Removal of Nitrate and Phosphate from Wastewater Effluent using Packed-Bed Bioreactor Filled with WoodChips, Coastal Sands, and Crushed Seashells

Nitrate and orthophosphate in wastewater effluent have a considerable impact on the nutrient load of water bodies. Therefore, the discharging of nitrogenous and phosphorus compounds into water resources induces water pollution. The present study aimed to investigate the performance of natural materials in removing nitrate and orthophosphate from the effluent of a wastewater treatment plants. For this purpose, four laboratory-scale bioreactors with different combinations of filter materials, including woodchips (W), woodchips-beach sand (WS), woodchips-seashells (WSS), and woodchips-beach sand-seashells (WSSS) were applied to assess the performance of nitrate and orthophosphate removal in three hydraulic retention times of 12, 18 and 24 hr. The results showed that the highest removal performance of nitrate and orthophosphate belongs to the WSSS treatment by 92.19 and 96.57%, respectively. In addition, the retention time of 18 hr had the best performance in removing nitrate and orthophosphate in all bioreactors. The research findings revealed that the woodchips in combination with modifier materials have a excellent performance to remove nitrate and orthophosphate.