Biofouling layer maintains low hydraulic resistances and high ammonia removal in the UF process operated at low flux

Shao, Senlin; Li, Yueqi; Jin, Tianci; Liu, Wushuang; Shi, Danting; Wang, Jun; Wang, Yi; Jiang, Yu; Li, Jiangyun; Li, Hui

doi:10.1016/j.memsci.2019.117612

Cited by 21 publications

(9 citation statements)

References 53 publications

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“…Fouling can cause severe flux losses that need to be restored by physical/chemical cleaning. Fouling of NF membranes is often associated with the deposition of organic substances and the formation of biofilm on membrane surfaces, − which can be greatly influenced by foulant–membrane interactions and hydrodynamic conditions near the membrane surface. , A crumpled membrane surface can affect both foulant–membrane interactions and hydrodynamic conditions, thus, showing significant impacts on membrane fouling.…”

Section: Critical Analysis Of Fouling Propensities Of Crumpled Nf Mem...mentioning

confidence: 99%

Nanofiltration Membranes with Crumpled Polyamide Films: A Critical Review on Mechanisms, Performances, and Environmental Applications

Shao

Zeng

et al. 2022

Environ. Sci. Technol.

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135

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Nanofiltration (NF) membranes have been widely applied in many important environmental applications, including water softening, surface/groundwater purification, wastewater treatment, and water reuse. In recent years, a new class of piperazine (PIP)-based NF membranes featuring a crumpled polyamide layer has received considerable attention because of their great potential for achieving dramatic improvements in membrane separation performance. Since the report of novel crumpled Turing structures that exhibited an order of magnitude enhancement in water permeance (Science2018360518521), the number of published research papers on this emerging topic has grown exponentially to approximately 200. In this critical review, we provide a systematic framework to classify the crumpled NF morphologies. The fundamental mechanisms and fabrication methods involved in the formation of these crumpled morphologies are summarized. We then discuss the transport of water and solutes in crumpled NF membranes and how these transport phenomena could simultaneously improve membrane water permeance, selectivity, and antifouling performance. The environmental applications of these emerging NF membranes are highlighted, and future research opportunities/needs are identified. The fundamental insights in this review provide critical guidance on the further development of high-performance NF membranes tailored for a wide range of environmental applications.

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Section: Critical Analysis Of Fouling Propensities Of Crumpled Nf Mem...mentioning

confidence: 99%

Nanofiltration Membranes with Crumpled Polyamide Films: A Critical Review on Mechanisms, Performances, and Environmental Applications

Shao

Zeng

et al. 2022

Environ. Sci. Technol.

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135

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“…In recent literature related to gravity-driven MBRs, researchers found that the fouling resistances remained at low levels over several months when operated at ultralow fluxes of <5 L·m –2 ·h –1 (mostly in the range of 1–2 L·m –2 ·h –1 ), − even without intensive physical cleaning . They attributed the low fouling to the activities of microorganisms in cake layers, which leads to loose cake layers with low hydraulic resistances. − Inspired by these studies, we hypothesize that the fouling of MBR NF would also be very slow at an ultralow flux (i.e., ULF MBR NF ), which would in turn enable a more sustainable single-step wastewater reuse.…”

Section: Introductionmentioning

confidence: 88%

Nanofiltration-Based Membrane Bioreactor Operated under an Ultralow Flux: Fouling Behavior and Feasibility toward a Low-Carbon System for Municipal Wastewater Reuse

et al. 2023

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Compared to a conventional membrane bioreactor (MBR) with a porous microfiltration (MF) membrane (MBRMF), a nanofiltration (NF)-based MBR (MBRNF) shows highly attractive features such as high permeate water quality. However, the practical applications of MBRNF are often hindered by the high driven pressures and severe membrane fouling. To address these two critical issues, this study investigated the feasibility of operating MBRNF at an ultralow flux (ULF, e.g., <5 L·m–2·h–1) toward the reuse of municipal wastewater in a single step. We operated the ULF MBRNF at a flux of 2 L·m–2·h–1 and benchmarked its performance against a conventional system using a MBRMF followed by a subsequent NF treatment (MBRMF + NF, both at a constant flux of 20 L·m–2·h–1). The results show that the ULF MBRNF achieved substantial removal of most pollutants, with low negative impacts of ultralow fluxes on pollutant rejections. Besides, the ultralow-flux operation led to a very low fouling rate (0.18 kPa·d–1). More importantly, the ULF MBRNF reduced carbon emissions by 45.2% compared with the MBRMF + NF, mainly due to less energy consumption by pumping. Our findings highlight the simplicity and great potential of ULF MBRNF for wastewater reuse.

