Liquid filtration process water treatment

Wet oxidation is a process where organic contaminants in liquids or soils are extracted into an aqueous phase and reacted with an oxidant at high temperature (220-290°C) and pressures (100-250 bar) to promote rapid destruction. Laari et al. [67] evaluated the efficiency of wet oxidation for the treatment of TMP processing waters. The major objective of this research was to reduce the concentration of lipophilic wood extractives (LWE) and to treat concentrated residues from evaporation and membrane filtration by low-pressure catalytic wet oxidation. 

Cross-flow filtration is also referred to as tangential flow filtration or microfiltration, but all three terms refer to a process by which membranes are used to separate components in a liquid solution (or suspension) on the basis of their size. The development of robust membranes in polymeric and ceramic materials has provided a powerful new technology for bioseparations, which is already widespread in the process industries as well as for water treatment processes. 

Major constituent of paper, cardboards, and textiles is the cellulose. Some of the products of cellulose are cellophane, rayon fiber, nitrocellulose, water-soluble adhesives, and binders. Powdered cellulose is used as inactive fillers in tablets and as a thickener and stabilizer in processed foods. In the laboratories, cellulose is used in TLCs as a stationary phase, liquid filtration, as highly hydrophilic and absorbent sponges. These days cellulose insulation made from recycled paper is becoming popular as an environment-fi-iendly material. On treatment with boric acid cellulose can be used as a fire retardant. 

Treatment of contaminated liquids such as water, leachate, filtrate, groimdwater, storm water, surface water and industrial process waste water can be accomplished by several of SBP s technologies. Certain waste streams can be concentrated by the hyperfiltration units the permeate is clean water and the "ctMicentrate" contains the reduced volume of the pollutants. These concentrated contaminants can often be bioremediated, thus minimizing the waste stream. Other liquids may be treated directly, either by biological processes, or in the case of volatiles, air stripping with biotreatment of the pollutants in a gas phase bioreactor, or "biofilter". 

In the context of PFC removal, the improvement of PAC filtration is of particular interest since sorption of PFC on GAC may be inefficient (see Sect. 2.1). The filtration effect for PAC can be achieved by its immobilization on an appropriate supporting material such as polystyrene balls (Haberer process) [66, 67] or porous polyurethane cylinders [68]. A relatively new process in drinking water and pool water treatment is the combination of PAC with membranes (MFAJF). A full-scale application of PAC/UF for water treatment is the CRIST AL process (Combined Reactors /ntegrating a Separation by membranes and Treatment by Adsorption in Liquid), which is applied in Slovenia, France, and Switzerland for drinking water treatment [20]. Thereby, PAC is added to the raw water prior to filtration via UF-membranes operated in cross-flow mode [20]. The PAC-membrane process can be... 

Membrane filtration is a mechanical filtration technique, which uses an absolute barrier to the passage of particulate material as any technology currently available in water treatment. The term membrane covers a wide range of processes, including those used for gas/gas, gas/liquid, liquid/liquid, gas/solid, and liquid/solid separations. Membrane production is a large-scale operation. There are two basic types of filters depth filters and membrane filters. 

Many water treatment operators consider liquid chemicals easy to feed and handle. Chemical suppliers deliver the chemicals in sealed containers, and the feed and delivery systems are contained. Accurate feed is assured when using properly sized, calibrated, and maintained chemical metering pumps and control systems. Liquids also mix easily into the process water stream. Table 7-1 hsts some of the more common liquid chemicals used in water treatment. In addition to these, there are many liquid polyelectrolytes sometimes used in coagulation and filtration. They are not listed in the table because their properties vary depending on the specific product. 

The use of large amounts of water to remove residual chemical species and the final filtration process represent also drawbacks for such process despite its wide utilization. It is also worthy to note that for the liquid-phase functionalization the treatment temperature cannot be varied in a large range in order to avoid the thermal decomposition of the functionalized... 

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