Water treatment patents

NOTE Application patents for the use of erythorbates in BW were instituted by Nalco, Betz, and Calgon. The fact that three water treatment patents were issued for essentially the same product application shows the ease of finding alternative application protocols within the industry. 

Displacement-purge forms the basis for most simulated continuous countercurrent systems (see hereafter) such as the UOP Sorbex processes. UOP has licensed close to one hundred Sorbex units for its family of processes Parex to separate p-xylene from C3 aromatics, Molex tor /i-paraffin from branched and cyclic hydrocarbons, Olex for olefins from paraffin, Sarex for fruc tose from dextrose plus polysaccharides, Cymex forp- or m-cymene from cymene isomers, and Cresex for p- or m-cresol from cresol isomers. Toray Industries Aromax process is another for the production of p-xylene [Otani, Chem. Eng., 80(9), 106-107, (1973)]. Illinois Water Treatment [Making Wave.s in Liquid Processing, Illinois Water Treatment Company, IWT Adsep System, Rockford, IL, 6(1), (1984)] and Mitsubishi [Ishikawa, Tanabe, and Usui, U.S. Patent 4,182,633 (1980)] have also commercialized displacement-purge processes for the separation of fructose from dextrose. 

Ford, D.L. Manning, F.S. Treatment of petroleum refinery wastewater. In Carbon Adsorption Handbook Cheremisinoff, P.N., Ellerbusch, F., Ed. Ann Arbor Science Ann Arbor, Ml, 1978. Patterson, J.W. Industrial Wastewater Treatment Technology, 2nd Ed. Butterworth Boston, 1985. Hutton, D.G. Robertaccio, F.L. Waste water treatment process. U.S. Patent 3,904,518, September 9, 1975. 

MiKIE is a mobile, modular biological water treatment technology used for the treatment of organic contaminants. The system was developed and patented by John D. Bogart and is commercially available from Bogart Environmental Services, Inc. According to the vendor, the MiKIE system has been in use for water decontamination on several sites for nearly 5 years. 

Many commercial companies, trade associations, and other organizations within the worldwide water treatment industry possess a wealth of in-house, technical problem-solving and research data. Also, they hold patents,... 

In spite of the potential of this promising technology, development of a practical water treatment system has not yet been successfully achieved. In the last decade, a large number of publications have appeared based on laboratory-scale studies with generally positive results for very diverse categories of toxic compoimds in water. However, technical development to pilot-scale level has not been successfully achieved although there are numerous patents approved worldwide. 

Figure 2 Estimated number of patents on titanium dioxide photocatalysis per year, categorized according to water treatment (empty triangles), air treatment (filled diamonds), self-cleaning surfaces (empty circles).

Figure 3 The distribution of patents between the three major categories (air treatment, water treatment, self-cleaning) on a cumulative basis.

SenGupta, A.K. and Prakash, P. Process for Selective Coagulant Recovery from Water Treatment Plant Sludge. United States Patent... 

In 1927, O.scar and Hudolf Adler of Czechoslovakia were granted a patent for the use of activated carbon for water dechlorination [4]. Their work seemed to rekindle interest in the application of carbon in water treatment in both Europe... 

Meng. X.G. et al.. Methods of preparing a surface-activated titanium dioxide product and of using same in water treatment processes, U.S. Patent 6 919 029, 2005, cited in [2110]. 

After the expiration of the UOP patent covering the rotary valve, there have been several modifications to the moving port technique by Amalgamated Sugar,l l Illinois Water Treatment,and Mitsubishi. Each manufacturer has its own proprietary approach for the establishment and control of the chromatographic pattern. 

Manufacturers. Gulligan has become an acknowledged leader in water treatment since the company was founded in 1936. First known for its water softeners, its research and development team has made advancements in water treatment that have resulted in its holding more than 200 patents worldwide. 

Vinylphosphonic acid is produced in Germany and used, initially by Hoechst, later by others to manufacture a hydrophilic poly(vinylphosphonic acid) prepared by free-radical polymerization in a solvent (70,71). Poly(vinylphosphonic acid) is mainly used for the treatment of aluminum photolithography plates before application of the photosensitive layer (72,73). The coating improves the developing and printing characteristics of the plate. Dental cement applications of cross-linked poly(vinylphosphonic acid) have also been studied (74). Vinylphosphonic acid copolymers with vinylsulfonic acid have been patented as scale inhibitors for water treatment (75). 

A combination of gravity settling and slow cyclonic action was first patented in 1983 and has since been available commercially. It is known as the hydrodynamic or gravity-and-vortex-induced separator and used for the excess storm water treatment or for the separation of grits and sands Irom... 

In 1994 Rhodia was granted a patent for the production of an Al/OHx/Cly poly-aluminiumchloride compound for water treatment. The production was, however, associated with the formation of an undesirable insoluble secondary product. Use of a 14 m semi-batch reactor did not allow separation, and the solution was to install a quick mixer which was Y-shaped and mixed the reactants under good... 

Examples of water treatment using the BDD anode extracted from the literature and patents are summarized in Table 2. It is revealed that... 

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