Chemical waste characteristics

A sohd waste is considered hazardous if it is either a Hsted waste or a characteristic waste. Listed wastes include a Hst of specific processes that generate a waste and a Hst of discarded commercial chemical products. There are four hazardous waste characteristics ignitabiHty, corrosivity, reactivity, and toxicity. The last refers to the leachabiHty of a waste and the resultant toxicity in the groundwater using the analytical method referred to as toxicity characteristic leaching procedure (TCLP). A Hst of substances included under TCLP is shown in Table 1. 

A variation for one vendor is shown in Figure 26. The design and control of the system takes into consideration the following parameters flow rate, water temperature, waste characteristics, chemical pretreatment options, solids loading, hydraulic loading, the air to solids ratio. Units are designed on the basis of peak flow rate expected. 

The sources of contamination are usually those hazardous materials that are contained in drums, tanks, surface impoundments, waste piles, and landfills, as well as heavily contaminated media (such as soil) affected by the original leaking or spilling source. The purpose of defining sources of contamination is to help to identify the source location, potential releases, and engineering characteristics that are important in the evaluation of remedial actions, as well as waste characteristics, such as the type and quantity of contaminants that may be contained in or released to the environment, and the physical or chemical characteristics of the hazardous wastes present in the source. 

Waste characteristics, which may limit the effectiveness or feasibility of the remedial technologies quantity/concentration, chemical composition, acute toxicity, persistence, biodegradability, radioactivity, ignitability, reactivity/corrosivity, infectiousness, solubility, volatility, density, partition coefficient, compatibility with chemicals, and treatability... 

A chemical waste is considered hazardous if it exhibits one or more of the following characteristics ignitability, corrosivity, reactivity, and toxicity. Under the authority of the Resource Conservation and Recovery Act (RCRA) and the U.S. Environmental Protection Agency (EPA), a hazardous substance has one or more of the foregoing characteristics. 

In addition to the classification of petrolenm-related chemicals by the characteristics described above, the U.S. Environmental Protection Agency designates more than 450 chemicals or chemical wastes that are specific snbstances or classes of substances known to be hazardous. Each such chemical or waste is assigned a hazardous waste number in the format of a letter followed by three nnmerals, where a different letter is assigned to snbstances from each of the following list ... 

Any hazardous chemical or chemical waste listed or having characteristics identified by the Resource Conservation Recovery Act, with the exception of those snspended by Congress nnder the Solid Waste Disposal Act... 

The final costs are highly dependent upon site-specific conditions. Contributing factors to the final cost include the waste characteristics, including its physical form and chemical makeup the amount of pretreatment required transportation of raw materials to the site and treated materials from the site and other random factors such as health and safety requirements and regulatory factors (D150141, p. 7.100). 

The identification of hazardous chemical waste based on its physical and chemical characteristics is discussed in Section 4.2. 

In addition to chemical waste that may be classified as hazardous based on one or more of the characteristics described above, a chemical waste may be classified as hazardous if it is specifically listed (EPA, 1980b). Chemical wastes are listed based on their source or the presence of specific hazardous substances. Listed hazardous wastes include wastes from nonspecific sources (the so-called F list), wastes from specific sources ( K list), acutely toxic hazardous waste from any source ( P list), and toxic (other than acute) waste from any source ( U list). 

LDRs specified in RCRA required EPA to develop treatment standards for hazardous chemical waste and established deadlines for EPA to develop treatment standards for those wastes for which treatment standards did not exist. Congress divided LDR hazardous waste into several categories solvents and dioxins California listed wastes first, second, and third listed wastes and characteristically hazardous wastes. 

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. 

Under current EPA regulations, a chemical waste is either hazardous or it is not, and there is no further classification of hazardous chemical waste with respect to the degree of hazard. Some states have defined classes of hazardous chemical waste (e.g., extremely hazardous waste) but, in practice, the requirements on management and disposal of all hazardous wastes have resulted in essentially the same approaches being used regardless of hazard. When a hazardous chemical waste is mixed with a nonhazardous solid waste, the entire waste is classified as hazardous unless the former is a characteristically hazardous waste that does not contain any listed waste and mixing with the nonhazardous waste removes the hazardous characteristic. 

For hazardous chemical waste, there is no federal classification system other than a specification that the waste is hazardous or that it can be managed as if it were nonhazardous because it has been shown not to be characteristically hazardous or has been delisted or specifically excluded.14 Hazardous chemical waste that is not... 

Significant parts of the existing waste classification systems are based on intrinsic properties of waste. The system for subclassifying low-level waste in 10 CFR Part 61 (NRC, 1982a) and the determination of whether a chemical waste is characteristically hazardous (see Section 4.2.1.1) are examples of waste classification based on intrinsic properties. 

The proposed framework for risk-based classification of all radioactive and hazardous chemical wastes developed in Section 6.2.2 represents waste classification in its broadest, most general terms. Thus, this classification system can be viewed as the highest level of a possible hierarchy of hazardous waste classifications (e.g., see Figure 4.2). Further subclassification of these broadly defined waste classes may be desirable for such purposes as protection of workers during waste operations, protection of public health and the environment following waste disposal, and development of efficient methods of waste management taking into account the characteristics of actual wastes. 

SDS at all sites in this study is characterized and managed according to the hazardous waste limits for chemical agents (mustard, GB, VX), as well as other hazardous waste characteristics. The SDS is containerized and stored in a permitted storage area prior to treatment and disposal. 

The response time of a chemical sensor should be appropriate for the application for which it is intended. For example, if the sensor is used to monitor acutely toxic (lethal) substances in the workplace, the response time should be faster than the biological/ toxicological re.sponse — perhaps only a few seconds. On the other hand, some applications, such as monitoring the spread of a chemical waste plume underground, have characteristic time scales of days to years, permitting utilization of sensors that respond more slowly. 

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