Combined ultrasound cavitation and persulfate for the treatment of pharmaceutical wastewater

In recent years industrialization has caused magnificent leaps to the high profitable growth of pharmaceutical industries, and simultaneously given rise to environmental pollution. Pharmaceutical processes like extraction, purification, formulation, etc. generate a large volume of which wastewater contains high Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD), auxiliary chemicals, and different pharmaceutical substances or their metabolites in the active or inactive form. Its metabolites impart non-biodegradable toxic pollutant as a byproduct and intensive color, which increases ecotoxicity into the water, thus it requires a proper treatment before being discharged. This study focuses on the feasibility analysis of the utilization of ultrasound cavitation (20 kHz frequency) assisted with persulfate oxidation approach for the treatment of complex pharmaceutical effluent. Process parameters like pH, amplitude intensity, oxidant dosage was optimized for COD removal applying response surface methodology-based Box Behnken design. The optimum value observed for pH, amplitude intensity and oxidant dosage are 5, 20% and 100 mg/L respectively with 39.5% removal of COD in 60 min of fixed processing time. This study confirms that a combination of ultrasound cavitation and persulfate is a viable option for the treatment of pharmaceutical wastewater and it can be used as an intensification technology in existing effluent treatment plants for the achieving highest amount of COD removal.

Automated summary

Industrialization has led to the high profitable growth of pharmaceutical industries but also caused environmental pollution. This study focuses on the treatment of complex pharmaceutical wastewater using ultrasound cavitation and persulfate oxidation. The optimized process parameters showed a high COD removal rate, indicating the feasibility of this combined treatment method.