Synergistic removal of drugs in wastewater from traditional Chinese medicine processing using industrial-scale ozone cavitation

Traditional Chinese medicine (TCM) production generates wastewater containing high level of morphine, codeine, and other opioids. Our field investigations at TCM factories revealed that existing activated sludge systems, though may be compliant for other chemicals, exhibit limited removal efficiency for these recalcitrant contaminants. Consecutive daily monitoring of effluent showed morphine persistently at concentrations ranging from 37,029-301,623 ng/L due to incomplete biodegradation, posing a significant disruption to aquatic environment and its further wastewater-based surveillance in public security. To address this challenge, we developed an advanced hydrodynamic cavitation-ozonation system (HC/O₃), incorporating a novel negative-pressure reactor configuration. Under optimized conditions (1.5 L/min ozone inflow, 4 mg/L ozone concentration), the system achieved 94% removal of morphine within one hour, with a synergy index of 1.46 demonstrating remarkable process enhancement. Distinct from prior laboratory-scale investigations limited to model pollutants, this work validated HC/O₃ performance treating six psychoactive substances in compositionally variable TCM wastewater, demonstrating scalability and robustness under real-world operating conditions. Over a 5-day continuous trial with variable influent compositions, the HC/O₃ system demonstrated robust adaptability, consistently achieving 99.9% removal of morphine and thebaine within 3 h, specifically at 94% removal for morphine-specific reduction within first hour. The operational costs of 5.38 USD/m³ and energy efficiency reflected in a 1.11 × 10^-7 mg/J cavitational yield. This result indicates potential economic viability and technical robustness of this integrated solution for industrial implementation, under the tested conditions. The HC/O₃ process establishes a new approach for treating pharmaceutical-laden wastewater, simultaneously reducing environmental risks for aquatic ecosystems and potentially improving the reliability ofwastewater-based surveillance.