Chemicals treatment of waste

Perma-Fix Environmental Services, Inc. (Perma-Fix), has developed the Perma-Fix Process for the neutralization and stabilization of hazardons, radioactive, and mixed wastes. The Perma-Fix Process is a two-step treatment involving proprietary chemical treatment of wastes followed by the addition of stabilization chemicals to create a final waste form with the hazardous component of the wastes neutrahzed. The technology has been used commercially for several years. 

The chemical treatment of wastes can result in the material being converted to products that are nontoxic and environmentally acceptable. The methods fall into several categories that include acid/base neutralization, oxidation or reduction, and precipitation of toxic ions as insoluble solids. Many of the disposal procedures suggested in this book fall into these categories. 

REDUCTION AND OXIDATIVE TREATMENT OF FOSSIL FUELS AND OTHER CHEMICAL TREATMENTS OF WASTE STREAMS... 

Many of the contaminants are highly stabilized organic compounds that are not destroyed by biological or chemical treatment of wastes, and they often survive the self-purification that normally occurs in moving streams. One synthetic chemical in waste, orthonitrochloro-benzene, was detectable in the Mississippi River for a distance of over 900 miles from the point of origin.70... 

In order to cope with water scarcity and pollution of the hydrosphere, two main strategies of water treatment are applied (1) chemical treatment of polluted drinking water, surface water, groundwater and (2) chemical treatment of waste-waters containing biocidal or non-biodegradable components. 

A critical part of the regnlation is to rednce and, where possible, eliminate the generation of hazardons waste. Waste minimization was specifically mandated in the 1984 Hazardous and Solid Wastes Amendments to the Resource Conservation and Recovery Act. This has had an enormous impact on the way waste is handled by printed circuit board facilities. Prevention of pollution has become the overriding goal in design with recycle and reuse technologies implemented only where pollution prevention is not feasible for technical and/or economic reasons. Chemical treatment of wastes should be utilized only where no other options exist. 

Chemical treatment of wastes involves the addition of chemicals to precipitate metals out of solution. This results in a sludge which must be disposed of. The sludge is then typically sent to a reclaimer for recovery of the metals or licensed disposal site. The latter option is becoming increasingly difficult and expensive. It should be avoided due to the unknown risks associated with the landfill of hazardous wastes. Chemical treatment of wastes should be utilized only when pollution prevention or recycling is not technically or economically feasible. 

Common unit operations in chemical treatment of wastes are... 

The radicals are then involved in oxidations such as formation of ketones (qv) from alcohols. Similar reactions are finding value in treatment of waste streams to reduce total oxidizable carbon and thus its chemical oxygen demand. These reactions normally are conducted in aqueous acid medium at pH 1—4 to minimize the catalytic decomposition of the hydrogen peroxide. More information on metal and metal oxide-catalyzed oxidation reactions (Milas oxidations) is available (4-7) (see also Photochemical technology, photocatalysis). 

The treatment of waste is the third element of the hierarchy and should be utilized only in the absence of feasible source reduction or recychng opportunities. Waste treatment involves the use of chemical, biological, or physical processes to reduce or eliminate waste material. The incineration of wastes is included in this categoiy and is considered preferable to other treatment methods (i.e., chemical, biological, and physical) because incineration can permanently destroy the hazardous components in waste materials (Ref. 4). It can also be employed to reduce the volume of waste to be treated. 

In this section, report only information about treatment of wastestreams at vour facilitv. not about off-site treatment. If you do not perform on-site treatment of wastes containing the chemical being reported, check the Not Applicable (NA) space at the top of Section 7. 

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. 

Sludges from physical-chemical treatment of industrial waste streams containing heavy metals... 

Paper and board are composed of cellulose obtained by the mechanical or semi-chemical treatment of vegetable fibers (pulp) derived from various sources like wood, hemp, cotton, etc. In some cases waste and regenerated paper is used. 

