Remediation of wastes

Walton BT, Anderson TA. 1990. Microbial degradation of trichloroethylene in the rhizosphere Potential application to biological remediation of waste sites. Appl Environ Microbiol 56 1012-1016. 

Tpl, Inc., Albuquerque, NM Investigating the use of plants for Aqua Chem Analyses, Inc., Palm remediation of wastes contaminated with Bay, FL lead... 

Laboratory studies indicate that aquathermolysis can be used to aid in the remediation of waste oils, chromium (Cr VI) and volatile organic compounds (VOCs) in contaminated soils and aquifers. Aquathermolysis is particularly useful in lowering the viscosity of oil and increasing its mobility to facilitate further treatment. Potential applications range from treating household and industrial refuse to destruction of chemical warfare agents. 

The IT Corporation thermal destruction unit is a mobile unit that uses infrared incineration technology. The main objective of this process is to transform the feedstock into another form (an ash acceptable for delisting) while assuring safe discharge of exhaust gas products to the environment. The unit is capable of on-site remediation of wastes and soils contaminated with polychlorinated biphenyls (PCBs) and other organics. This technology is based on a conveyor belt furnace process. 

Water is cheap, relatively abundant in many part of the world, safe, and, when pure, environmentally benign [40]. It is also true that some reactions show unusual selectivity and/or rate enhancements when run in, or more accurately, on water [41]. However, a closer examination of many reactions in water reveals that in fact one or more liquid reagents have been used in large excess, so they are in fact biphasic reactions. There is also a misguided perception that water, after use as a reaction medium, can be poured down the drain [42]. On an industrial scale, there can be a considerable cost and environmental burden associated with remediation of waste water streams contaminated with solvents and organic and metal residues-see Chapters 2 and 3. 

It has been demonstrated that mixed oxides obtained from calcined LDHs have the ability to act as sorbents for a variety of anionic compounds from aqueous solution. This ability is because of the propensity for the mixed oxide to hydrate and re-form an LDH in such conditions and is of particular interest for the decontamination of waste-water. Hermosin et al. have found, for example, that MgAl-LDHs calcined at 500 °C are potential sorbents for the pollutants trinitrophenol and trichlorophenol from water [208, 209]. The adsorption mechanism was shown, using PXRD, to involve reconstruction of the LDH, with the uptake of the phenolate anions into the interlayers. Similarly, the ability of calcined MgAl-LDHs to remove nitriloacetate anions from solution has been demonstrated [210]. Calcined LDHs have been utilized also for the sorption of radioactive anions, such as 111, from aqueous solution [211]. A particularly attractive feature of the use of calcined LDHs for the remediation of waste-water is that the sorption capacity of the material may be regenerated via calcination of the rehydrated LDH. 

The synthesis of ibuprofen will now be used as an example of the determination of atom economy (see Cann, 2000). This synthesis results in rather small amounts of unwanted by-products, thus lessening the need for disposal and remediation of waste products. Ibuprofen is widely used for the relief of headache (including migraine). It is marketed as an analgesic agent for general pain conditions that arise from various injuries. The synthetic route commonly used is shown in Figure 12.13. 

How much money is being spent on remediation of waste ... 

Fuerstenau, M. C. and K. N. Han, eds. 2003. Principles of Mineral Processing. Littleton, CO Society for Mining, Metallurgy, and Exploration, Inc. Examines all aspects of minerals processing from the handling of raw materials to separation strategies to the remediation of waste products. The book relates recent developments in engineering, chemistry, computer science, and environmental science to explain how these disciplines contribute to the production of minerals and metals efficiently and economically from ores. 

This section provides an overview of the engineering technologies and applications that are currently applicable to the study and remediation of releases of hazardous wastes and constituents from RCRA (Resource Conservation and Recovery Act) facilities and those sites which parallel Superfund sites. Activities which would be termed removal actions or expedited response actions under CERCLA (Comprehensive Environmental Recovery-Cleanup and Liability Act) are also covered in this section. Information presented in this section represent excerpts from document EPA/625/4-89/020 (September 1989). 

Personnel and equipment need to be decontaminated in the CRZ. However, the CRZ might be a small area immediately adjacent to the remediation area, which workers are aware of, and is also marked appropriately. Although the CRZ is less formal and likely does not have many decontamination stations, efforts should be made to make sure that personnel and equipment are appropriately cleaned. Many times, due to the logistics of a smaller job, disposal of wastes becomes difficult. If purge water is drummed and left on the site, it is imperative that it is identified, labeled properly, recorded in the site log, and disposed of in the proper manner (in accordance with applicable, local, state, federal, or other regulations). 

