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Waste, removal metals

Whereas many of these technologies are not really new, they have never had the regulatory and economic justification for their use in metallizing. Each of these general methods has many variants. Some may be directed to waste treatment, some to recycle, and some to reclaim. An example is filtration, used to prevent release to air of zinc particles from flame spraying, microfiltration of cleaners to extend hfe, in combination with chemical precipitation to remove metal particles from wastewater, and many other uses. [Pg.140]

PermeOx is also used to improve the bioremediation of soils contaminated with creosote or kerosene (see Bioremediation (Supplement)), to deodori2e sewage sludges and wastewater (see Odormodification), and to dechloriaate wastewater and effluents. A special formulation of calcium peroxide, made by FMC and sold ia the United States under the trademark Trap2ene, is used for removing metal ions from acidic waste streams such as coal ash leachate and acid mine drainage (see Wastes, industrial). [Pg.91]

Dehydration The growing use of isopropanol as a clean-rinse fluid in microelectronics produces significant quantities of an 8.5-90 percent isopropanol waste. Removing the water and trace contan ii-nants is required before the alcohol can be reused. Pervaporation produces a 99.99 percent alcohol product in one step. It is subsequently polished to remove metals and organics. In Europe, dehydration or ethanol is the largest pei vaporation application. For the very large ethanol plants typical of the United States, pei vaporation is not competitive with thermally integrated distillation. [Pg.2055]

PRECP Precipitation Precipitation removes metal and inorganic solids from liquid wastes to allow the safe disposal of the hazardous solid portion... [Pg.453]

Phytotech also developed a related technology, called rhizofiltration, that uses adsorption by plant roots to remove metals from aqueous waste streams. This process involves the use of hydro-ponically grown plants to filter out targeted contaminants. Both technologies are commercially available through Edenspace. [Pg.523]

Researchers at Oregon State University are currently studying apphcations of chitosan beads for the removal of toxic metal ions from wastewater. Chitosan has potential applications to waste removal because it selectively adsorbs toxic Group III transition metal ions in preference to less dangerous alkali or alkaline earth metal ions. The technology has been the focus of bench-scale studies and is not commercially available but it is available for licensing. [Pg.845]

The Polylonix Separation Technologies, Inc., polymer filtration is a separation technology that removes metals from aqueous waste streams. Specialized, water-soluble polymers are added... [Pg.878]

Elimination of metal ions is a second major function of supported chelators. And a variety of conditions may be envisioned. Electroplating firms can be faced with the need to remove metal ions from solutions as part of an EPA-approved disposal protocol. A radiator shop may be faced with a need to remove waste zinc ion before allowing water to go into a sewer, in an effort to minimize the danger of killing bacteria used in sewage treatment procedures. The Berkeley Pit (vide infra) represents an outstanding example of the need to remove waste copper. [Pg.124]

A very similar method has been used by Lin and Ganesan to produce (V-acyl-iV -carbamoylguanidines.38 The activating agent used by them was mercuric chloride, and the waste heavy metal was removed by filtration at the end of the synthesis. Scheme 16 shows two compounds prepared by this method. [Pg.12]

While minimizing blowdown volumes can be quite effective in reducing waste, removing the hazardous metals component of the waste stream can have a more dramatic effect on reducing the impact of the blowdown on the environment. Chromate based corrosion inhibitors have historically been the mainstay of cooling water treatment systems. But in recent years, some plants have elected to use nonchromate inhibitors in order to reduce the potential environmental problems associated with chromates. Types of nonchromate inhibitors that have proved useful and that have in some situations performed as well as chromates include (Roti 1985) ... [Pg.103]

A New Bedford Harbor Sawyer Street site in Massachusetts has been designated as a superfund site due to PCB contamination of river sediments. Commodore was one of three companies chosen to conduct demonstration studies on-site under contract to Foster Wheeler Environmental Company. The river sediment was first washed with diisopropylamine by the Ionics RCC B.E.S.T process [35], producing an oil concentrate. The PCB level in the B.E.S.T concentrate was approximately 32,800 ppm. Dioxins/furans (TEFs) were also present at 47 ppm. This concentrate was reacted with SET in the SoLV process to destroy the PCBs and dioxins (Table 4). After treatment, the PCB level was 1.3 ppm, well below regulatory requirements for disposal in nonhazardous waste landfills. Dioxins were also readily remediated. This study also illustrates that the SoLV process can remove metals from substrates. The concentrate received was found to have lead, arsenic, and selenium in high parts-per-billion levels. After treatment with the SoLV process, the levels were below detection limits. The metals were... [Pg.359]

Finally, soil remediation processes are farther along than the remediation of low-level waste because some practical tests have been made in the field. In some systems, the results are those desired. The costs of the thermal process for removing metal from soils are so high that funding of the development of the electrochemical approach would seem to offer good returns. [Pg.526]

Bivalve molluscs effectively concentrate many trace elements (1-13). They are filter feeders and as such maintain a flow of water through their gills for feeding, respiration, and the removal of metabolic wastes. Trace metals occur in many physicochemical forms in water, and thus can enter animals by their ingestion of living and nonliving particulate material suspended in the water and from the sorption of substances dissolved in the water. We know neither the rates of accumulation nor the effects of physicochemical form on accumulation of many of the critical elements in most animals. [Pg.611]

Almost all of the cathodic (reduction) processes used for waste removal are metal recovery processes. Although electrodialysis, gas treatment, and some oxidant synthesis processes make use of cathodic reactions, these will be discussed later under other headings. [Pg.365]

Two methods that immobilize or remove metal pollutants from coal wastes (Category 1) are calcining and preleaching, respectively. Our laboratory results... [Pg.619]


See other pages where Waste, removal metals is mentioned: [Pg.809]    [Pg.1808]    [Pg.330]    [Pg.370]    [Pg.394]    [Pg.116]    [Pg.141]    [Pg.21]    [Pg.296]    [Pg.109]    [Pg.526]    [Pg.330]    [Pg.49]    [Pg.127]    [Pg.809]    [Pg.269]    [Pg.65]    [Pg.12]    [Pg.320]    [Pg.326]    [Pg.146]    [Pg.1174]    [Pg.315]    [Pg.95]    [Pg.149]    [Pg.269]    [Pg.256]    [Pg.71]    [Pg.1568]    [Pg.640]    [Pg.940]    [Pg.28]   


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