Wastewater treatment of hospital laundry by advanced oxidation process: UV/H ₂ O ₂

ABSTRACT

The objective of this work was to evaluate the treatment of hospital laundry effluents by advanced oxidation process UV/H₂O₂. Factorial design 3² was employed to investigate the influence of pH and peroxide dosage on treatment efficiency. The photo-oxidation experiments were performed with effluents collected in the laundry of the Regional University Hospital of Maringá (HUM). Physicochemical parameters of effluent color, turbidity, BOD, surfactants and quantification of total and thermotolerant coliforms are presented in this study. Three values ​​of pH - 5, 7 and 9 - and three dosages of hydrogen peroxide with [COD]:[H₂O₂] ratios of 1:0.5, 1:2.5 and 1:5 (w:w) were tested. The best results were achieved with the treatment performed at pH 9 and ratio [COD]:[H₂O₂] of 1:2.5. The average removal efficiencies of COD and surfactants were 60.3 and 98%, respectively. However, the treatment was not efficient in reducing color and turbidity, demonstrating the need to combine complementary treatments for the reduction of such parameters.

Keywords:
wastewater; hospital laundry; effluent treatment; advanced oxidation process; UV/H₂O₂