Hazardous waste streams

Samplers and Sample Procedure for Hazardous Waste Streams, EPA-600/2-80-018, U.S. EPA, Washington, D.C. 

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) ... 

How does the system interact widi die enviromiient (e.g., hazardous waste streams, to.xic releases, etc.)... 

The effectiveness of incineration has most commonly been estimated from the heating value of the fuel, a parameter that has little to do with the rate or mechanism of destraction. Alternative ways to assess the effectiveness of incineration destraction of various constituents of a hazardous waste stream have been proposed, such as assessment methods based on the kinetics of thermal decomposition of the constituents or on the susceptibility of individual constituents to free-radical attack. Laboratory studies of waste incineration have demonstrated that no single ranking procedure is appropriate for all incinerator conditions. For example, acceptably low levels of some test compounds, such as methylene chloride, have proved difficult to achieve because these compounds are formed in the flame from other chemical species. 

Austria showed a 60% reduction in solvent used by customers. Virtually all of that solvent would have been released into the environment or would have become a hazardous waste stream to be managed. 

The BIF must achieve a DRE of 99.99% for each POHC in the hazardous waste stream during the unit s compliance test, known as the trial burn.5 This means that for every 10,000 molecules entering the unit, only one molecule of the POHC is released to the atmosphere. In addition, due to an increased threat to human health and the environment from dioxin, the required DRE for POHCs in dioxin-bearing wastes has been established at 99.9999%, or one released molecule for every 1 million burned. It is important to note that this DRE standard applies only to permitted units. 

There are five classes of injection wells (Class I through V). Class I disposal wells are used for the disposal of industrial and hazardous waste streams, and may also be subject to certain RCRA, Subtitle C hazardous waste management regulations. Class II wells are defined as those wells used in conjunction with oil and gas production activities. Class III wells are defined as those wells that inject fluids ... 

Grosse DW. 1986. Treatment technologies for hazardous wastes part IV. A review of alternative treatment processes for metal-bearing hazardous waste streams. J Air Pollut Control Assoc 36 603-614. 

Carnes RA. 1978. Combustion characteristics of hazardous waste streams. Proc Annu Meet Air Pollut Control Assoc Paper 78-37.515 1-15. 

In fact, regulatory drivers are often seen as instrumental in spurring innovation. An assessment by a major aerospace manufacturer of what drives innovation towards safer processes for hazardous waste streams revealed that The regulatory drivers for waste reduction are familiar to most by now, and may be summarised into three categories of legislation 1) inventory reporting, 2) emission reporting, and 3) employee exposure levels. Anticipation of future restrictions was a decisive factor in this project. ... 

Pesticides are very much a part of the definition of hazardous wastes (Table 11). In fact, the toxicity characteristic of hazardous waste as defined by RCRA (referred to as extraction procedure or EP toxicity) is based on threshold concentrations of eight metals and six pesticides in an extract of the waste (Table II-A). Sixteen of the specific hazardous waste streams listed by... 

Assessment of a company s waste minimization needs includes examining the content of and volume of hazardous waste streams it generates, and the processes or operations that generate them. The object of this step is to prioritize the needs of the company, based on environmental risk, liability, and economic criteria. 

The salt baths in some nitriding and cyaniding processes also constitute hazardous wastes when spent. Nitriding and cyaniding baths for example, contain sodium and potassium cyanide and cyanate. Implementation of gas nitriding eliminates this waste stream. Gas nitriding employs ammonia gas to supply the nitrogen, and produces no hazardous waste stream. 

Wood, D.J., Law, J.D., Tullock, P.A. Extraction of lead and strontium from hazardous waste streams by solvent extraction with 4,4 ,(5 )-di-(t-butyldicyclohexo)-18-crown-6. Solvent Extr. Ion Exch. (1997), 15 (1), 65-78. 

Listed wastes are hazardous waste streams from specific and non-specific sources, listed under codes F, K, P, and U in 40 Code of Federal Regulations (CFR) Part 261.4... 

Heimbuch JA, Wilhelmi AR. 1985. Wet air oxidation - a treatment means for aqueous hazardous waste streams. J Hazard Mater 12 187-200. 

The modem technological needs of stmctural materials are not fulfilled entirely by these two types of materials. There is also a need for materials that exhibit properties in between cement and sintered ceramics. That need can be met by CBPC matrix composites—materials that are produced like cements at ambient or at slightly elevated temperatures, but exhibit properties of ceramics. These composites are attractive for many stmctural applications, including architectural products, oil-field drilling cements, road repair materials that set in very cold environments, stabilization of radioactive and hazardous waste streams, and biomaterials. 

The waste streams may be disposed safely if they do not contain contaminants that are harmful to living beings. Several waste streams, however, contain harmful chemicals that enter the human body through the food chain via soil or water or the air that we breathe. These contaminants may be toxic chemicals or radioactive. The former is referred to as hazardous , and the latter as radioactive . Both need treatment to isolate the contaminants from the groundwater, air, and soil prior to disposal. Treatment of hazardous waste streams is the subject of this chapter, while treatment of radioactive wastes, or those containing both hazardous and radioactive contaminants ( mixed wastes), is discussed in Chapter 17. 

The overall phosphate stabilization of hazardous waste streams may be put in two categories simple phosphate washing to stabilize most of the contaminants and actual formation of a CBPC waste to treat more difficult contaminants. These two approaches are described below. 

Most hazardous waste streams contain contaminants (Pb, Cd, Ni, and Zn) that can be treated by contacting with a phosphate solution. This treatment entails simply washing the waste stream with a phosphate solution. The amount of phosphate stabilizer is small (5 wt%). At the end of the treatment, the waste stream retains its free-flowing characteristics and hence is easy to load on a truck, or to pump at a disposal site. Because the waste volume does not increase due to this treatment, disposal cost is low. Furthermore, the binder cost is also kept to a minimum. 

Literature on Phosphate Treated or Tested Hazardous Waste Streams. 

Unlike the case for hazardous waste streams using phosphates, the literature on stabilization of radioactive waste streams using CBPC processes is mainly limited to work... 

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