Effect of hydraulic residence time and inlet flow distribution ratio on the pollutant removal of low‐temperature municipal wastewater in multistage AO process

Abstract

Low temperature environment was one of the difficulties in sewage treatment. In this study, the removal efficiency of multistage AO process was analysed under different hydraulic residence time (12 h, 8 h and 6 h) and inlet flow distribution ratio(5 : 4 : 4, 3 : 2 : 1 and 25 : 15 : 6), the rules of pollutant migration and transformation were compared and analysed under different control parameters. The results show that enhanced nitrogen removal and optimised organics utilisation were obtained simultaneously in the feeding process with hydraulic retention time of 8 h as well as influent distribution ratio of 3 : 2 : 1. HRT and inlet flow distribution ratio affect nitrogen load and organic matter distribution in each stage of the multistage AO system, the removal efficiency of ammonia nitrogen in each stage of the system was more than 80% under optimal conditions, the total nitrogen removal rate was more than 80%, among which the synchronous nitrification and denitrification account for 29.50%.

Cationic lignin polymers as flocculants for municipal wastewater

“…Municipal wastewater is highly variable in composition and contains various organic and inorganic compounds (Ittisupornrat et al, 2015; Wang et al, 2020). It often contains high concentrations of phosphorous (4–15 mg/L) and nitrogen (12–50 mg/L), as well as varying concentrations of organic compounds (COD of 250–1000 mg/L) (Gupta, 2016).…”

Application of an Anaerobic–Anoxic–Oxic–Oxic (AAO/O) Model to the Treatment of Real Domestic Wastewater

“…e constituents of wastewater originating from households consist of nitrogen, phosphorus, and broad groups of organic matters [7]. Common technologies for the treatment of this type of wastewater are anoxic-oxic (AO) [8,9], AAO [10][11][12], University of Cape Town (UCT) [13,14], the sequencing batch reactor (SBR) [15,16], and membrane bioreactor (MBR) [13,17]. When applied to domestic wastewater, they have shown relatively high performance towards several bulk parameters, including COD, TN, TP, and TSS [8,15,16].…”

“…Common technologies for the treatment of this type of wastewater are anoxic-oxic (AO) [8,9], AAO [10][11][12], University of Cape Town (UCT) [13,14], the sequencing batch reactor (SBR) [15,16], and membrane bioreactor (MBR) [13,17]. When applied to domestic wastewater, they have shown relatively high performance towards several bulk parameters, including COD, TN, TP, and TSS [8,15,16]. Many prevalent technologies based on this combination have been developed.…”