Optimization Removal of COD and Nitrogen at Different Hydraulic Retention Times in Biocord-Integrated Fixed-Film Activated Sludge Syste

Abstract

Although conventional activated sludge has been demonstrated to be a feasible approach for extracting nitrogenous chemicals and organic pollutants from wastewater, it still has a number of drawbacks. In this research, a pilot-scale biocord-integrated fixed-film activated sludge (Biocord-IFAS) reactor fed with actual domestic wastewater was operated to examine the effect of varying hydraulic retention time (HRT) on the COD and nitrogen removal. The type of material employed in this study is fibrous polypropylene (biocord), which is a major difference. The contribution of the Biocord-IFAS to COD removal efficiency reached 94.2% at HRT of 8 h and gradually decreased to 82.9% when HRT was reduced to 4 h. During the investigation period, a slight decrease in nitrification was found at a shorter HRT. The NH4+-N removal efficiencies at HRTs of 10, 8, 6, and 4 h were 97.8%, 98.7%, 97.1%, and 96.3%, respectively. The average effluent nitrate concentration was 5.3 mg/L with HRTs from 10 to 6 h, but over 30 mg/L with an HRT of 4 h. The SEM analysis results show that microorganisms have formed on the biocord surface. The results of this research have demonstrated the potential application of IFAS reactors in bioremediation procedures employing biocord material with great processing efficiency.

Assessment of Chemical Oxygen Demand Removal Efficiency and Microbial Dynamics during Aerobically Degradation of Wastewater in Activated Sludge

“…Additionally, COD elimination declined markedly to just 4% by day 12 as the balanced microbial community degraded. This contrasts the stable 82.9% and 94.2% removal by using an integrated fixed-film configuration to maintain biomass (Thi Tuyet Nhi et al, 2022). Overall, the present work highlights the importance of sustained community structure, diversity, and functional redundancy in activated sludge for consistent biological COD treatment.…”

“…Prominently, the achievement of high COD reductions above 90% with technologies such as extended aeration and the addition of activated carbon medium, Biocord-IFAS, fourstage SBRs, chemical activation of dye sludge and biofilm processes like moving bed biofilm reactors (Jagaba, Kutty, Noor et al, 2022;Khalidi-Idrissi et al, 2023;Meena et al, 2022;Thi Tuyet Nhi et al, 2022). Many conventional activated sludge plants also realized removals in the 75-85% band.…”