Environment remediation

Food and Agriculture Organization of the United Nations (FAO). Livestock a Major Threat to the Environment Remedies Urgently Needed. Retrieved from http // www.fao.org/newsroom/en/news/2006/ 1000448/index.html. 2006. 

Because of the highly unselective reactions involved in the photocatalytic processes, these have been widely studied in environment remediation, in which organic and inorganic pollutants in hquid and gas phases are totally degraded to innocuous substances. 

Environment—Remedial measures related to the enhancement of the environment in which the work under analysis is undertaken... 

The oxidation state of contaminants, such as U and Cr, dictate their fate and transport within the environments. The mobility and, hence, risk associated with U(VI) and Cr(VI) decreases upon reduction due to increased adsorption and precipitation capacity of their reduced states. The fate of each element will depend on the kinetics and thermodynamics of microbial and chemical processes within soils. By impeding the spread of contaminants in the environment, remediation strategies can focus on source areas thereby accelerating clean-up activities at reduced effort and cost. Moreover, enhancing our knowledge of redox processes will improve modeling efforts aimed at predicting the fate of contaminants in surface and subsurface environments. 

Risk management culture, where an engineering view of human error causation is dominant. Errors and accidents are analysed in terms of mismatches between the operator and his environment. Remedial actions typically include design changes and provisions of procedural support. 

For the sake of environment remediation, the procedures that decrease pollutant emissions or those that enable the elimination of pollutants already discharged into the environment are still of the highest interest. For that purposes, physical (filtration, adsorption), chemical (oxidation, catalytic conversions, ozonization in the presence of a catalyst or without one) or biological methods are available. The choice of particular method depends on the nature and the concentration of pollutant, and on its physical state. AU mentioned processes are permanently objects of further development. 

Preventive Measures. The intake uptake biokinetic model (lUBK) projects the impact of lead in the environment on blood lead. This model assumes conservatively high levels of intake and cannot account for chemical speciation, thus over-predictions of blood lead levels often occur. Nonetheless, because of the allegations of the impact of blood lead and neurobehavioral development, blood lead levels in children are being reduced adrninistratively to below 10 //g/dL. In order to do so, soil leads are being reduced to a level of between 500—1000 ppm where remediation is required. 

Two approaches exist to gain control of this factor altering the environment and isolating the metal from the environment. These are remedial measures and can be implemented during or after installation of the equipment. 

The options themselves invoke different controls and philosophies. The main techniques may be categorized according to whether they deal with the nutrients directly, or whether they interfere with the physical growth environment, or whether they invoke some form of biological remediation. 

Cleanup actions taken to deal with a release or threat of release of a hazardous substance that could affect humans and/or the environment. The term "cleanup" is sometimes used interchangeably with the terms remedial action, removal action, response action, or corrective action. 

The technical differences between site problems at RCRA facilities and CERCLA sites sometimes may be difficult to distinguish, owing to similarities in present or past uses of the site, in hydrogeologic setting, and/or in the types of substances disposed, spilled, or otherwise managed at the site. Consequently, many technical aspects of the study and remediation of releases of hazardous wastes and constituents from RCRA facilities often will closely parallel those at Superfund sites, and cleanups under both statutes must achieve similar goals for protection of public health and the environment. Additionally, activities which would be termed removal actions or expedited response actions under CERCLA may be undertaken by owners and operators under RCRA. In the RCRA context, such actions are termed interim measures, as will be discussed in subsequent chapters. 

As with alloys of other metals, nickel alloys may suffer stress-corrosion cracking in certain corrosive environments, although the number of alloy environment combinations in which nickel alloys have been reported to undergo cracking is relatively small. In addition, intergranular attack due to grain boundary precipitates may be intensified by tensile stress in the metal in certain environments and develop into cracking. Table 4.28 lists the major circumstances in which stress corrosion or stress-assisted corrosion of nickel and its alloys have been recorded in service and also shows the preventive and remedial measures that have been adopted, usually with success, in each case. 

Half-lives span a very wide range (Table 17.5). Consider strontium-90, for which the half-life is 28 a. This nuclide is present in nuclear fallout, the fine dust that settles from clouds of airborne particles after the explosion of a nuclear bomb, and may also be present in the accidental release of radioactive materials into the air. Because it is chemically very similar to calcium, strontium may accompany that element through the environment and become incorporated into bones once there, it continues to emit radiation for many years. About 10 half-lives (for strontium-90, 280 a) must pass before the activity of a sample has fallen to 1/1000 of its initial value. Iodine-131, which was released in the accidental fire at the Chernobyl nuclear power plant, has a half-life of only 8.05 d, but it accumulates in the thyroid gland. Several cases of thyroid cancer have been linked to iodine-131 exposure from the accident. Plutonium-239 has a half-life of 24 ka (24000 years). Consequently, very long term storage facilities are required for plutonium waste, and land contaminated with plutonium cannot be inhabited again for thousands of years without expensive remediation efforts. 

Cho T-H, Wild JR, Connelly KC. 2000. Utility of organophosphorus hydrolase for the remediation of mutagenicity of methyl parathion. Environ Toxicol Chem 19(8) 2022-2028. 

He is a recognized expert in solid state and materials chemistry and environmental chemistry. He has active programs in solid state f-element chemistry and nanomaterials science. His current research interests include heavy metal detection and remediation in aqueous environments, ferroelectric nanomaterials, actinide and rare-earth metal sohd slate chemistry, and nuclear non-proliferation. He currently maintains a collaboration in nuclear materials with Los Alamos National Laboratory and a collaboration in peaceful materials science development with the Russian Federal Nuclear Center - VNIIEF, Sarov, Russia, U.S. State Department projects. He has published over 100 peer-reviewed journal articles, book chapters, and reviews, while presenting over 130 international and national invited lectures on his area of chemistry. Dr. Dorhout currently serves as Vice Provost for Graduate Studies and Assistant Vice President for research. He has also served as the Interim Executive Director for the Office of International Programs and as Associate Dean for Research and Graduate Education for the College of Natural Sciences at Colorado State University. 

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. 

Lagadec AJM, DJ Miller, AV Lilke, SB Hawthorne (2000) Pilot-scale subcritical water remediation of polycyclic aromatic hydrocarbon- and pesticide-contaminated soil. Environ Sci Technol 34 1542-1548. 

Hamby DM (1996) Site remediation techniques supporting environmental restoration activities—a review. Sci Tot Environ 191 203-224. 

Ho SV et al. (1999) The lasagna technology for in situ soil remediation. 2. Large field test. Environ Sci Technol 33 1092-1099. 

Iben lET et al. (1996) Thermal blanket for in-situ remediation of surficial contamination a pilot test. Environ Sci Technol 30 3144-3154. 

---