Particulate fouling studies with alumina dispersions in water were performed in rectangular, silicon microchannels having hydraulic diameters between 220 and 225 lm with Reynolds numbers of 17–41. Data show for the most part the absence of particle deposition within the microchannels. The primary reason for this is the relatively high wall shear stress at the microchannel walls of 2.3–3.5 Pa co...

Abstract Ballast fouling in railroad substructure is detrimental to railroad track effectiveness and its structural capacity. Ground penetrating radar (GPR) provides a rapid, effective and continuous approach to assess railroad substructure condition. However, unknown ballast dielectric constant and unclear interface between clean and fouled ballast limit the GPR assessment accuracy. In this st...

The thermodynamic interactions between membrane and sludge flocs in a submerged membrane bioreactor (MBR) were investigated. It was found that Lewis acid-base (AB) interaction predominated in the total interactions. The interaction energy composition of membrane-sludge flocs combination was quite similar to that of membrane-bovine serum albumin (BSA) combination, indicating the critical role of...

This paper deals with time-optimal operation of batch diafiltration processes in the presence of membrane fouling. Fouling causes a decrease in membrane area and, hence, an increase in processing time. In this work we study a time-optimal operation with several fouling models available in literature. Pontryagin’s minimum principle is applied to characterize the structure of the optimal operatio...

Despite technological advances of several desalination processes such as reverse osmosis, still considerable proportion of installed units are thermally driven processes which their efficiency can severely be reduced by the formation of fouling deposits on heat transfer surfaces. For many years, it has been practical strategy to avoid fouling rather than facing it. Some of these strategies are ...

Two parallel anaerobic membrane bioreactors (MBRs), integrated with or without ultrasound equipment for online membrane fouling control (US-AnMBR, or AnMBR) were established to digest waste activated sludge (WAS). The characteristics of bound extracellular polymeric substances (EPS) and bacterial communities in the systems were investigated for further understanding of the membrane fouling mech...

Numerous membrane fouling studies have been conducted to predict and prevent membrane fouling. It was only recently that a new parameter, TEP, was introduced in this research. The deposition of TEP on reverse osmosis (RO) membranes has already been imaged, correlations between ultrafiltration (UF) fouling and TEP concentrations have been reported. Furthermore, TEP deposition takes place in an e...

Effects of wastewater and mixed liquor characteristics on membrane fouling in both a submerged anaerobic membrane bioreactor and a thermophilic submerged aerobic membrane bioreactor were studied with four types of industrial wastewaters. Significant differences in particle size distribution, colloidal content, the protein to polysaccharide ratio, and soluble compounds molecular weight distribut...

Aerobic granular sludge was cultivated adopting internal-circulate sequencing batch airlift reactor. The contradistinctive experiment about short-term membrane fouling between aerobic granular sludge system and activated sludge system were investigated. The membrane foulants was also characterized by Fourier transform infrared (FTIR) spectroscopy technique. The results showed that the aerobic g...

A reliable dynamic simulator (based on a sound process model) is highly desirable for optimizing the performance of individual membrane modules and of entire desalination plants. This paper reports on progress toward development of a comprehensive model of the complicated physical-chemical processes occurring in spiral wound membrane (SWM) modules, that accounts for the...