Effects of sludge retention time on oxic-settling-anoxic process performance: Biosolids reduction and dewatering properties

Abstract

Nghiem, L. D. (2016). Effects of sludge retention time on oxic-settlinganoxic process performance: biosolids reduction and dewatering properties. Bioresource Technology, 218 1187-1194.Effects of sludge retention time on oxic-settling-anoxic process performance: biosolids reduction and dewatering properties AbstractIn this study, the effect of sludge retention time (SRT) on oxic-settling-anoxic (OSA) process was determined using a sequencing batch reactor (SBR) attached to external aerobic/anoxic reactors. The SRT of the external reactors was varied from 10 to 40 d. Increasing SRT from 10 to 20 d enhanced volatile solids destruction in the external anoxic reactor as evidenced by the release of nutrients, however, increasing the SRT to 40 d did not enhance volatile solids destruction further. Relatively short SRT (10-20 d) favoured the conversion of destroyed solids into inert products. The application of an intermediate SRT (20 d AbstractIn this study, the effect of sludge retention time (SRT) on oxic-settling-anoxic (OSA) process was determined using a sequencing batch reactor (

Simultaneous sludge minimization, biological phosphorous removal and membrane fouling mitigation in a novel plant layout for MBR

“…The specific oxygen uptake rate (SOUR) slightly increased from Period 1 (30 mgO2 L -1 h -1 ) to Period 3 (31.7 mgO2 L -1 h -1 ), whereas it significantly arose in Period 4 to approximately 40 mgO2 L -1 h -1 . The SOUR increase was previously observed in OSA systems (Semblante et al, 2016b). The sharp increase of SOUR was likely related to the alternation of fasting/feasting conditions, which led the starved biomass to use more oxygen when it was returned to the mainstream aerobic reactor where a high substrate availability was ensured by the influent wastewater.…”

“…of sludge reduction was obtained in a SBR connected to an anaerobic side stream reactor operating under 12 h of HRT and 30 days of SRT (Semblante et al, 2016b). In another study carried out with ASSR-MBR systems, the maximum excess sludge reduction (55-58%) was achieved under 10-11 h of HRT in the anaerobic reactor (Saby et al, 2003;Ferrentino et al, 2016).…”

Fate of trace organic contaminants in oxic-settling-anoxic (OSA) process applied for biosolids reduction during wastewater treatment

“…The reactors used in this study were previously described (Semblante et al, 2016). Briefly, the OSA system consisted of a sequencing batch reactor, SBROSA (5 L), attached to external aerobic/anoxic (2 L) and anoxic reactors (2 L) ( Figure 1a).…”

“…Sludge reduction was determined as described in a previous study (Semblante et al, 2016). Briefly, sludge reduction was the difference in sludge yield of SBROSA and SBRcontrol:…”

“…Consequently, volatile solids are destroyed and converted into inert forms in the external anoxic reactor/s. Using real sewage as feed, recent studies have shown that OSA can reduce the sludge yield (mass of sludge produced/mass of substrate consumed) of sequencing batch reactors (SBRs) by more than 35% depending on factors such as influent characteristics, sludge interchange rate, and SRT (Semblante et al, 2015a; Semblante et al, 2016). Additionally, they have shown that OSA does not have any negative impact on wastewater treatment efficiency regarding basic water parameters such as chemical oxygen demand and sludge properties such as settleability (Coma et al, 2013;Semblante et al, 2015a).…”