Simultaneous Nitrogen and Phosphorus Removal from Organic Sewage Using Sequencing Batch Biofilm and Electrochemical Reactors

• Published in: International journal of electrochemical science Vol. 17; no. 5; p. 220533
• Main Authors: Wang, Yue, Choi, Hyeoksun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.05.2022
• Subjects: Aerobic; Anaerobic; Anoxic; Electrochemical treatment; Nitrogen; Phosphorus; Sequencing Batch Biofilm Reactor; Sequencing Batch Biofilm Reactor; Aerobic; Electrochemical treatment; Phosphorus; Nitrogen; Anoxic; Anaerobic
• ISSN: 1452-3981; 1452-3981
• DOI: 10.20964/2022.05.09

The time of anaerobic, aerobic, and anoxic processes was optimized in this study as an important factor to overcome carbon source deficiency, time-consuming, high energy consumption, and high cost of sequencing-batch biofilm reactor (SBBR) processes for simultaneous removal of phosphorus and nitrogen in organic sewage treatment in the SBBR method. The anaerobic/aerobic and anaerobic/aerobic/anoxic phases of the SBBR operation for wastewater treatment were separated. In the SBBR system, K3 was used as a biofilm carrier. The results showed that the optimal time for a stable operation cycle in an SBBR system can be 5, 90, 210, 90, 20, 15 and 10 minutes for fill, anaerobic, aerobic, anoxic, settle, draw, and idle, respectively, and that the total phosphorus (TP), total nitrogen (TN), and chemical oxygen demand (COD) removal were about 97%, 94 %, and 95 %, respectively, after 90 days of operation under optimal conditions. According to the findings, under aerobic/anoxic circumstances, denitrifying phosphate accumulating organisms (DNPAOs) play a significant role in nitrate reduction and phosphorus uptake. These findings showed that in the present system, degrading bacteria, denitrifying bacteria, phosphate accumulating organisms (PAOs), and DNPAOs were enriched at the optimal time for a stable operation cycle in the SBBR system, which could primarily denitrify substances due to a lack of organic carbon. Because they can cure nitrate/nitrite and phosphate using the same carbon sources, DNPAOs can help with organic carbon competition. Finally, electrolysis based on an electrochemical method was used to post-treat residual phosphate and nitrogen ions in effluent at the end of the aerobic/anoxic period, and results showed that residual phosphate and nitrogen ions were remarkably removed in the first minutes of the electrolysis process, with contents of TP, NO2––N, and NO3––N reaching 0.78, 0.61, and 0.18 mg/l, respectively, indicating electrochemical reaction was an effective method of