Flow rate impact on the performance of immobilized nanoFeCu for sewage treatment and its reusability

Ammonia pollution is a global issue, and it endangers human and aquatic life. The role of nanoFeCu in oxidizing ammonia has been identified, but its practicality and performance on the pilot scale are still unclear. This study was conducted to investigate immobilized nanoFeCu's performance in terms of ammonia, nitrate, nitrite, biological oxygen demand (BOD), chemical oxygen demand (COD), and total suspended solid (TSS) by using sewage as feed. The effect of sewage flow rate was studied to determine the optimum operating condition of a pilot-scale reactor. The reusability test was conducted to address sustainability concerns. The nanoFeCu was synthesized, immobilized in polymer clay, and placed into the reactor filled with sewage at a varied flow rate of from 210 to 1200 mL/min. Results showed that a higher sewage flow rate increased the ammonia removal rate within a shorter time but exhausted the immobilized nanoFeCu at a higher rate. Nitrate, nitrite, and TSS have a similar removal trend as ammonia. 800 mL/min was identified as the optimum flow rate with effluent ammonia concentration below 10 ppm in 9 h and maintained for 12 h. A reusability study showed that immobilized nanoFeCu could be reused for at least 10 successive cycles. The stability and performance of immobilized nanoFeCu suggested that it could be an alternative to treat sewage wastewater for real-life applications.