Submerged membranes applications

Bouhabila, E.H., Ben Aim, R. and Buisson, H. (1998) Microfiltration of activated sludge using submerged membrane with air bubbling (application to wastewater treatment). Conference on Membranes in Drinking and Industrial Water Production, Amsterdam. 

Fane, Anthony G. "Submerged Membranes" in Advanced Membrane Technology and Applications, John Wiley Sons, Hoboken, New Jersey, 2008. 

Over the past decade, there has been an upsurge of interest in the use of gas bubbles to enhance membrane processes. The typical applications include two-phase flow filtration with tubular membranes and submerged membrane systems. A major stimulus for the latter has been the development of MBRs. 

Tire Zee Weed submerged-membrane technology and equipment for the project was provided by GE Water. Process Technologies. GE s Zee Weed membrane bioreactor systems combine ultiafiltration technology w ith biological treatment for municipal, commercial and industrial wastewater treatment and water reuse applications,... 

Figure 10.34b shows a vibrating submerged hollow fiber membrane system for filtration applications [81]. In this system, the submerged membrane is vibrated by a mechanical... 

Submerged membrane bioreactors are revolutionizing waste water treatment [108]. These units dramatically increase the capacity of waste water treatment ponds while simultaneously producing a higher quality water by using an ultrafiltration membrane to remove treated water from the mixed liquor suspended solids (MLSS) produced by biological treatment. Such process intensification is one of the hallmarks of applications where membrane processes have achieved commercial success (in addition to energy reduction and purification of labile compounds). 

Continuing advances in development of new membranes with better thermal, chemical, and improved transport properties have led to many new possible applications. Development of newer membrane modules and operating procedures in recent years has provided a key stimulus for the growth of the membrane industry such as submerged membrane filtration for treating municipal water. 

However, there were a few attempts to evaluate the operation costs of PMRs in terms of energy consumption. For example, Ryu et al (2005) performed an energy cost analysis of a PMR applied for removal of humic acids, dyes and 4-chlorophenol from water (Table 21.4). The pilot scale PMR was composed of a 500 dm reactor with MF submerged membranes (effective surface area of 8 m ) above which UV-A lamps were positioned (365 nm, 300 W). In the bottom of the reactor an air blower was mounted. The permeation was conducted by means of a suction pump. The PMR was found by the authors to be cost effective (9.65 kWh/m ) compared to other conventional processes. However, it was also noted that many terms including capital cost, membrane replacement and maintenance should be also considered to build a complete budget (Ryu et aL, 2005). Such an economic analysis of various membrane systems and applications was recently discussed by Calabrb and Basile (2011). 

Submerged (or immersed) membranes are now commonplace in advanced water and wastewater applications. However, this is a relatively recent development for example, the subject does not rate a mention in Membrane Handbook (Ho and Sirkar, 1992) and only has the briefest mention in Water Treatment Membrane Processes (Mallevialle et al., 1996). This chapter provides an overview of submerged membranes, from basic features to practical aspects and applications. We wiU start with the background to this development. 

In membrane processing the application of surface shear is required to control concentration polarization and fouling for high solids feeds or to assist cake removal for batch membrane filtration of low solids feeds. For submerged membranes the common practice is to use two-phase bubbly flow to induce surface shear. This section deals with the role of bubbles as well as other hydrodynamic aspects of submerged membranes. 

Low Solids Feed by Dead-end Filtration For applications such as water treatment the solids content is low and it is common to use submerged membranes in... 

Submerged membranes are applied to both water and wastewater treatment, and in both applications it is vital that damage to the membranes can be monitored. The issue is probably more important for drinking water where passage of pathogens (such as Cryptosporidium) into the final product water is a public health risk. Regulations are... 

Submerged membranes are now an established feature in the water industry for water treatment, water process pretreatment, and wastewater treatment. The following sections provide brief comments on these applications. 

A large membrane pack of this type will act like an artificial gill, permitting a swimmer to breathe like a fish and remain submerged for much longer periods of time than are possible with scuba equipment. Speculative fiction has man returning to live in the seas, and this type of application may make it possible. Their application in spacecraft is obvious as a part of a continuously recycled air support system. The oxygen permeability of silicone materials is just one example of the selective permeability of plastics. 

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