Pilot-scale treatment of pharmaceutical berberine wastewater by Fenton oxidation

Fenton oxidation was used to treat the berberine finished mother liquor wastewater in pilot scale. To evaluate berberine and COD removal efficiency, the main factors, including pH, H2O2 dosage, Fe2+/H2O2 mass ratio and the water flow (Q), were optimized using response surface methodology (RSM). The results showed that under the optimal conditions, pH 3, H2O2/COD molar ratio of 1.25, Fe2+/H2O2 molar ratio of 0.1, Q 100 L/h [with hydraulic retention time (HRT) of 2.5 h], the COD and berberine removal efficiencies were 35.6 and 91.4 % at initial COD concentration of 4061 mg/L and berberine concentration of 709 mg/L, respectively. The (BOD5)/(COD) ratio (B/C) of the wastewater increased from 0 to 0.3, indicating significantly improved biodegradability of wastewater.