Other Technologies

Other technologies that have been used under certain conditions include vacuum vaporization, hydrofracturing enhancement, electrochemical, and vitrification and electric heating techniques. 

Other dye-based technologies evaluated for optical data storage include photo-chromic dyes for rewritable systems and azo dyes for holographic data storage. Spirobenzothiopyran dyes such as (40) absorb in the red/near-IR in their colored form and are suitable for erasible optical data storage [34]. Dyes for holographic data storage, such as (41), are similar to those used in nonlinear optics [35] (see below). 

Infrared absorbers are used in security printing. Because of their durability and lower cost, phthalocyanines of type (33) tend be used [3,37], 

Infrared absorbers such as (33) and (43) [31] are being evaluated as solar screeners for car windscreens and windows to let in daylight but screen out the IR component which causes heating. Although phthalocyanines are renowned for their durability, it is proving difficult to meet the demanding requirements of ca. 10 years for cars and ca. 25 years for windows. 

There are other lithium accumulator technologies on the market. We shall discuss some of these in this section. Usually, they represent a particular case of one or other of the technologies mentioned above (Li-ion or Li-metal). 

This is a particular case of hthium-ion technology, in which the positive electrode is based on a metal phosphate (e.g. iron phosphate LiFeP04). The open-circuit voltage obtained per cell is approximately 3.3 V. The interest in this technology lies mainly in  

studies are still under way with a view to improving the durability of this technology. Indeed, increasing the temperature favors the dissolution of the iron, which further reduces the lifetime. 

This accumulator is a particular case of lithium-ion technology. It still uses two electrodes based on insertion compounds. The difference here is that the electrolyte is a solid polymer matrix in which the conductive liquid is captive. Therefore, it is possible to make batteries of all sorts of geometric shapes. 

Its main disadvantage (relating to the polymer electrolyte) is still the necessity of operating within a rednced temperature range (80-100 C) in order to obtain a maximum efficiency. 

High-surface-area three-dimensional electrodes (e.g., beds of granular activated carbon or carbon aerosols, graphite felts, and carbon fiber materials) have been used to adsorb organics from effluents [106, 107]. The potential of the carbon 

In all its forms, the surface of carbon has oxygenated functional groups and these have been used as the starting point for the covalent bonding of functional groups to the surface. Moreover, in order to enhance the coverage by the functional groups, it has become common to preoxidize the surface by either an anodic treatment or the use of a chemical oxidant. While the properties of these modified surfaces are more suited to sensors, such modifications have been explored for effluent treatment applications. For example, an oxidative treatment of carbon felt was found to enhance the rate of destruction of 4-nitrophenol by an electro-Fenton approach [109] while chemical modification with hydrazine [110] and an anthraquinone polymer [111] has also been reported to increase the efficiency of electro-Fenton treatment. 

Carbons modified with fluorine [112] and nitrogen [113,114] have also been extensively studied as catalysts in fuel cells leading to improvements in performance for both oxygen reduction and methanol oxidation. Both decrease in overpotentials and increase in lifetimes have been reported. The application of similar concepts to electrode materials for effluent/water treatment is likely to lead to electrodes with greater stability. A nitrogen-doped diamond-like carbon has been shown to be effective for generation of ozone in water and the resulting solution employed to sterilize water oiEscherichia coli [115]. 

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Bioremediation has many advantages over other technologies, both in cost and in effectively destroying or extracting the pollutant. An important issue is thus when to consider it, and a series of questions may lead to the appropriate answer (see Table 4). 

Polyurethane is pulverized to iacrease its bulk density, mixed with 30—80% of a thermoplastic mol ding material, gelled, and then granulated to give coated urethane foam particles 0.1 to 0.15 mm in size (48). The particle bulk density is three times that of the polyurethane, while the volume is 15% less. This material may be injection molded or extmsion molded into products (49). Other technologies for recycling polyurethanes have also been reported. 

Other Technologies. Ethylbenzene can be recovered from mixed Cg aromatics by superfractionation. This technology was first practiced by Cosden Oil Chemical Company in 1957 (Big Spring, Texas), based on a design developed jointly with The Badger Company. Several superfractionation... 

