Water purification, decontamination

These processes are widely used for water purification, decontamination and water softening. Being a reversible process, the ion exchanger can be reused with desirable ions. 

Membrane filtration processes have been successfully applied to the field of environmental engineering for air pollution control,34 potable water purification,22-24 groundwater decontamination,35,36 industrial effluent treatment,37 hazardous leachate treatment,35,36 and site remediation,36 mainly because membrane filtration can remove heavy metals and organics. 

Recently, Wang100 introduced a membrane sequencing batch reactor (membrane-SBR) process for groundwater decontamination, water purification, and industrial effluent treatment. A membrane-SBR is similar to conventional SBR except that membrane filtration is used (instead of sedimentation) for the separation of mixed liquor suspended solids (MLSS) from the mixed liquor. 

DAF is used to remove suspended solids by decreasing their apparent density they then rise and float on the water surface. DAF is also used to remove soluble iron, VOCs, oils, and surface active agents by oxidation, air stripping, and surface adsorption. The flotation technology is becoming one of the most important technologies for groundwater decontamination, industrial effluent treatment, and water purification.58-6170... 

One of many sequencing batch reactor (SBR) processes developed by Wang, Kurylko, and Wang in 1994 (125) is a physicochemical sequencing batch reactor adsorptive bubble separation (SBR-ABS) process, which can be used for potable water purification, industrial water treatment, wastewater effluent treatment, and groundwater decontamination (126). There are various types of SBR-ABS systems (a) physicochemical SBR flotation, (b) physicochemical SBR fractionation, (c) biological SBR flotation (2,3,4). The physicochemical SBR flotation has been used successfully in full-scale operation in Europe (123). 

Water that is biologically contaminated is treated to remove bacteria, viruses, fungi, and parasites, by aeration, chlorination, ozone, ultraviolet radiation, or a combination of these methods. In the process of purification, decontamination by-products (DBPs) are produced. These are chemicals that are themselves toxic. DBPs are discussed in Section 8.9. 

Use Oxidizer, disinfectant, deodorizer, bleach, dye, tanning, radioactive decontamination of skin, reagent in analytical chemistry, medicine (antiseptic), manufacture of organic chemicals, air and water purification. 

Ethyl (2-chloroquinolyl-3-carbonyl)acetates 193 served as the starting compounds for the preparation of benzo[fi][l,8]naphthyridines 194-196 (1991FRP2642070, 1991FRP2642071) possessing high antibacterial activity against Gram-positive bacteria. These compounds are used for the treatment of skin staphylococcus infections and water purification and also as preservatives and decontaminants. 

Water treatment by granular activated carbon (GAC) filters is an effective technology for removing dissolved organic compounds. GAC filters are therefore applied for drinking water purification as well as decontamination of polluted water, as for example in pump and treat procedures. Unfortunately, removal capacity towards micropollutants is often reduced by natural organic matter (NOM) in water due to competitive interaction on GAC adsorption sites. 

Adsorbents for water and gas purification and for low level radioactive waste decontamination... 

Ollis DF (1993) Photoreactors for Purification and Decontamination of Air, in Ollis DF, Al-Ekabi H (eds.) Photocatalytic Purification and Treatment of Water and Air,... 

Electroremediation using electrical current is the final purification method discussed in this chapter. Here, an array of anodes are placed in the soil opposite an array of cathodes. When electric potential is apphed the following processes occur electrolysis of water in the soil, dissolution of polluting ions, migration of ions under the influence of the apphed potential field, and reduction or pH based precipitation at the cathode [68,69]. This technique, also known as electroreclamation or electrochemical soil decontamination, does not require a membrane however, improved electroremediation has been reported when ion-exchange membranes were incorporated into the system [70]. The function of the membrane is to retain OH ions produced at the cathode. Migration of these OH ions is prevented to avoid precipitation of the heavy metal ions in the sod. 

Veterinary pharmaceutical preparations Vitamin preparations Water decontamination or purification tablets Water, sterile for injections Zinc ointment... 

In the Aquafluor process [G4] developed by the General Electric Company, most of the plutonium and fission products in irradiated light-water reactor (LWR) fuel are separated from uranium by aqueous solvent extraction and anion exchange. Final uranium separation and purification is by conversion of impure uranyl nitrate to UFg, followed by removal of small amounts of PuF , NpFg, and other volatile fluorides by adsorption on beds of NaF and Mgp2 and a final fractional distillation. A plant to process 1 MT/day of irradiated low-enriched uranium fuel was built at Morris, Illinois, but was never used for irradiated fuel because of inability to maintain on-stream, continuous operation even in runs on unirradiated fuel. The difficulties at the Morris plant are considered more the fault of design details than inherent in the process. They are attributed to the attempt to carry out aqueous primary decontamination, denitration, fluorination, and distillation of intensely radioactive materials in a close-coupled, continuous process, without adequate surge capacity between the different steps and without sufficient spare, readily maintainable equipment [G5, R8]. 

From the viewpoint of water management the use of pesticides is a serious danger particularly when these substances are introduced into precipitation, surface, ground-, drainage or wastewaters. The cases of water contamination are often due to the neglect of essential safety measures during their application, purification and decontamination of machines used for their application and transport, and aerial application, particularly in unsuitable periods. 

Thome, 1. P., and Y. Van Daele. 1986. Chitosan as a tool for the purification of waters. Adsorption of polychlorinated biphenyls on chitosan and application to decontamination of polluted stream waters. In Proceedings of the International Conference on Chitin and Chitosan, 3rd Meeting, R. A. A. Muzzarelli, C. leuniaux, and G. W. Goodway, eds. pp. 551-54, New York Plenum Press. 

With respect to purification of the solution, i. e., decontamination of the solution by removal of the remaining fission and corrosion products, a solvent extraction process has been found satisfactory when water is the U333 solvent. 

With regard to long-lived radionuclides that show a low decontamination factor on the purification system (e. g. Cs in PWR primary coolant containing LiOH), the purification constant e also has to include the coolant losses via water exchange or leakages. On the other hand, fission products which form insoluble compounds or can be adsorbed onto non-dissolved corrosion product particulate matter may be removed from the coolant by plate-out onto the primary circuit surfaces. These and other parameters which are liable to affect the activity concentrations of the radionuclides in the primary coolant are the reason why a trustworthy calculation of source strengths can only be made using specific radionuclides such as fission product noble gas isotopes and iodine isotopes. 

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