Critical flux determination by the flux-step method in a submerged membrane bioreactor

Le‐Clech, Pierre; Jefferson, Bruce; Chang, Ih-Seop; Judd, Simon

doi:10.1016/j.memsci.2003.07.021

Cited by 459 publications

(230 citation statements)

References 19 publications

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“…In the activated sludge filtration, like in an MBR, no such CF in strict form exists (Le Clech et al, 2003). The CF is slightly different than from the one mentioned earlier (Field et al, 1995 (Field & Pearce, 2011).…”

Section: Critical Flux Conceptmentioning

confidence: 69%

“…(Le Clech et al, 2003;van der Marel et al, 2009; Fluxstepping is preferred since the control over flux is easy. Several methods have been proposed by different authors, such as the flux-step method (Le Clech et al, 2003) and the improved flux-step method (van der Marel et al, 2009). The latter also provides the long-term fouling rate using the term of critical flux for irreversibility (JCir).…”

Section: Critical Flux Conceptmentioning

confidence: 99%

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Membrane bioreactor for domestic wastewater treatment: principles, challanges and future research directions

Bilad

2017

IJOST

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Membrane bioreactors (MBRs) have recently become widely accepted as an advanced technology for treatment of domestic and industrial wastewaters. The objective of this review is to provide overview on MBR technology for wastewater treatment application. It includes discussions on the fundamental, core problems (membrane fouling), recent effective development approach (dynamic filtration systems) and future research direction of MBRs. Since MBRs integrate a conventional activated sludge process with membrane filtration, and both fundamental aspects are discussed first. Later, a comprehensive discussion about membrane fouling, the main problems in MBR, is provided, including fouling control strategies. The discussion on the MBR membranes and relation between membrane properties and MBR performance is also provided. This review also includes one of the most promising MBR technologies that specifically design to manage membrane fouling: dynamic filtration systems. Lastly, insight into an approach to address MBRs challenges and recent research and developments are provided.

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Section: Critical Flux Conceptmentioning

confidence: 69%

Section: Critical Flux Conceptmentioning

confidence: 99%

Membrane bioreactor for domestic wastewater treatment: principles, challanges and future research directions

Bilad

2017

IJOST

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“…To allow parallel operation, a multichannel peristaltic pump (Watson Marlow) was used. The critical flux (CF) was determined using a flux step method [6]. For long-term filtration, a fixed sub-critical flux was selected to allow for stable filtration over an extended period of time.…”

Section: Experimental Methodsmentioning

confidence: 99%

Role of Surface Pores on Fouling of Polyvinylidene Fluoride Membranes in Submerged Membrane Bioreactors

Bilad

Druyts

Vankelecom

2017

IOP Conf. Ser.: Mater. Sci. Eng.

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Abstract. In this study, the roles of surface pores on membrane fouling was investigated using three membranes in two lab-scale membrane bioreactors. Characterization of the pristine membranes revealed that increasing polymer concentration decreases pore sizes and porosity. Critical flux was found to decrease with decreasing pore sizes. The finding was consistent for both MBRs. The results of the long-term filtration were in agreement with the flux-stepping test. The fouling layer was easily removed and only a few small particles remained as were observed with scanning electron microscopy. Surface pore sizes and porosity declined for all cleaned membranes, indicating permanent pore blocking, and the effect was higher for membranes with larger pore size. IntroductionMembrane bioreactors (MBRs) improve the conventional activated sludge process (CASP) by replacing the settling tank with a membrane separation. Implementation of MBRs offers advantages, such as reduced plant footprint, lower sludge production, increased process control and improved effluent quality leading to a higher economical value of the effluent. Applications of MBRs gains favorability due to a more stringent effluent standard and the need of effluent reuse. However, the attempts to further decrease operating costs are still being developed, mainly acting on reducing fouling and so increasing process efficiency [1,2].Membrane fouling is the main drawback of MBR operation. It diminishes permeance reflected by an increase in the transmembrane pressure (TMP) when operating under constant flux or a decrease in fluxes when operating under constant TMP. To control fouling, three main approaches are generally followed: exploiting hydrodynamic conditions, improving favourable sludge properties and improving membrane properties. Fouling cannot be completely eliminated, so after a certain period of filtration (weeks, months) extensive cleaning of the membranes is still required and accumulation of permanent fouling will eventually lead to membrane replacement [3,4]. In this study, the effects surface pores of polyvinylidene fluoride (PVDF) membranes on the filtration performance and membrane fouling are investigated. The filterability was evaluated using critical flux methods and long-term filtration.

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“…There was no significant difference in TMP changes between virgin (first operating period) and non-virgin (second operating period) membrane. In general, chemical cleaning is more effective than physical cleaning to recover flux in membrane system [37]. The chemical and physical cleaning were conducted together and original state of membrane was almost restored.…”

Section: Membrane Foulingmentioning

confidence: 99%

Performance and Fouling in Pre-Denitrification Membrane Bioreactors Treating High-Strength Wastewater from Food Waste Disposers

Lee

Kim

et al. 2017

Water

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Abstract:The study investigated the performance of the pre-denitrification membrane bioreactor (MBR) process to treat high-strength wastewater generated from food waste disposals. Extracellular polymeric substances (EPS) as membrane foulant and microbial community profiles were analyzed under different hydraulic retention time (HRT) operation conditions. The pre-denitrification MBR was effective for treating food wastewater with high chemical oxygen demand (COD)/N resulting in high total nitrogen (TN) removal efficiency. The operational data showed that effluent qualities in terms of COD, TN, and TP improved with longer HRT. However, membrane fouling potential as shown by specific membrane fouling rate and specific resistance to filtration (SRF) increased as HRT increased. The longer HRT conditions or lower influent loading led to higher levels of bound EPS while HRT did not show large effects on the level of soluble microbial products (SMP). The restriction fragment length polymorphism (RFLP) analysis showed similar microbial banding patterns from the sludges generated under different HRT conditions, indicating that HRT had minimal effects on the composition of microbial communities in the system. All these results suggest that the MBR with pre-denitrification is a feasible option for treating high-strength food wastewater and that different HRT conditions could affect the operational performance and the fouling rate, which is governed via changes in microbial responses through EPS in the system.

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Critical flux determination by the flux-step method in a submerged membrane bioreactor

Cited by 459 publications

References 19 publications

Membrane bioreactor for domestic wastewater treatment: principles, challanges and future research directions

Membrane bioreactor for domestic wastewater treatment: principles, challanges and future research directions

Role of Surface Pores on Fouling of Polyvinylidene Fluoride Membranes in Submerged Membrane Bioreactors

Performance and Fouling in Pre-Denitrification Membrane Bioreactors Treating High-Strength Wastewater from Food Waste Disposers

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