Pretreatment

As membranes were considered compatible with non-biological debris, the necessities of fine screens to remove debris were often underestimated in very early days. It was partially true when tubular membranes were the major membrane option, but it turned out to be not true soon after immersed (or submerged) membranes were introduced commercially in early 1990’s. […]

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Reference

Abdullah, S.; B√©rub√©, P. (2013) Assessing the effects of sodium hypochlorite exposure on the characteristics of PVDF based membranes, Wat. Res. 47, 5392-5399. Ayala, D.F.; Ferre, V.; Judd, S.J. (2011) Membrane life estimation in full-scale immersed membrane bioreactors, J. Membrane Sci., 378, 95-100. ASCE (1991). ASCE Standard: Measurement of Oxygen Transfer in Clean Water, ISBN […]

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Petroleum refinery wastewater treatment

Recently, more and more refineries are adopting MBR for wastewater treatment, but not many reports with full-scale data are available in public domain. However, based on the available anecdotal information on full-scale MBR along with lab-scale data, it is apparent that removal efficiencies of hydrocarbons, suspended solids, BOD/COD are very satisfactory while concerns are still […]

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Pretreatment of oily wastewater

American Petroleum Institute (API) separator API separators are commonly used to remove floating oil and precipitating solids simultaneously from water. Its desing is very similar to the rectangular clarifiers used for non-oily wastewater, but the design and operation of skimmer and scrapper are optimized for removing oily wastewater. API separators are designed to capture oil […]

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Trace organic removal by MBR

Removal efficiency As a result of the use of various chemicals for pharmaceutical or personal care purposes, any municipal wastewater stream carries many of the following chemicals that can potentially harm environment by affecting the matabolism of aquatic lives. Steroidal hormons – Androstenedione, Androsterone, Etiocholanolone, Dihydrotestosterone, Testosterone, 17b-estradiol, Estriol, Estrone Xenoestrogens -Bisphenol A, Propylparaben Pharmaceutical […]

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Trace organic removal mechanism

Removal mechanism In recent decades, concerns over trace organics such as pesticides, pharmaceuticals, personal care products, steroidal hormones have been growing. Many of those trace organics are suspected as endocrine disruptors on aquatic organisms and eventually on human (Yoon, 2007). Though exact removal mechanism by activated sludge is still under investigation, following mechanisms are plausible. […]

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Factors affecting membrane longevity

The longevity of immersed membrane is highly affected by the operating and maintaining condition as follow. ¬∑¬†¬†¬†¬†¬†Installation technique/skill¬†‚Äď In addition to the membrane‚Äôs build quality, how it is installed is another factor affecting membrane longevity. As discussed¬†here, uneven air flow rates among modules and cassettes can cause physical damages on membranes eventually. It is crucial […]

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