Recycling rainwater by submerged gravity-driven membrane (GDM) reactors: Effect of hydraulic retention time and periodic backwash

Sequencing Batch Integrated Fixed-Film Activated Sludge Membrane Process for Treatment of Tapioca Processing Wastewater

“…Even though biofouling is utilized to enhance biological treatment, the membrane may still need cleaning after being used for an extended period. This approach has been suggested in maintaining the stability of other gravity-driven filtration systems [9,12]. Thus, the membrane clogging can be cleaned with a combination of physical and chemical cleaning for extensive foulant removals [30,31].…”

“…The treated wastewater also experiences additional treatment by the biofilm leading to enhanced permeate quality [8][9][10]. Several reports emphasized that the transmembrane pressure (hereafter termed as hydrostatic pressure driven by gravity) affected membrane permeability and is thus considered as an essential parameter [11,12].…”

Biocarriers facilitated gravity-driven membrane (GDM) reactor for wastewater reclamation: Effect of intermittent aeration cycle

“…Recently, gravity-driven membrane (GDM) filtration have received great attention as a decentralized process in treating surface water, rainwater, greywater, and sewage water (Cecconet et al 2019, Pronk et al 2019, Tang et al 2016, Wu et al 2019. The advantages of the GDM process include that (1) it can produce superior treated water due to high membrane separation efficiency; (2) it is an economic process due to its lower capital cost (no permeate suction pump) and operation cost (without requiring physical and chemical cleaning) compared to other membrane processes such as membrane bioreactors (MBRs).…”

“…Previous studies have shown that the GDM systems could potentially treat greywater/municipal wastewater, but with a relatively low permeability (30-70 L/m 2 h/bar), which is dependent on the wastewater quality such as organic concentrations (Ding et al 2016, Ding et al 2017a, Ding et al 2017b, Jabornig and Podmirseg 2015, Wang et al 2017). In addition, the GDM systems could not fully remove dissolved organic substances, such as humic substances, building blocks, and low molecular weight substances (Ding et al 2018a, Wu et al 2019.…”

Novel housing designs for nanofiltration and ultrafiltration gravity-driven recycled membrane-based systems

“…For all of these systems membrane fouling remains a core issue, although several fouling reduction techniques have been proposed, including membrane surface relaxation [11,17,25,26] and periodic application of shear stress (e.g. flushing [11,17,25] and backwashing [27]).…”