Environment recycling

International Aluminium Institute, Aluminium Recycling Facts, http //www.wend-aluiTiinium.org/environment/recycling, last accessed 5.1.2007. 

Nonetheless, concern exists that after the useful lives of these batteries has ended, they may become a source of cadmium and nickel that reaches the environment. Recycling Ni-Cd batteries addresses this concern and also conserves valuable natural resources. 

Dawson AR (2000) Pfa and the environment Presented at workshop Source Term, Fate and Transport Models and Evaluation Approaches for Recycled Materials Uses in Various Applications in the Highway Environment Recycled Materials Research Center, University of New Hampshire, April 13-14... 

In aqueous waste-removal operations, the solute is often an undesirable species to be removed from wastewater. After solute recovery, the rich streams, with solute in low concentrations, are disposed of, returned to the environment, recycled, or reused. Clearly, when returned to the environment, these streams must meet the latest federal, state, or local regida-tions. When recycled or reused, solute concentrations must be sufficiently low to meet the requirements of sinks elsewhere in the process. 

Hewlett Packard, Recycling Program Overview, http //www.hp.com/hpinfo/globalcitizenship/ environment/recycle/index.html. 

If you manage hazardous wastes properly, there should be fewer hazards for you, your co-workers, your community, and the environment. Recycling and reducing the amounts of waste generated can also increase safety. In fact, used oil, lead-acid and nickel-cadmium batteries, scrap metal, pesticides, and mercury-containing thermostats should be re- cycled where possible. 

Materials selection depends on a wide variety and range of factors, including cost, technical suitability, safety, energy requirements in production and service, quality, the ability to be manufactured in the required quantities and to be satisfactorily assembled and finished, the influence of the service environment, recycling and waste recoverability, its estimated lifetime, and many other factors, which are often interrelated. All these elements must be considered before deciding that the use of a particular material makes good sense. 

Lead is in some types of batteries automobiles and other vehicles use lead-acid batteries, as do some alarm and emergency lighting systems (Wieman 2013). These batteries do not threaten human health when they are used. Problems occur when they are disposed of improperly. If they are landfilled or incinerated, lead can be released into the environment. Recycling is the best option for disposal of lead-acid batteries. 

The monomer recovery process may vary ia commercial practice. A less desirable sequence is to filter or centrifuge the slurry to recover the polymer and then pass the filtrate through a conventional distillation tower to recover the unreacted monomer. The need for monomer recovery may be minimized by usiag two-stage filtration with filtrate recycle after the first stage. Nonvolatile monomers, such as sodium styrene sulfonate, can be partially recovered ia this manner. This often makes process control more difficult because some reaction by-products can affect the rate of polymerization and often the composition may vary. When recycle is used it is often done to control discharges iato the environment rather than to reduce monomer losses. 

Cobalt. There is no U.S. mine production of cobalt. Refining of imported nickel—cobalt mattes has not occurred since the mid-1980s. About 1600 t of secondary cobalt was recycled from scrap by 13 faciUties in the United States representing - 22% of total U.S. consumption. The price of the metal was around 44/kg. Most is imported from Zaire and Zambia. Increasing quantities are coming from Russia. Historically, the price of cobalt has been quite volatile and dependent on the pohtical environment in those countries. Cobalt is used in superaHoys, 40% catalysts, 14% paint driers, 11% magnetic alloys, 10% and cemented carbides and other uses, 16%. 

The economic balance must be considered between recovery, reuse, and modification of a waste material or by-product and its disposal. The future is expected to bring iacreases ia the practice of recycle, recovery, modification, and upgrading of wastes of all sorts, and a reduction ia disposal by iaciaeration (qv), biochemical oxidation, or discharge to the environment (see Recycling). 

Other Chromates and Dichromates. The wet operations employed in the modem manufacture of the chromates and dichromates are completely enclosed and all stacks and vents equipped with scmbbers and entrainment traps to prevent contamination of the plant and its environment. The continuous process equipment that is used gready faciHtates this task. The trapped material is recycled. 

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