Chemical reclamation

Ion exchange plays an important part in waste treatment, chemical reclamation, and water recychng. Ion exchange is a reversible, chemically driven process that sorbs hazardous ions onto specially treated porous organic materials (usually beads) and replaces them with nontoxic ions. The sorbed ions are then chemically stripped from the beads and recovered in the form of a more concentrated solntion, called the regenerant. 

If chemical reclamation is the objective, process segregation is necessary. This is particularly true when chrome is to be recovered from rinse waters. Cyanide rinses, copper and nickel plating rinses, and alkahne or acid rinses must be removed from the chrome rinse waters. The rinse waters containing the chrome will first pass through a cation-exchange unit where the chrome-bath impurities, such as copper, nickel, and trivalent chromium, are removed.The hexavalent chromium is removed in the anion-exchange unit. If so desired, since the water has been deionized, it can be recycled as high-purity rinse water. 

In the United States, the largest concentration of atmospheric vanadium occurs over Eastern seaboard cities where residual fuels of high vanadium content from Venezuela are burned ia utility boilers. Coal ash ia the atmosphere also coataias vanadium (36). Ambient air samples from New York and Boston contain as much as 600—1300 ng V/m, whereas air samples from Los Angeles and Honolulu contained 1—12 ng V/m. Adverse pubHc health effects attributable to vanadium ia the ambieat air have aot beea deteroiiaed. lacreased emphasis by iadustry oa controlling all plant emissions may have resulted ia more internal reclamation and recycle of vanadium catalysts. An apparent drop ia consumption of vanadium chemicals ia the United States since 1974 may be attributed, in part, to such reclamation activities. 

Chemical Marketing Reporter 254, No.3, 20th July 1998, p.3/16 EVERGREEN RECYCLING IS BREAKING GROUND FOR NYLON RECLAMATION TulloA... 

Materials Reclamation Weekly 161,No.l7, 12th June 1993,p.l3/15 CHEMICAL TECHNOLOGY TO RECOVER QUALITY FEEDSTOCKS FROM USED PLASTICS... 

In-plant reclamation refers to the sand reclamation process in a foundry facility, which directly minimizes the generation of spent foundry sand. Sand reclamation includes physical, chemical, or thermal treatment of foundry sands so they may be safely substituted for new sand in molding and core-making mixes. 

Cooper, J.C., Hager, D.G. Water Reclamation with Activated Carbon , Chemical Engineering Progress, Oct. 1966, p. 85. 

Except for its lower protein concentration, glomerular filtrate at the top of the nephron is chemically identical to the plasma. The chemical composition of the urine is however quantitatively very different to that of plasma, the difference is due to the actions of the tubules. Cells of the proximal convoluted tubule (PCT) are responsible for bulk transfer and reclamation of most of the filtered water, sodium, amino acids and glucose (for example) whereas the distal convoluted tubule (DCT) and the collecting duct are concerned more with fine tuning the composition to suit the needs of the body. 

Power ultrasound can be used for the rehabilitation of industrial sites or the reclamation of polluted land by the removal of chemical and biological contamination from soil. There are two basic mechanisms through which this can occur either via the removal of contaminated material from the surface of soil particles or the leaching out of more deeply entrenched materials. 

T0242 ELI Eco Logic International, Inc., Gas-Phase Chemical Reduction (GPCR) T0253 Energy Reclamation, Inc., Pyrolytic Waste Reclamation (PWR)... 

The leaching behaviour of fly ash is of considerable interest in horticulture, and the literature is extensive. In addition to the reclamation of fly ash disposal sites, fly ash is used extensively as a soil conditioner. Acidic agricultural soils benefit from the addition of alkaline fly ash, and essential plant nutrients present in the ash, such as B, Ca, Mg, K, S, Mn, and Zn are also added improving both chemical and physical properties (Clark et al. 1995 Sikka Kansal 1995). In coal mining areas, acid mine drainage... 

The current state of the case study illustrated (Table 2) shows that technologies for reclamation (condensation, distillation, metal reclamation) or recycling (electrolyte production) are for the most part available for process emissions. Furthermore, chemicals with poor efficiency are currently used in the area of electroplating. 

McCarty, P. L. et al. Mutagenicity Activity and Chemical Characterization for the Palo Alto Reclamation and Groundwater Facility, U.S. Environmental Protection Agency. U.S. Government Printing Office Washington, DC, 1981 EPA 600/1-81-029. 

In the reclamation of chemically or resin bonded sands, the system employed must be able to break the bond between the resin and sand and remove the fines that are generated. The systems most commonly employed are wet washing and scrubbing for silicate bonded sands, or dry scrubbing/attrition and thermal (rotary drum or fluidized bed) systems for resin bonded sands. 

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