Membrane-filtration system

The UF/MF market for municipal water treatment was worth 300 M in 2006 and is projected to double by 2014 [12]. This market is broadly divided into three categories (i) drinking/potable water, (ii) seawater RO/NF pre-treatment, and (iii) wastewater reuse [12—16]. Increasingly, UF/MF systems are being used for RO/NF pre-treatment 

1 Principle of operation Continuous cross-flow operation 

Low surface area and packing density (especially tubular membranes), large footprint and high power consumption - high cross-flow velocity required to prevent fouling results in increased head loss - makes cross-flow systems quite expensive (high Capex and Opex). They are, therefore, best suited for relatively small flows (up to 100 m /h) and special applications. Application of spiral-wound UF membranes is relatively new and limited to specific applications. 

UF and MF membranes alone do not remove total organic carbon (TOC) and tri-halomethane (THM) precursors [13]. Hence, pre-treatment entails addition of chemicals such as coagulants (FeCl3 or FeS04), alum or polyaluminium chloride to increase the size of suspended solids and colloidal particles and thus prevent or minimise colloidal, organic, and/or biological fouling. In the case of seawater desalination, membrane filtration has proven to be superior to multimedia filtration [14,15]. 

Constant flux vs. constant pressure and critical flux 

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Bubble Point Constancy. Although the exact relationship between the bubble point and the "pore size" of a microfiltration membrane is a matter of dispute (11, 12, 13, 14), nevertheless, it remains the quickest and most convenient means for demonstrating the continuing integrity of a membrane filtration system. It is consequently important that the bubble point be both reproducible (within a given range) and constant. It was, therefore, of considerable interest to discover that the bubble points of both conventional and poly(vinylidene fluoride) membranes increased with immersion time in deionized water whereas those of Tyrann-M/E and polyamide remained essentially constant (Figure 6). 

MVR Membrane Filtration System 1 Membrane Filtration System 2... 

The SBP membrane filtration system concentrates contaminants and reduces the volume of contaminated groundwater, surface water, storm water, landfill leachates, and industrial process water. This hyperfiltration system consists of stainless steel tubes coated with a multilayered membrane, which is formed in-place using proprietary chemicals. The membrane filtration system can be used with an SBP bioremediation system or another technology as part of a treatment train. 

SBP Technologies, Inc., is no longer in business. Although the membrane filtration system has been field demonstrated, the technology is not commercially available. 

The SBP slurry-phase bioremediation system can treat a wide range of organic contamination, especially wood-preserving wastes and solvents. A modified version can also treat polynuclear aromatic hydrocarbons (PAHs) such as creosote and coal tar pentachlorophenol (PCP) total petroleum hydrocarbons (TPH) and chlorinated aliphatics, such as trichloroethene (TCE). The technology can be combined with SBP s membrane filtration system to form a soil cleaning system to handle residuals and contaminated liquids. 

Mechanical forces can disturb the elaborate structure of the enzyme molecules to such a degree that de-activation can occur. The forces associated with flowing fluids, liquid films and interfaces can all cause de-activation. The rate of denaturation is a function both of intensity and of exposure time to the flow regime. Some enzymes show an ability to recover from such treatment. It should be noted that other enzymes are sensitive to shear stress and not to shear rate. This characteristic mechanical fragility of enzymes may impose limits on the fluid forces which can be tolerated in enzyme reactors. This applies when stirring is used to increase mass transfer rates of substrate, or in membrane filtration systems where increasing flux through a membrane can be accompanied by increased fluid shear at the surface of the membrane and within membrane pores. Another mechanical force, surface... 

FIGURE 8.43 Schematics of ultrasound membrane filtration systems, (a) Ultrasound bath and (b) ultrasound bom. 

Linpac, Recycle Paper Mill, Cowpens, South Carolina The first full-scale commercial pressurized ozone membrane filtration system was tested and installed in the Linpac recycle paper mill in Cowpens, South Carolina (Table 35.1) for TDS removal [50]. The mill produces linerboard and medium for the production of corrugated boxes from an OCC and mixed office waste (MOW) furnish. The mill has no liquid discharge stream. 

The principal idea of the pressurized ozone membrane filtration system is to convert total dissolved solids (TDS) to suspended solids, which are then more easily removed by membranes. The installed system consists of two processes. First, the... 

Hollow Fibers. The whole membrane-filtration system is exchanged, including membrane, support, flow channel, and high-pressure vessel. 

The development work with regard to application of DDS-RO( ) membrane filtration systems for treatment of effluents from the pulp and paper industry started in Norway in the beginning of 1972. 

A careful choice of cleaning solutions and procedures will extend the service life of the membrane. In many polymer membrane filtration systems. 

In all membrane filtration systems, the flow of liquid in the direction of the membrane and the retention of molecules at the surface of the membrane result in an increase in the concentration of these molecules at the surface of the membrane, an effect which is known as concentration polarization. The concentration of a substance increases with approach to the membrane and then behind the membrane, falls suddenly. With rising concentration at the surface of the membrane, a... 

Sopajaree, K., Qasim, S. A., Basak, S., and Rajeshwar, K., 1999a, Integrated flow-reactor membrane filtration system for heterogeneous photocatalysis. Part I. Experiments and modeling of a batch - recirculated photoreactor, J. App. Electrochem., 29(5) 533-539. 

The first contract was awarded to H20 s American suhsidiaiy. Membrane Systems Inc, The ow pressure membrane filtration system to be installed in the city of Oxnard, California, will recycle 6 million gallons of w astewater per day using membrane technologies. 

Presumptive positives are indicated by growth at 35 °C on Azide Dextrose broth, which also allows the organisms to be counted. The production of red colonies on Slanetz and Bartley s medium at 44 °C is also indicative of faecal streptococci, and this medium is frequently used in membrane filtration systems. These media may be in either the solid or liquid form, but solid media cannot be remelted once prepared. Azide is toxic and the manufacturer s advice for the preparation of these media should be followed. It may also become explosive in the presence of certain metals and should be disposed of carefully. Azide can be destroyed safely by treatment with excess sodium nitrite. 

Zouboulis I, Petala MD. Performance of VSEP vibratory membrane filtration system during the treatment of landfill leachates. Desalination 2008 222 165-175. 

The membrane filtration system shown in Figure 4.14 is a standard pressurised system (for a review of the various membrane filtration modules refer to Table 6.14). The PLC-controUed system is designed to treat 2700 m /h seawater or surface water and supply 2500 m /h filtered water to the RO desalination unit. The design recovery is greater than 90% based on a flux of 49 1/m /h at 25°C. Major components of the skid-mounted system are detailed below ... 

Several physicochemical methods and biological have been used to remove organic compounds in industrial effluents. Application of membrane filtration systems and adsorption processes in water treatment and effluent was used by a group of researchers. They developed a system for removal of phenol from an aqueous solution through a combined process of ultrafiltration and adsorption using kaohnite and montmorillonite. The adsorption experiments were performed in batch with 0.2 g of day and 100 mL of water contaminated in the range of variable concentration of the organic compound from 20 to 1000 mg L l, stirred for 12 h at 25°C. The results showed that the phenol removal efficiency was 80% and a maximum adsorption cap>adty equal to 40 mg (Lin et al., 2005). 

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