Other Technologies. As important as dehydrogenation of ethylbenzene is in the production of styrene, it suffers from two theoretical disadvantages it is endothermic and is limited by thermodynamic equiHbrium. The endothermicity requites heat input at high temperature, which is difficult. The thermodynamic limitation necessitates the separation of the unreacted ethylbenzene from styrene, which are close-boiling compounds. The obvious solution is to effect the reaction oxidatively ... 

A three-step process involving the oxidation of acetophenone, hydrogenation of the ketone to a-phenylethanol, and dehydration of the alcohol to styrene was practiced commercially by Union Carbide (59) until the early 1960s. Other technologies considered during the infancy of the styrene industry include side-chain chlorination of ethylbenzene followed by dehydrochlotination or followed by hydrolysis and dehydration. 

Heavy Metals Removal. Heavy metals should be removed prior to biological treatment or use of other technologies which generate sludges to avoid comingling metal sludges with other, nonhazardous sludges. 

The earliest method for manufacturiag carbon disulfide involved synthesis from the elements by reaction of sulfur and carbon as hardwood charcoal in externally heated retorts. Safety concerns, short Hves of the retorts, and low production capacities led to the development of an electric furnace process, also based on reaction of sulfur and charcoal. The commercial use of hydrocarbons as the source of carbon was developed in the 1950s, and it was still the predominate process worldwide in 1991. That route, using methane and sulfur as the feedstock, provides high capacity in an economical, continuous unit. Retort and electric furnace processes are stiU used in locations where methane is unavailable or where small plants are economically viable, for example in certain parts of Africa, China, India, Russia, Eastern Europe, South America, and the Middle East. Other technologies for synthesis of carbon disulfide have been advocated, but none has reached commercial significance. 

Symmetrical, long-chain cyanine dyes for laser appHcations provide output from 680 to 980 nm (76). Although these dyes were obtained through early screening procedures, infrared dyes for other technologies use similar stmetures. A long-chain indolenine-type cyanine dye, general stmeture as in dye (34), has been described as the sensitizer in optical disk memories (77). 

Electrical insulation is continually being improved. The motor manufacturers make use of this and other technological developments to put more power into smaller, lighter, more efficient packages. Modem insulating materials can withstand heat, moisture, and corrosive atmospheres, and new metals can withstand more mechanical punishment. Computer design techniques are also helpful. 

Hybrid systems of acrylics with other technologies have been reported. Aciylic and epoxy polymers can be coupled through the use of 2-methacryloloxyethyl phosphate. The phosphoric acid functionality reacts with epoxy and the methacrylate group copolymerizes with the acrylic backbone [ 145] (Scheme 14). 

Preference should be given to the membrane process due to its less polluting characteristics over other technologies. In addition, the scrubbing of chlorine from tail gases to produce hypochlorite is highly recommended. 

Reducing coke oven emissions with other technologies - The use of pulverized coal injection technology substitutes pulverized coal for a portion of the coke in the blast furnace. Use of pulverized coal injection can replace about 25 to 40% of... 

NSF International Certification Criteria for Drinking Water Treatment Units Various papers on adsorption and other technologies for drinking and wastewater applications, http //nsf.org/consumer/dwtuconsumer.html... 

Chemical treatment is a class of processes in which specific chemicals are added to wastes or to contaminated media in order to achieve detoxification. Depending on the nature of the contaminants, the chemical processes required will include pH adjustment, lysis, oxidation, reduction or a combination of these. Thus, chemical treatment is used to effect a chemical transformation of the waste to an innocuous or less toxic form. In addition, chemical treatment is often used to prepare for or facilitate the treatment of wastes by other technologies. Figure 12 identifies specific treatment processes which perform these functions. 

Can ozone be used as the only means of water disinfection in a treatment facility If not, why not, and what other technologies do you think would work in combination with ozone treatment ... 

Major differences between ED and other processes are, first, the solute is transferred across the membrane against water in the other technologies discussed below, whereas only ionic species are removed by ED. As noted, two different membranes (anionic and cationic) are employed. Current consumption depends primarily on the TDS concentration. You should look at this very closely when comparing the operating cost benefits and tradeoffs of this technology to other options. Current efficiency can be calculated from the following formula ... 

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