The effect of sludge retention time and organic loading rate on performance and membrane fouling in membrane bioreactor

The membrane fouling behaviors and fouling mechanism of filamentous bulking sludge in membrane bioreactor (MBR) have been reported in recent studies. However, few studies have been conducted towards the causes and control of filamentous bulking sludge in MBR. In order to make clear the conditions of filamentous bacteria overgrowth in MBR, the impact of DO and organic loading rate on filamentous growth and its characteristics were investigated in this paper. The results showed that overgrowth of filamentous bacteria occurred under a relatively high substrate concentration (organic loading rate was 0.61 KgCOD/(KgMLSS•d), and DO was above 2 mg/L) in MBR. Nutrient removal effect can not be deteriorated under filamentous bulking sludge, with average 95, 57 and 92% removal efficiencies of COD, TN and TP respectively. The particle size of filamentous sludge was larger than that of normal sludge and the filamentous bacteria produced more SMP and EPS than floc forming bacteria.

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Anaerobic hybrid membrane bioreactor for treatment of synthetic leachate: Impact of organic loading rate and sludge fractions on membrane fouling

Waste Management ◽

10.1016/j.wasman.2020.04.031 ◽

2020 ◽

Vol 108 ◽

pp. 41-50 ◽

Cited By ~ 2

Author(s):

Isha Burman ◽

Alok Sinha

Keyword(s):

Membrane Fouling ◽

Membrane Bioreactor ◽

Loading Rate ◽

Hybrid Membrane ◽

Organic Loading Rate ◽

Organic Loading ◽

Synthetic Leachate

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Change of foulant concentration in an anaerobic membrane bioreactor

Water Science & Technology ◽

10.2166/wst.2020.296 ◽

2020 ◽

Author(s):

Susumu Hasegawa ◽

Genki Murakami ◽

Ryosuke Takagi ◽

Hideto Matsuyama

Keyword(s):

Liquid Chromatography ◽

Membrane Fouling ◽

Membrane Bioreactor ◽

Loading Rate ◽

Membrane Bioreactors ◽

Organic Loading Rate ◽

Organic Loading ◽

Excess Sludge ◽

Anaerobic Membrane Bioreactors ◽

High Rejection

Abstract Anaerobic membrane bioreactors (AnMBRs) have many advantages, such as producing methane gas for energy generation and little excess sludge. However, membrane fouling is a serious problem because the foulant, which causes the membrane to foul, may get rejected by the membrane and accumulate in the reactor, resulting in an acceleration of membrane fouling. However, there is no information related to a change in the foulant concentration in an AnMBR. Therefore, we examined the changes in the foulant concentration in the reactor, related to membrane fouling in an AnMBR. For the influent, reactor solution, and effluent, the concentration of each component of the foulant was analyzed by using a liquid chromatography-organic carbon detector (LC-OCD). It was found that fouling in the AnMBR was closely related to the components in the reactor, and the main foulant of the ultrafiltration (UF) membrane was biopolymers (BPs). BP accumulated in the reactor because of a high rejection by the UF membrane. However, once the BP accumulated in the reactor was biodegraded, the concentration of BP decreased with time even under a high organic loading rate of 1.9kg TOC/m3/day.

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