Removal of Nitrogen and Phosphorus from Wastewater by Modified Pyrite in a Sequencing Batch Reactor (SBR)

¹ School of Environment and Energy Engineering, Anhui Jianzhu University, Hefei 230601, China
² Key Laboratory of Water Pollution Control and Wastewater Reuse of Anhui Province, Hefei 230601, China
³ Key Laboratory of Huizhou Architecture in Anhui Province, Hefei 230601, China

^* Corresponding Author: Wei-Hua Li; email: liweihua9@126.com;

Abstract

The removal efficiency of nitrogen and phosphorus is challenging in the conventional biological nitrogen and phosphorus removal processes. In this study, the modified pyrite was used as the fillings of se-quencing batch reactor (SBR) in order to improve the efficiencies of nitrogen and phosphorus removal from wastewater. The results showed that SBR with the modified pyrite could significantly improve the removal efficiencies of nitrogen and phosphorus when compared with that in SBR without fillings (control SBR). The average influent ammonia nitrogen (NH₄⁺-N) and total phosphorus (TP) were 6.96±0.17 mg L^-1 and 6.94±0.01 mg L^-1, respectively. The average NH₄⁺-N and TP removals of modified pyrite constructed SBR were 49.65±19.49% with 3.54±1.31 mg L^-1 of average effluent NH₄⁺-N and 76.20±6.55% with 1.84±0.46 mg L^-1 of average effluent TP, respectively. While the average NH₄⁺-N and TP removal efficiencies of con-trol SBR were only 34.76±11.28% and 56.28±0.11%. The mechanisms of the SBR with enhanced simulta-neous nitrogen and phosphorus removals might be anaerobic and aerobic oxidations of modified pyrite, and phosphorus retained in the SBR of modified pyrite was mostly in the form of Fe-bound-P.