Tlie Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980 was tire first major response to tire problem of abandoned hazardous waste sites throughout the nation. CERCLA was the begiiming of tlie remediation of hazardous waste sites. This program was designed to ... 

RCRA formed teclmical assistance panels and called for tlie research, development, demonstration, and evaluation of teclmologies for recycling and resource recovery. CERCLA was the begimiing of the remediation of Imztirdous waste sites. 

One of the most important elements in the remediation of existing waste sites is early detection and actiom As an example, the cost of cleanup at Stringfellow, California, increased from an estimated 3.4 million to 65 million because of pollutant dispersal during a decade of inaction after the first identification of the problem. The opportunities for innovative sampling strategies responsive to this need are discussed in the following section. 

To express that it is not just the amount of waste but rather its environmental impact, Sheldon introduced the environmental quotient EQ as the E factor multiplied by an unfriendliness quotient, Q, which can be assigned a value to indicate how undesirable a byproduct is. For example, Q = 0 for clean water, 1 for a benign salt, NaCl, and 100-1000 for toxic compounds. Evidently, catalytic routes that avoid waste formation are highly desirable, and the more economic value that is placed on, for example, the unfriendliness quotient, the higher the motivation to work on catalytic alternatives. Waste prevention is much to be preferred over waste remediation. 

This was previously used as a herbicide, and attention has been directed to its degradation in storage areas or where it has been spilled. A strain of Clostridium bifermentans KMR-1 (that is protected by a U.S. patent) was unable to use dinoseb as carbon or energy source. In the presence of a starch extract, however, a low level of transformation was observed, and the products could subsequently be mineralized by aerobic bacteria (Hammill and Crawford 1996). These observations have been extended to the remediation of soil slurries from a contaminated site by adding phosphate and starch waste that achieved anaerobic conditions, and inoculation with a culture from a pilot-scale... 

The process can handle a wide range of materials, including heavy metal contaminated wastes. It is very fast compared to conventional processes and produces an easily handled product that can be used in construction. Waste CO2 can be captured and converted into carbonate to yield carbon credits. Target applications include pre-treatment of waste prior to disposal, recychng and reuse of industrial waste, and remediation of contaminated brownfield sites. 

Soil Cleanup, or remediation, of hazardous waste sites will often produce contaminated soil. Contaminated soil must be handled as hazardous waste if it contains a listed hazardous waste or if it exhibits a characteristic of hazardous waste. As with hazardous waste, land disposal of hazardous soil is prohibited until the soil has been treated to meet LDR standards. These contaminated soils, due to either their large volume or unique properties, are not always amenable to the waste codespecific treatment standards. Because of this, U.S. EPA promulgated alternative soil treatment standards in 268.49 in May 1998. The alternative soil treatment standards mandate reduction of hazardous constituents in the soil by 90% or 10 times UTS, whichever is higher. Removal of the characteristic is also required if the soil is ignitable, corrosive, or reactive. 

In 1980, Congress passed the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). Commonly known as Superfund, the program under this law is focused on the remediation of abandoned or uncontrolled hazardous waste sites. Since 1980, Superfund has assessed nearly 44,400 sites. To date, 33,100 sites have been removed from the Superfund inventory to aid their economic redevelopment, and 11,300 sites remain active with the site assessment program or are included in the National Priorities List (NPL) for the implementation of remedial actions. By September 2000, 1509 sites were included in the NPL with ongoing or completed cleanup activities. 

Preliminary assessments have been conducted at more than 31,000 sites reported as possible sources of contamination. In 1990 there were over 1100 sites (presenting the greatest health risk and hence eligible for Superfund reimbursement) on the NPL.8-9 The NCP has outlined the level of cleanup necessary at Superfund sites and established the basic procedures that have to be followed for the discovery, notification, response, and remediation of the hazardous waste sites.10... 

Fugitive dusts are caused by wind erosion on waste sites, by vehicular traffic, and by excavation of waste during remedial action. The most commonly used control methods include the following ... 

NJ DEP, Underground Storage Tanks (USTs), Site Remediation and Waste Management, NJ Department of Environmental Protection, Trenton, NJ, November 2006. 

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