Hazardous waste, reducing

The recycling option is less preferable and should be resorted to after all feasible source reduction options have been explored and implemented. Onsite recycling has a higher priority than offsite recycling because reducing transportation, storage and other handling of hazardous wastes reduces the risks to health and the environment. 

The surviving U.S. plants have embraced all types of waste treatment processes (see Wastes treatment, hazardous waste Wastes, industrial). The most desired poUution prevention processes are those which reduce the total amount of waste discharged. Treatment and disposal are less strongly emphasized options. Zero wastewater discharge faciHties and water recycling processes are becoming more common (55,56). 

Clean Air Act and its amendments ia 1970, 1977, and 1990 1967 Air Quahty Standards and National Air Pollution Acts and 1970 National Environmental PoHcy Act) (2) better waste disposal practices (1965 SoHd Waste Disposal Act 1976 Resource Conservation and Recovery Act) (see Wastes, industrial Waste treatment, hazardous wastes) (i) reduced noise levels (1972 Noise Control Act) (4) improved control of the manufacture and use of toxic materials (1976 Toxic Substances Control Act) and (5) assignment of responsibiUty to manufacturers for product safety (1972 Consumer Product Safety Act) (15,16). 

Cutting ChemicalWastes—What 29 Organic ChemicalPlants Are Doing to Reduce Hazardous Wastes, Infonn, Inc., New Yoik, 1985. 

Reduce or eliminate the generation of hazardous waste as expeditiously as possible... 

Pohution prevention techniques must be evaluated through a thorough consideration of ah media, hence the term multimedia. This approach is a clear departure from previous pollution treatment or control techniques where it was acceptable to transfer a pollutant from one source to another in order to solve a waste problem. Such strategies merely provide short-term solutions to an ever increasing problem. As an example, air pollution control equipment prevents or reduces the discharge of waste into the air but at the same time can produce a solid (hazardous) waste problem. 

Equipment for Superfund Waste Shipment RCRA hazardous waste that has been spilled, improperly landfilled, or dredged from defunct lagoons is a CERCLA waste, more commonly referred to as a Superfuna waste. For clean-ups where offsite treatment is the chosen solution, soil is excavated and placed in 15-m roll-off box or dump body truck. The trucks may be lined with polyethylene to reduce... 

Processing of Hazardous Wastes As with conventional solid wastes, the processing of hazardous wastes is undertaken for three purposes (1) to recover useful materials, (2) to reduce the amount of wastes that must be disposed in landfills, and (3) to prepare the wastes for ultimate disposal. 

Table 28-2 lists some of the currently used pretreatments and ultimate disposal methods for hazardous wastes (6). Pretreatment refers almost entirely to thickening or dewatering processes for liquids or sludges. This process not only reduces the volume of the waste but also allows easier handling and transport. 

Sol-gel. A limited evaluation of sol-gel coatings on stainless steel has been reported with the goal of reducing hazardous wastes and other environmentally undesirable materials [22]. In this study, the GTMS/TPOZ sol-gel discussed... 

It is important to note that EAF dust is a hazardous waste because of its high concentrations of lead and cadmium. With 550,000 tons of EAF dust generated annually in the U.S., there is great potential to reduce the volume of this hazardous waste. The motivation for reducing this waste not only lies with the cost of air pollution controls, but with the cost for disposal. U.S. 

Now you can reconsider the material balance equations by adding those additional factors identified in the previous step. If necessary, estimates of unaccountable losses will have to be calculated. Note that, in the case of a relatively simple manufacturing plant, preparation of a preliminary material-balance system and its refinement (Steps 14 and 15) can usefully be combined. For more-complex P2 assessments, however, two separate steps are likely to be more appropriate. An important rule to remember is that the inputs should ideally equal the outputs - but in practice this will rarely be the case. Some judgment will be required to determine what level of accuracy is acceptable, and we should have an idea as to what the unlikely sources of errors are (e.g., evaporative losses from outside holding ponds may be a materials loss we cannot accurately account for). In the case of high concentrations of hazardous wastes, accurate measurements are needed to develop cost-effective waste-reduction options. It is possible that the material balance for a number of unit operations will need to be repeated. Again, continue to review, refine, and, where necessary, expand your database. The compilation of accurate and comprehensive data is essential for a successful P2 audit and subsequent waste-reduction action plan. Remember - you can t reduce what you don t know is therel... 

