Biodegradability improvement of penicillin formulation effluent by ozonation and the fenton reagents

Effects of ozonation and Fenton's treatment on the biodegradability of pharmaceutical wastewater originating from the Sultamycillin Tosylate Diydrate penicillin formulation was investigated. Process variables were ozone feed rates (127 - 2750 mg l^-1h^-1), ozonation pH as well as the type of Fenton's reagents (Fenton; Fe²⁺/H₂O₂ and Fenton-like; Fe³⁺/H₂O₂) applied at a fixed pH (= 3.0) and different Fe (0.5, 1 mM Fe²⁺ and Fe³⁺) and H₂O₂ concentrations (10, 20 mM). The efficiency of the selected pre-treatment systems was evaluated in terms of changes in COD (Chemical Oxygen Demand), TOC (Total Organic Carbon) and BOD₅ (5-Day Biochemical Oxygen Demand). The effect of chemical oxidative pre-treatment on activated sludge treatment performance was assessed in terms of microbial oxygen uptake rate (OUR) measurements conducted with unacclimated sewage sludge. Results have demonstrated that although similar overall COD (34 - 42 %) and TOC (24 - 36 %) removal efficiencies have been obtained by the ozonation process and the Fenton and Fenton - like reagents, only ozonation and Fenton-like processes were capable of completely eliminating the inhibitory effect of the penicillin formulation effluent on the microbial consortium in sewage sludge. Moreover, the Fenton-like and ozonation processes appeared to slightly enhance COD abatement rates by 4 % and 8 %, respectively, as could also be demonstrated in separate biodegradation experiments that were run with the raw, pre-treated formulation effluent in the same biosludge.