Biodegradation of the atenolol and nitrogen removal using the sequencing batch biofilm reactor

Biodegradation of 2-4-6 trichlorophenol by sequencing batch reactors (SBR) equipped with a rotating biological bed and operated in an anaerobic-aerobic condition

“…Due to the predominance of aerobic species in the activated sludge of municipal wastewater treatment plants (biolak process), to strengthen anaerobic species and enhance biofilm growth on media, in this study, separate anaerobic and aerobic bioreactors were used for biomass acclimation (Aghapour et al, 2013a;Aghapour et al, 2013b;Aghapour et al, 2015;Khorsandi et al, 2018;Khorsandi et al, 2020;Rezaei et al, 2022a;Rezaei et al, 2022b). To acclimate the biomass in each bioreactor, synthetic wastewater containing TCP with a concentration of 3.5 mg/L was used.…”

“…Therefore, this study will use a combination of anaerobic and aerobic processes for the biodegradation of TCP. In biological processes, the duration of the biomass acclimation period varies from a few days to Frontiers in Environmental Science frontiersin.org several months, depending on the type of compounds in the incoming wastewater (Mondal et al, 2011;Aghapour et al, 2013a;Aghapour et al, 2013b;Aghapour et al, 2015;Han et al, 2015;Barik & Gogate, 2018;Khorsandi et al, 2018;Khorsandi et al, 2020;Rezaei et al, 2022a;Rezaei et al, 2022b). In this study, the biomass in each bioreactor was acclimated to TCP after 30 days.…”

“…By increasing the concentration from 200 to 300 and 430 mg/L, due to the increased toxicity and inhibitory effect of TCP on the growth and metabolism of the biomass, the bioreactor efficiency decreased and gradually increased and reached a steady-state condition. It is related to the reinforcement of biological agents of wastewater treatment in terms of type and number created by increasing the biofilm with a rotating biological bed (Aghapour et al, 2013a;Aghapour et al, 2013b;Aghapour et al, 2015;Khorsandi et al, 2018;Khorsandi et al, 2020;Rezaei et al, 2022a;Rezaei et al, 2022b). Also, the bioreactor operation under sequential anaerobic and aerobic conditions has led to the growth of resistant biological species with a high potential for biological degradation of TCP (Huff, 2012).…”

“…The hydraulic retention time (HRT) of the bioreactor is considered an essential design and effective parameter in the construction costs of the treatment plant (Aghapour et al, 2013a;Aghapour et al, 2013b;Aghapour et al, 2015;Khorsandi et al, 2018;Khorsandi et al, 2020;Rezaei et al, 2022a;Rezaei et al, 2022b). In this study, HRT started from 30 h and was gradually reduced to 25, 20, 16, and 12 h after reaching steady-state conditions.…”

“…The mean removal efficiencies of TCP and TP in steady-state conditions and with an HRT of 30, 25, 20, 16, and 12 h are almost 100%, and for COD related to TCP were determined 95, 95, 95, 95, and 94%. Due to the high efficiency and ability of the bioreactor to biodegrade TCP by reducing the HRT, the removal efficiency of TCP and TP did not change much, and only the COD removal efficiency associated with TCP decreased and gradually increased after a few days and has reached a steady-state condition (Aghapour et al, 2013a;Aghapour et al, 2013b;Aghapour et al, 2015;Khorsandi et al, 2018;Khorsandi et al, 2020;Rezaei et al, 2022a;Rezaei et al, 2022b).…”