Combining advanced oxidation processes with biological processes in organic wastewater treatment: Recent developments, trends, and advances
Bai Xiang-yu, Chao Li, He Shilong, Zhou Ji-ping, Jiajia Hu
Abstract
This review critically examines the integration of advanced oxidation processes (AOPs) and biological processes (BIOPs) for organic wastewater treatment, addressing key advancements, challenges, and future prospects. While AOPs excel in degrading recalcitrant pollutants through hydroxyl/sulfate radicals, their high energy demands and incomplete mineralization limit standalone applications. Conversely, BIOPs offer cost-effective mineralization but struggle with toxic or non-biodegradable compounds. Our analysis reveals that sequential AOPs-BIOPs systems significantly enhance biodegradability (e.g., ozonation increased BOD5/COD ratios from 0 to 0.8) while reducing treatment costs by 40-60% compared to full AOP mineralization. Chemical pre-treatment modes (e.g., Fenton/ozonation + bioreactors) demonstrate 85-93% COD removal efficiency for complex industrial effluents, though challenges persist in managing halogenated byproducts and residual oxidant toxicity. Emerging strategies combining non-radical AOPs with salt-tolerant microbial consortia show promise for high-salinity wastewater. Critical barriers include scale-up inefficiencies, where biological reactor performance declines by 20-30% during industrial translation, and the need for standardized biodegradability assessment protocols. Future research priorities should focus on (1) integrated reactor designs for synergistic radical-microbe interactions, (2) AI-driven dynamic parameter optimization, and (3) advanced toxicity profiling of transformation products. This work establishes a framework for designing energy-efficient hybrid systems to meet increasingly stringent wastewater discharge standards.