Processing of Hazardous Waste

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. 

Processing Techniques The processing of hazardous wastes on a batch basis can be accomplished by physical, chemical, thermal, and biological means. The various individual processes in each categoiy are reported in Table 25-63. Clearly, the number of possible treatment-process combinations is staggering. In practice, the physical, chemical, and thermal treatment operations and processes are the ones most commonly used. 

To determine whether the character of a residue has been significantly affected by the burning or processing of hazardous waste, and thus whether the Bevill exemption can be claimed, one of two criteria must be met. As long as the residue meets either criterion, it will qualify for the Bevill exclusion. 

Resource Conservation and Recovery Act (U.S.). Legislation dealing with licenses, fees, and accountability for the processing of hazardous wastes. 

Thermal treatment is used to destroy, break down, or aid in the desorption of contaminants in gases, vapors, Hquids, sludges, and soHds. There are a variety of thermal processes that destroy contaminants, most of which are classified as incineration. Incineration HteraHy means to become ash (from Medieval Latin, incinerare in or into ashes). With respect to the incineration of hazardous wastes regulated in the United States, however, there is a strict legal definition of what constitutes an incinerator. The Resource Conservation and Recovery Act (RCRA) definition of incinerator at 40 CFR 260.10 is... 

Assessment Phase The assessment phase aims to collect data needed to identify and analyze pollution-prevention opportunities. Assessment of the facility s waste-reduction needs includes the examination of hazardous waste streams, process operations, and the identification of techniques that often promise the reduction of waste generation. Information is often derived from obsei vations made during a facihty walk-through, interviews with employees (e.g., operators, line workers), and review of site or regulatory records. One professional organization suggests the following information sources be reviewed, as available (Ref. 7) ... 

The general purpose of ultimate disposal of hazardous wastes is to prevent the contamination of susceptible environments. Surface water runoff, ground water leaching, atmospheric volatilization, and biological accumulation are processes that should be avoided during the active life of the hazardous waste. As a rule, the more persistent a hazardous waste is (i.e., the greater its resistance to breakdown), the greater the need to isolate it from the environment. If the substance cannot be neutralized by chemical treatment or incineration and still maintains its hazardous qualities, the only alternative is usually to immobilize and bury it in a secure chemical burial site. 

Solidification/Stabilization technologies are techniques designed to be used as final waste treatment. A major role of these processes is posttreatment of residuals produced by other processes such as incineration or chemical treatment. In some cases, solidification/ stabilization processes can serve as the principal treatment of hazardous wastes for which other detoxification techniques are not appropriate. High volume, low toxicity wastes (such as contaminated soils) are an example of this application. 

Fitzpatrick, V. F. Timmerman Buelt, J. L., In situ vitrification - A candidate process for in situ destruction of hazardous waste Pacific West Laboratory, PNL-SA-14065 (1986)... 

In establishing treatment standards, U.S. EPA applied the BDAT methodology to the typical forms of waste generated by industry. Some forms of hazardous waste are unique and were not taken into account by the BDAT process when treatment standards were established. As a result, U.S. EPA created a number of broad ATSs for special types of waste.2... 

This chapter will introduce the entire hazardous waste identification process, but will focus particularly on the final steps and the characteristics and properties of hazardous wastes. After reading this chapter, one will be able to understand the hazardous waste identification process and the definition of hazardous waste, and be familiar with the following concepts ... 

The final steps in the hazardous waste identification process determine whether a waste poses a sufficient chemical or physical hazard to merit regulation. These steps in the hazardous waste identification process involve evaluating the waste in light of the regulatory definition of hazardous waste. The remainder of this chapter explains the definition, characteristics, and properties of hazardous wastes. 

Mining and mineral processing wastes. Certain wastes from the mining, refining, and processing of ores and minerals are excluded from the definition of hazardous waste. 

The K list of hazardous wastes designates particular wastes from specific sectors of industry and manufacturing as hazardous. The K list wastes are therefore known as wastes from specific sources. Like F list wastes, K list wastes are manufacturing process wastes. They contain chemicals that have been used for their intended purpose. To determine whether a waste qualifies as K-listed, two primary questions must be answered. First, is the facility that created the waste within one of the industrial or manufacturing categories on the K list Second, does the waste match one of the specific K list waste descriptions There are 13 industries that can generate K-list wastes1 2 3 ... 

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