Investigation and optimization of the SND–SBR system for organic matter and ammonium nitrogen removal using the central composite design

Abstract

Wastewater containing ammonia nitrogen compounds is considered as a harmful material to environment due to eutrophication and toxicity effects; hence, finding practical methods for treating this type of wastewater seems necessary. In this study, performance of two sequencing batch reactors have been assessed for simultaneous nitrification and denitrification in treating synthesized wastewater containing ammonium nitrogen, using leachate obtained from cow dung as the biomass. The leachate obtained from cow dung as the source of bio‐sludge added to the reactors. Experiments were designed according to central composition design and response surface methodology with four operating variables including pH (6, 7.5, 9), cycle time (CT) (4, 12, 20 h), normalCnormalOnormalD/normalNnormalH4+−normalN ratio (5, 10, 15) and carbon source (Sodium acetate: normalSnormalBnormalRnormalS, Glucose: normalSnormalBnormalRnormalG). According to statistical analysis, experimental responses were in acceptable agreement with model predictions. CT was the most important operating variable in chemical oxygen demand (COD) and normalNnormalH4+−normalN removal. The maximum percentage of ammonium nitrogen removal was attained at pH 7.5 and CT 21.5 h. The optimum conditions were composed of pH 7.67, CT 19.15 h, normalCnormalOnormalD/normalNnormalH4+−normalN 10.95 and sodium acetate as carbon source, while COD, normalNnormalH4+−normalN and total nitrogen removals were 94.96%, 94.93% and 93.60%, respectively. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 1638–1646, 2018

Research progress of novel bio-denitrification technology in deep wastewater treatment

“…These microenvironments support the coexistence of aerobic and hypoxic metabolic activities ( Layer et al, 2020 ). This technology allows nitrification and denitrification reactions to occur in the same spatial domain, significantly reducing the required reactor volume ( Third et al, 2005 ; Masoudi et al, 2018 ). Additionally, SND imposes minimal demands for aeration and organic carbon, resulting in a reduction of approximately 30% in sludge production compared to traditional bio-denitrification processes ( Ma et al, 2017 ; Zhao et al, 2017 ).…”

Simultaneous Removal of Organic Matter and Nutrients from High Strength Organic Wastewater Using Sequencing Batch Reactor (SBR)

“…A study by Chen et al, 2018 reported that as the C/N ratio decreases, nitrogen removal is also reduced and the morphology of aerobic granular sludge gets worsened; in order to restore it, the C/N ratio must be increased from 100/10 to 100/5 [43]. As NH 3 -N reduction efficiency was higher than 90% in R1 and R2, it could be established that the lack of nitrogen removal was mainly because of inadequate denitrification when the organics were not enough for denitrifiers along with the nitrate and nitrite accumulation [44,45]. For low strength wastewater, with C:N:P of 100:10:2 (C/N = 10, C/P = 50), 90.7% removal of nitrogen in 6 h cycle time was reported [22].…”

“…However, a cycle time of 3 h, which is the lowest among the already reported studies, also proves to be sufficient for high COD, NH 3 -N, and PO 4 3− P removal at the same ratio (Figure 3b). [15,19,[23][24][25]28,35,37,44,[53][54][55][56]; (B) [6,22,26,28 30,34,36,37,44,45,53]; (C) [19,[22][23][24]30,35,37,54].…”

Restaurant wastewater treatment with a two-chamber septic tank and a sequencing batch reactor

“…The stabilization phase (idle) and aerobic reaction time, in addition to microorganism, aeration, and decomposition factors, influence COD removal. The longer the HRT, the longer the stabilization and aerobic reaction [16]. However, COD began to be removed from the filling stage because the wastewater at this point contained high amount of organic matter.…”