Investigation of hospital wastewater treatment using the UV/H2O2/S2O82- process as a combined AOP method

Abstract

Hospital wastewater contains microorganisms, heavy metals, toxic chemicals, and different drugs that might be treated insufficiently or not at all before they enter municipal wastewater, causing numerous problems for humans and other living organisms. The aim of this study was to assess the performance of the UV/H2O2/S2O82- process in the treatment of hospital wastewater. This process has been modelled and optimised using the statistical response-surface method (RSM), and the regression analysis showed that the data were well-fitted with a second-order polynomial equation. Based on the model, the biochemical oxygen demand (BOD) removal efficiency can reach 93.2% in optimal conditions of pH = 3.1, H2O2 dosage of 203.1 mg/L, and NaPS dosage of 44.7 mg/L. The results showed that in the presence of both persulphate and hydrogen peroxide, the process efficiency was higher in acidic conditions and in the range of the design experiment, more oxidants had more efficiency. Turbidity, total Kjeldahl nitrogen (TKN), total organic carbon (TOC), total coliform, and E. coli were also studied as supplementary parameters, and removal efficiencies of about 78.53%, 70%, 52%, 99%, and 99.8% were achieved, respectively. Kinetic studies revealed that the data were well-fitted with the second-order kinetic model and had a regression coefficient of 0.97 and a rate constant of 0.0018 (L/mg min).