Development of an Advanced Treatment System using Biofiltration and an Ozone-AOP for Agricultural Water Reuse

Nutrient level s in wastewater treatment plant effluent can limit water reuse options, especially as a resource for surface recharge, because of the threat of eutrophication. A biofiltration and ozone-AOP process was evaluated for the removal of nutrients, including total nitrogen and total phosphorus (TN, TP), and also non-biodegradable organics from a secondary treatment system in a 1,000 m 3 /d full-scale plant over the course of one year of operation. The average effluent quality during this year was as follows: TN 3.0 mg/L, chemical oxygen demand (COD Cr) 7.0 mg/L, TP 0.05 mg/L, suspended solids (SS) 0.73 mg/L, and biological oxygen demand (BOD 5) 1.6 mg/L. The effluent quality was able to meet South Korea’s stringent discharge limits and water reuse requirements. Overall, the advanced treatment system using biofiltration and an ozone-AOP is able to achieve very low effluent nutrient levels and a high removal efficiency of non-biodegradable organic and trace organic contaminants, providing high water quality for surface water recharge.