Hazardous corrosive wastes

N.B., this value is of particular significance in the USA, where the definition of hazardous corrosive wastes specifically excludes lime sludges, by defining a liquid as hazardous when it has a pH of 12.5, or greater, at the standard reference temperature of 25 °C.)... 

In the past, hazardous wastes were often grouped into the following categories (1) radioactive substances, (2) chemicals, (3) biological wastes, (4) flammable wastes, and (5) explosives. The chemical cate-goiy included wastes that were corrosive, reactive, and toxic. The principal sources of hazardous biological wastes are hospitals and biological-research facilities. 

It is unusual to find a hazardous-waste-transfer facility at which wastes are simply transferred to larger transport vehicles. Some processing and storage facihties are often part of the materials-handliug sequence at a transfer sec tion. For example, neutralization of corrosive wastes will resiilt in the use of lower-cost holding tanks on transport vehicles. 

Reduction in VOC emissions Reduced user exposure to harmful materials Reduced hazardous production waste Possibly less expensive Stability of formulation at low temperatures Acceptability of drying rate Energy costs for drying Adequacy of corrosion resistance Wear properties High gloss properties Storage stability Water resistance... 

Corrosive wastes are acidic or alkaline (basic) wastes which can readily corrode or dissolve flesh, metal, or other materials. They are also among the most common hazardous wastestreams. Waste sulfuric acid from automotive batteries is an example of a corrosive waste. U.S. EPA uses two criteria to identify corrosive hazardous wastes. The first is a pH test. Aqueous wastes with a pH greater than or equal to 12.5, or less than or equal to 2 are corrosive under U.S. EPA s rules. A waste may also be corrosive if it has the ability to corrode steel in a specific U.S. EPA-approved test protocol. 

Any chemical substance, if improperly managed or disposed of, may pose a danger to living organisms, materials, structures, or the environment, by explosion or fire hazards, corrosion, toxicity to organisms, or other detrimental effects. In addition, when released to the environment, many chemical substances can be classified as hazardous or nonhazardous. Consideration must be given to the distribution of chemical wastes on land systems, in water systems, and in the atmosphere. 

Hexavalent chromate [Cr(VI)] is still used within the industry to meet critical high corrosion control and other metal surface finishing requirements. Cr(VI) is toxic and its control generates a hazardous, costly waste. 

The chemistry of chlorine, as well as other halogens, plays an important role in combustion and in a number of industrial processes. The reactions of chorine and chlorinated hydrocarbons are important in incineration of hazardous chemical wastes, which frequently contain these compounds. Also fuels such as biomass may contain significant amounts of chlorine. In biomass combustion, chlorine interacts with sulfur and alkali metals, a chemistry that has considerable implications for aerosol formation, deposit formation, and corrosion but is rather poorly understood. 

Hazardous chemical waste is defined in RCRA regulations as a solid waste that exhibits the characteristic of ignitability, corrosivity, reactivity, or toxicity, or is a specifically listed waste. The definition of hazardous waste specifically excludes radioactive material (source, special nuclear, or byproduct material) defined in AEA. 

Some existing waste classification systems are quantitative. For example, the concentrations of radionuclides defining the different subclasses of low-level radioactive waste that is generally acceptable for near-surface disposal are clearly stated in the regulations (NRC, 1982a), as are the quantitative conditions defining ignitable, corrosive, reactive, and toxic hazardous chemical wastes (see Section 4.2.1.1). 

Downey KW, Snow RH, Hazlebeck DA, Roberts AJ. Corrosion and chemical agent destruction, research on supercritical waste oxidation of hazardous military waste. Innovations in Supercritical Fluids, Chapter 21. Washington, D.C. American Chemical Society, 1995. 

Use separate labeled containers for general trash, broken glass, for each type of hazardous chemical waste—ignitable, corrosive, reactive, and toxic. 

Salt precipitation and corrosion are the technical key problems of the economical solution which will make the SCWO process an important tool for the treatment of hazardous organic wastes. 

RCRA, 40CFR261.30 hazardous codes, A B C D E and F, which represent corrosive waste (A) toxicity characteristic waste (B) acute hazardous waste (C) ignitable waste (D) reactive waste (E) and toxic waste (F) respectively A B C D E F... 

If a waste cannot be found on one of the RCRA lists, this does not mean it is not hazardous. Unlisted waste must still be tested to determine if it has certain properties or characteristics that render it hazardous. A waste is hazardous if it has one or more of the following properties ignitability, corrosivity, reactivity, or toxicity. 

During the past 30 years many new solvents for inorganic deposits were developed. Low hazard corrosion inhibitors have replaced some of the more toxic materials used to protect the structural surfaces during cleaning. Development of nuclear cleaning methods has extended the life of some very valuable nuclear generating plants. New waste disposal methods have enabled the industry to continue to operate, but have required new chemicals to be developed. Modest improvements for cleaning CP/R equipment include ways to remove FeS and we have seen the development of more environmentally friendly solvents. 

All nonproduct hazardous outputs into all environmental media, even though they may be within permitted or licensed limits. This is much broader than the legal definition of hazardous solid waste in the Resource Conversation and Recovery Act, its amendments, and subsequent regulations. Hazardous refers to harm to human health or the environment as is broader than the term toxicity. For example, wastes that are hazardous because of their corrosive, flammability, explosiveness, or infectiousness are not normally considered toxic. [p. 31]... 

The U.S. Environmental Protection Agency (EPA), in regulating hazardous waste, uses pH value as the criterion for determining if a substance is corrosive. Wastes with a pH of less than 2.0 or greater than 12.5 are considered to be corrosive. 

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