The effects of operation conditions of carbon/nitrogen ratio and pH on nitrogen removal in intermittently aerated membrane bioreactor (IAMBR)

Abstract

In this study, the effect of chemical oxygen demand/nitrogen (COD/N) and pH on nitrification-dentrification was investigated by operating a sequencing batch reactor with the use of aeration duration control, coupled with a membrane bioreactor (MBR) system to improve the efficiency of nutrient removal. Among the COD/N ratios of 2, 4 and 6, the removal efficiencies of NH þ 4 , NO À 3 and NO À 2 in permeate, were the highest at 92.31, 80.69 and 93.63% respectively, at the COD/N ratio of 6. This ratio is an important factor to be considered for successful nitrogen removal. For pH values of 5.5, 7.6 and 9 there was a great difference in the removal of NH þ 4 , NO À 3 and NO À 2 with pH 7.6 were the highest at 92.31, 84.51 and 93.63%, respectively. This implies that a pH above 7.6 should be maintained for a nutrient removal efficiency of approximately 90%.

Effect of operational modes on nitrogen removal and nitrous oxide emission in the process of simultaneous nitrification and denitrification

“…For comparison, pH in the fully aerobic SND dropped from 7.58 to 7.21. It is reported that nutrient removal efficiency could be achieved approximately 90% at a pH above 7.6 [34]. This might be due to the fact of the activity of oxidoreductase is not inhibited under the condition, so higher nitrogen removal efficiency was observed in the anoxic-aerobic SND.…”

Characteristics of nitrous oxide (N2O) emission from intermittently aerated sequencing batch reactors (IASBRs) treating slaughterhouse wastewater at low temperature

“…Theoretically, the stoichiometric requirement for denitrification was 2.86 g COD/g N, considering the electron transmitting balance between the organic substrate and NO 3 − -N [33]. However, in practice, COD/N requirements are usually higher in conventional biological nitrogen removal processes.…”

Comparison of chloride effect between A2O and SBR processes treating domestic wastewater

“…Previous research has reported that high concentration of chloride can cause plasmolysis and loss of cell activity, which has significant effect on the biological wastewater treatment [4][5][6]. Although biological treatment is influenced by high levels of salt, biological nutrient removal (BNR) systems proved efficient to use [7,8]. Among these BNR technologies, anaerobic/anoxic/oxic (A 2 O) and sequencing batch reactor (SBR) processes are *Corresponding author.…”