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“…ImageJ 1.50i (NIH, USA) was used to threshold and binarize the raw images. The morphological parameters of cake layers, i.e., thickness ( d ) and roughness ( R a ), were computed with MATLAB (MathWorks, USA), according to the method provided in the previous studies. , …”

Section: Methodsmentioning

confidence: 99%

“…Moreover, although there are differences in the EPS and ATP content of UF systems with Mn(II) in the feed water at different fluxes (Figure S10a), the impact on total resistance is extremely limited because the organic matter fouling will always reach a resistance stabilization under the microbial decomposition effect and no longer increase. 37,42,46 These results suggest that microorganisms and EPS possibly have low impacts on the hydraulic resistance of the BioMnO x cake layers, and thus, BioMnO x generated by Mn(II) removal might cake layer; we assumed that the bright membrane surface in the OCT images was not covered by BioMnO x (a calculation case is shown in Figure S9). (c) Average diameter and volume fraction of BioMnO x in the cake layer (particle size distribution is shown in Figure S11; the density of BioMnO x was approximated as that of MnO 2 , i.e., ρ = 5.026 g cm −3 ).…”

Section: Biomno X Forms a Heterogeneous Cake Layer With Many Moundsmentioning

confidence: 99%

Exploring the Growth Pattern and Hydraulic Resistance of BioMnO_x Cake Layer under Different Fluxes in Ultrafiltration Processes

Wang,

Hu,

Zhou

et al. 2023

ACS EST Eng.

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Biogenic manganese oxides (BioMnOx) are known to self-catalyze Mn(II) oxidation and are unfavorable in conventional ultrafiltration (UF) processes for Mn(II)-containing water purification because they can accumulate on membrane surfaces and cause severe cake fouling. However, recent studies based on gravity-driven membrane (GDM) have found that the fouling resistance of the BioMnOx cake layer is surprisingly low under low flux conditions (several L m–2 h–1), but the underlying mechanism is not clear. Therefore, in this study, we investigated the formation and hydraulic resistances of the naturally formed BioMnOx cake layers at various fluxes (5, 10, 15, and 20 L m–2 h–1). The results showed that the BioMnOx could form a heterogeneous cake layer with many mounds, and these BioMnOx cake layers could remove nearly 100% of 2 mg L–1 Mn(II) after 34, 49, 55, and 64 days of dead-end filtration at fluxes of 5, 10, 15, and 20 L m–2 h–1, respectively. The hydraulic resistance of the BioMnOx cake layer rapidly increased at high fluxes of 10, 15, and 20 L m–2 h–1, while it remained very low (<5 × 1012 m–1) at a low flux of 5 L m–2 h–1. In-situ optical coherence tomography (OCT) observation revealed that at low flux, the BioMnOx mounds of the cake layer had a higher height–width ratio and lower coverage and thus more porous structures. We attributed this structure to the unique growth pattern of BioMnOx at low fluxes. Specifically, because the advection velocity of Mn(II) was low at low fluxes, new BioMnOx was mainly grown in the upper parts of the cake layer with enough time for Mn(II) diffusion and oxidation. Then, the upper parts depleted Mn(II), and consequently, the lower parts maintained a high porosity with few formations of BioMnOx at their confined pores.

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Biofouling layer maintains low hydraulic resistances and high ammonia removal in the UF process operated at low flux

Cited by 21 publications

References 53 publications

Nanofiltration Membranes with Crumpled Polyamide Films: A Critical Review on Mechanisms, Performances, and Environmental Applications

Nanofiltration Membranes with Crumpled Polyamide Films: A Critical Review on Mechanisms, Performances, and Environmental Applications

Nanofiltration-Based Membrane Bioreactor Operated under an Ultralow Flux: Fouling Behavior and Feasibility toward a Low-Carbon System for Municipal Wastewater Reuse

Exploring the Growth Pattern and Hydraulic Resistance of BioMnO_x Cake Layer under Different Fluxes in Ultrafiltration Processes

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Biofouling layer maintains low hydraulic resistances and high ammonia removal in the UF process operated at low flux

Cited by 21 publications

References 53 publications

Nanofiltration Membranes with Crumpled Polyamide Films: A Critical Review on Mechanisms, Performances, and Environmental Applications

Nanofiltration Membranes with Crumpled Polyamide Films: A Critical Review on Mechanisms, Performances, and Environmental Applications

Nanofiltration-Based Membrane Bioreactor Operated under an Ultralow Flux: Fouling Behavior and Feasibility toward a Low-Carbon System for Municipal Wastewater Reuse

Exploring the Growth Pattern and Hydraulic Resistance of BioMnOx Cake Layer under Different Fluxes in Ultrafiltration Processes

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Exploring the Growth Pattern and Hydraulic Resistance of BioMnO_x Cake Layer under Different Fluxes in Ultrafiltration Processes