Corrective Action Application At a hazardous waste treatment storage and disposal facility in Washington State, a cyanide-bearing waste required treatment. The influent waste stream contained 15 percent cyanide. Electrolytic oxidation was used to reduce the cyanide concentration to less than 5 percent. Alkaline chlorination was used to further reduce the cyanide concentration to 50 mg/1 (the cleanup objective). The electrolytic process was used as a first stage treatment because the heat of reaction, using alkaline chlorination to treat the concentrated cyanide waste, would be so great that it would melt the reactor tank. 

Moderate Use less hazardous conditions Reduce wastes ... 

A three-step nitration process of toluene is described. The advantages of the modified process are reduced waste, less hazardous operation, reduced oleum requirement, partial replacement of coned HN03 with dil HN03, and higher rate of toluene flow into the reactor (Ref 86) The continuous process of H.C. Prime (Ref 73) for preparing TNT was studied by thin-layer chromatography on silica gel with a starch binder and a fluorescent indicator. The nitration... 

Schofield, W.R. Lutzman, John Patterson, Gene W. Use of Chemical Additives to Reduce The Impact of Slag Formation in Hazardous Waste Incineration. Hazardous Materials Control Journal, USA, 1992. 

Likewise, fly ash from power plant combustors often contains small amounts of metals or their oxides, which require costly disposal in the ever-shrinking number of approved hazardous waste landfills. Thus, there are economic incentives to recover the metal values as well as to reduce the costs of ultimate disposal. Here, too, the metal content is low, and research is needed to develop economical separation processes. In principle, advances in this area could be translated into recovery of metal values from mine tailings. 

It is the formation of this material which makes the reaction have a low atom economy and, owing to the cost of disposal (usually by conversion to calcium phosphate and disposal as hazardous waste), has limited its commercial usefulness to high value products. Several methods have been developed to recycle (Ph)3PO into (Ph)3P but these have proved more complex than might be expected. Typically the oxide is converted to the chloride which is reduced by heating with aluminium. Overall this recovery is expensive and also produces significant amounts of waste. 

The public was outraged. It did not matter whether the pollution came from a chemical factory, power utilities, mines, petroleum, automobiles, or semiconductors the chemical industry s reputation was in free-fall. In 1990, the U.S. Congress established the Super Fund, requiring industry to pay for cleaning up hazardous waste. Major chemical manufacturers banded together in a voluntary effort to reduce factory emissions to almost zero and to police themselves. At the opposite extreme, some environmentalists called for the elimination of all toxic substances. 

All metal finishing facilities have one thing in common—the generation of metal-containing hazardous waste from the production processes. Reducing the volume of waste generated can save money and at the same time decreases future liabilities. Typical wastes generated are as follows ... 

Waste assessments are used to list the sources, types, and amounts of hazardous waste generated to make it easier to pinpoint where wastes can be reduced. 

Liquid coating materials with low organic solvent content should be used to minimize the amount of volatile organic compounds that will be volatized and to reduce the volume of solid and liquid hazardous waste created. 

Nonhazardous coating solids and water should be segregated from hazardous solvents and thinners, and containers labeled to prevent mixing. Separation of the materials reduces the amount of hazardous waste that is produced. Coating material solids can be dried and treated as a solid waste allowing for disposal in a landfill. 

To reduce as expeditiously as possible the amount of waste generated, including hazardous waste. 

Hazardous waste generators To ensure proper and safe waste management, the RCRA regulations provide management standards for those facilities that produce hazardous waste and provide reduced regulations for facilities that produce less waste. 

Land disposal restrictions (LDR) To reduce the hazards posed by permanently land-disposed waste, this program requires effective and expeditious hazardous waste treatment. 

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