The product resulting from the treatment of waste rubber (flash, used tyres, etc.) by heat and chemical agents, which effect sufficient break down and softening so that the reclaim may be used as a compounding ingredient in fresh compound without excessive degradation of physical properties. 

The U.S. Bureau of Mines-Reno Research Center is conducting research on the chemical treatment of process waste waters by ion elutriation for removing low levels of anions from cyanide solutions. This research has been coordinated with other centers for developing a waste water treatment system. 

Generally, a distinction can be made between membrane bioreactors based on cells performing a desired conversion and processes based on enzymes. In ceU-based processes, bacteria, plant and mammalian cells are used for the production of (fine) chemicals, pharmaceuticals and food additives or for the treatment of waste streams. Enzyme-based membrane bioreactors are typically used for the degradation of natural polymeric materials Hke starch, cellulose or proteins or for the resolution of optically active components in the pharmaceutical, agrochemical, food and chemical industry [50, 51]. In general, only ultrafiltration (UF) or microfiltration (MF)-based processes have been reported and little is known on the application of reverse osmosis (RO) or nanofiltration (NF) in membrane bioreactors. Additionally, membrane contactor systems have been developed, based on micro-porous polyolefin or teflon membranes [52-55]. 

The control and treatment system in this plant mainly relies on the chemical destruction of waste rather than biological processes. The plant generates a raw waste load as high as 400,000 lb BOD/day. From 1973 to 1974, the company reported a total waste flow of 3.5-4.3 MGD containing a BOD of 1710-1960 Ib/day, COD of 3700-4000 Ib/day, and TSS of 1040-1250 Ib/day. The treatment system included the following units ... 

Conventional chemical treatment of metal finishing wastes will usually produce clarified effluent acceptable for discharge however, in those applications where it is desirable or necessary to recover the clarified rinse water for re-use, the technologies are utilized to purify or "desalt" the effluent for re-use. 

Measurement of toxicity (biological analyses) The development of toxicity during chemical/biological treatment of waste waters was seldom assessed. Only in the last few years has the application of toxicity testing been reported more frequently (e. g. Diehl et al., 1995 Moerman et al., 1994 Jochimsen, 1997 Sosath, 1999). Moerman etal. (1994) showed that a toxicity balance around the whole process is important for combined chemical/biological treatment. It is not sufficient to assess the effect of ozonation alone (cf. chapter A 1). 

Despite the many failures encountered over the last decades in up-scaling photochemical reactions, industrial preparative photochemistry has not lost its image as an attractive tool for the synthesis of fine chemicals. Reaction conditions (solvent, temperature, work-up procedures) are, in general, quite flexible and facilitate implementation of such processes on an industrial scale in terms of environmental protection. In addition, light-induced oxidation processes exhibit a very promising potential for the chemical treatment of contaminated surface and ground waters, as well as for liquid and gaseous industrial waste. 

MARATHON-HOWARD PROCESS. A treatment of waste sulfite liquor from sulfite pulp manufacture In recover chemicals and reduce steam pollution. The waste sulfite is treated with line and precipitates. (I) calcium sulfite for use in preparing fresh cooking acid for the sulfite pulp process, and 121 a basic calcium salt tif ligmn sulfonic acid (lignin sullYmalesi that can be pressed and used as a fuel of used as raw- material for vanillin, lignin plasties, and other chemicals. The remaining liquor with its BOD reduced X() ( is the effluent. 

Myasoedov, B.F. 2007. Chemical treatment of high-level waste for utilization. An international spent nuclear fuel storage facility - Exploring a Russian site as a prototype. Proc of Int Workshop. Schweitzer, G.E., Sharber, A.C. Eds. National Academy of Sciences, Washington, DC, pp. 199-207. 

Environmental Pollution Control. The importance of chemical oxidation of reduced sulfur compounds lies in its application to treatment of wastes-treams from municipal sewage systems, acid mine drainage and industrial plants such as tanneries, paper and pulp mills, oil refineries and textile mills. 

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