949, 1560, 2106, 3084, 4000 and 5000 mg COD/l and the corresponding treatment efficiencies were found to be 77.96, 83.95, 88.60, 91.025, 95.0 and 75.51%, respectively. It is, from the results obtained, evident that the initial substrate concentration of 4000 mg COD/l is best suited for achieving a greater reactor performance. Through out the study, the pH value of the effluent remained almost same and it ranged between 7.4 and 8.0 except for the first few days, indicating a stable anaerobic environment in the reactor. The experimental data obtained were modeled by adopting the adaptive neuro-fuzzy inference systems (ANFIS). The statistical quality of the ANFIS modeling was high (R2 = 0.9718 and 0.9268 for 0-41 days and 42-113 days, respectively, between experimental and simulated values). Furthermore, it was also observed that there was a one to one correlation among the simulated and observed COD values.
Keywords: Pharmaceutical wastewater, HUASB reactor, Modelling, OLR
