Remediation technology types

Identifying and screening the technologies applicable for each general response action to eliminate those that cannot be implemented technically at the site and to specify remedial technology types... 

Soil remediation technologies can be classified according to the type of treatment processes taking place5-7 ... 

METLCAP A process for encapsulating hazardous heavy metal wastes in a proprietary type of cement. Developed and offered by Environmental Remediation Technology, Cleveland, OH. 

Remediation is a process of restoration. In order to conduct remedial activities, we must first understand both the process which generated the contaminants, the contaminant chemistry, the soil geology, the site hydrology, and the nature and kind of interactions between the soil, water, and the contaminants. In this brief exposition, weTl discuss a couple of different types of sites and see the limits of remediation technology. 

This type of technology differs from most other remediation technologies is that the goal is to trap and immobilize contaminants within the existing medium, rather than trying to remove them via chemical or physical treatments. 

Acoustically enhanced remediation (AER) is an in situ remediation technology that uses acoustic excitation fields (AEFs) to enhance rates of fluid and contaminant extraction from a wide variety of soil types. Bench-scale proof-of-concept tests have been completed and were followed by larger scale laboratory experiments. According to the vendor, a field-scale proof-of-principle step has been planned. The vendor indicates that this technology is currently commercially available however, it is uncertain whether these field-scale tests have occurred. 

SOLVATEO ELECTRON TECHNOLOGY MULTI-MEDIA REMEDIATION UNIT Type SL "XH... 

Many industries thrive on environmental fears, such as companies featuring asbestos and radon remediation. This would also be the case of soil and other types of remediation technology-driven industries. 

Remedial Technologies and Associated Source Type Categories... 

Much has been learned about insulin because of its relationship with diabetes. In classical, type I diabetes (or insulin-dependent diabetes), the individual does not make insulin, or at least not enough of it. This is usually caused by destruction of the beta cells of the islets of Langerhans in the pancreas from a type of autoimmune disease. The only remedy for type I diabetes is regular insulin injections, and insulin is produced for this purpose by recombinant DNA technology (Chapter 13). 

T vo types of remediation activities are possible under CERCLA removal and remedial actions. Remedial actions are longer-term permanent solutions to hazardous waste contamination. Removal actions are short-term cleanup actions that address immediate threats at a site. They are conducted in response to an emergency situation (e.g. to avert an explosion, to clean up a hazardous waste spill, or to stabilize a site until a permanent solution can be found). Electrokinetic remediation technologies are likely to be part of a CERCLA remedial action. There are nine general criteria that must be addressed by those wishing to implement electrokinetic technologies as part of CERCLA remedial actions ... 

Electroreclamation (ER) is a soil remediation technology that uses electrokinetic effects to remove inorganic contamination. It can, for example, be used to remove heavy metals, all types of cyanides, arsenic, and other ionic or polar compounds. The basic principle involves applying a difference in potential, thus causing charged particles to migrate to the cathode or the anode. A special electrolyte system is used to both condition physical parameters around the electrodes and in the soil, and to remove the contaminants that have collected around the electrodes. 

Calculations at the 6-31G and 6-31G level provide, in many cases, quantitative results considerably superior to those at the lower STO-3G and 3-21G levels. Even these basis sets, however, have deficiencies that can only be remedied by going to triple zeta (6-31IG basis sets in HyperChem) or quadruple zeta, adding more than one set of polarization functions, adding f-type functions to heavy atoms and d-type functions to hydrogen, improving the basis function descriptions of inner shell electrons, etc. As technology improves, it will be possible to use more and more accurate basis sets. 

Table 2 is a slightly different view of the applicability of the remediation process. It is broadly divided into organic and inorganic contaminants, and considers the ease of applying a specific technology to a soil type. The categories and assumptions in Table 2 are very broad, and... 

In June of 1999, Edenspace Systems Corporation acquired Phytotech, Inc., a company specializing in phytoremediation technologies. Phytotech has developed several proprietary techniques for the phytoremediation of sites contaminated with heavy metals and radionuclides. Phytoremediation is an emerging bioremediation technology that uses plants to remediate contaminated media. Hyperaccumulation is a specific type of phytoremediation that can be used at sites contaminated by radionuclides and heavy metals. Hyperaccumulation may be defined as the ability... 

Electrokinetic remediation is limited by the type of contaminant, heterogeneities or anomalies in the soil, extreme pHs, pore water chemistry, lack of pore water, contaminant and noncontaminant ion concentrations, metals precipitation, and reduction-oxidation changes induced by the process electrode reactions. It may be difficult to estimate the time that will be required to remediate a site using this technology. Laboratory treatability testing may provide a false indication of the applicability of electrokinetic remediation at a specific site. Further research is required to determine the technology s limitations and ramifications. 

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