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.

The herculean imprecation of nitrogen-based pollutant like Ammoniacal Nitrogen (AN) and Chemical Oxygen Demand (COD) on aquatic milieu is now a concern for the Dye, pharma and fertiliser industries. Wastewater from these is characterised with high concentration of AN, COD and Total Dissolved Solids (TDS), treatment of which is of utmost importance for cleaner environment. In the current research work, an attempt was made to apply integrated Electro-coagulation (EC) – Sonication process for the removal of COD and AN from highly acidic dye intermediate wastewater containing high to very high concentration of COD and AN. Systematic laboratory experiments were conducted for the treatment of dye intermediate wastewater and influences of pH (5–11), applied voltage (0.5–4V) and electrolysis time (30–120 minutes) were investigated.