Heavy metals from environmental

Giokas, D. L. Paleologos, E. K. Karayannis, M. I. Micelle-Mediated Extraction of Heavy Metals from Environmental Samples An Environmental Green Chemistry Laboratory Experiment, J. Chem. Educ. 2003, 80, 61-64. 

There are many review articles concerning application of USE in food technology [57] and for isolation of bioactive substances from herbs and other plant materials [58], as well as leaching of heavy metals from environmental and industrial samples [59]. Application of ultrasound during sequential extraction of trace elements significantly shortens the whole procedure however, for satisfactory efficiency it is necessary to increase the temperature and modify the matrix. 

Ultrasonic extraction is an effective method for the extraction of a number of heavy metals from environmental and industrial hygiene samples. In many cases, it provides a means for quantitative recovery of metals and replacing drastic preparation procedures requiring the use of concentrated acids and the application of high heat and/or pressures (i.e. hot plate and/or microwave extraction). 

Landsberger S and Wu D (1995) The impact of heavy metals from environmental tobacco smoke on indoor air quality as determined by Compton suppression neutron activation analysis. Sd Total Environ 173/174 323-337. 

DYNAMIC LEACHING OF ENVIRONMENTALLY RELEVANT FORMS OF HEAVY METALS FROM SOILS... 

Dushenkov, V., Kumar, N.P.B. A., Motto, H., and Raskin, I., Rhizofiltration The use of plants to remove heavy metals from aqueous streams, Environmental Science and Technology, 29, 1239-1245, 1995. 

Hussein, H., Ibrahim, S.F., Kandeel, K., and Moawad, H., Biosorption of heavy metals from wastewater using Pseudomonas sp., Environmental Biotechnology, 7 (1), 2004. 

Gale, N.L., E. Bolter, and B.G. Wixson. 1976. Investigation of Clearwater Lake as a potential sink for heavy metals from lead mining in southeast Missouri. Pages 95-106 in D.D. Hemphill (ed.). Trace Substances in Environmental Health. Vol. X. Univ. Missouri, Columbia. 

Ultrasonically assisted extraction is particularly useful for the environmental analytical chemist because it facilitates a more complete extraction of absorbed chemicals e. g. the extraction of pesticides [57, 58] and of heavy metals from soils [59[. 

Environmental Research and Development, Inc., offers the neutral process, which reduces hex-avalent chromium using sulfide catalyzed by ferrous iron, while precipitating heavy metals at pH ranges from 7.4 to 8.4. The vendor has combined this technology with cross-flow microfiltration to remove heavy metals from contaminated groundwater and wastewater without the need for large clarifiers. The technology has been used at U.S. Department of Defense (DOD) sites and is commercially available. 

The Unipnre Environmental, Unipnre process technology is a unique iron co-precipitation method for removal of heavy metals from waste streams or groundwater. It can act as a primary metal-removal system or as a polishing step to an existing treatment system. The reactor mod-nle replaces the nentrahzation tank in a conventional wastewater treatment system. The process prodnces solids that are extremely insolnble in water and mild acid solutions. 

Adsorption, ion exchange, and catalysis share a great portion of environmental applications, as shown in the next section, and more extensively, in Chapter 2. Specifically, adsorption and catalysis are extensively used for the removal or destruction of air pollutants in gas streams as well as for purifying wastewaters or fresh water. Ion exchange has a special position among other techniques in the removal of heavy metals from wastewater. 

Walker, S. G., Flemming, C.A., Ferris, F.G., Beveridge, T.J. Bailey, G. W. (1989). Physiochemical interaction of Escherichia coli cell envelopes and Bacillus subtilis cell walls with two clays and ability of the composite to immobilize heavy metals from solution. Applied and Environmental Microbiology, 55, 2976-84. 

Krishnan, E. R. August 1983. "Recovery of Heavy Metals From Steelmaking Dust." Environmental Progress. Vol. 2, No. 3. 

Environmental Impact. Methylene chloride is nonphotochemically reactive and is not listed as an ozone (qv) depleler. Methylene chloride removers can easily be recovered from paint chips and other residue sedimentation, tlius allowing recovery of remover and its continued use. Tins greatly increases the useful life of the remover and, when mixed with fresh remover, eluninates the need for disposing of the used remover. This process requires no special recovery equipment. The high volatility of methylene chloride allows the waste residue from the stripping process to be easily dried, The resulting waste is normally considered hazardous because of the amounts of heavy metals from old finishes. 

Pamukcu, S., and Wittle, J. K., (1992). Electrokinetic removal of selected heavy metals from soil. Environmental Progress, 11(3), 241-250. 

There has been great concern about how heavy metals affect environmental quality. Heavy metals (As, Cu, Cd, Cr, Pb, Hg, and Ag) come from a number of different sources, including industrial sources, domestic water supplies, residential wastewater, surface runoff, atmospheric... 

In the last five decades an intensive anthropogenic load on the marine environment in the Sebastopol region has led to a sharp decline in the environmental situation. This process was spurred by construction here of the main Navy base of the Black Sea Fleet and although recently the quantity of pollutants getting into the Sebastopol bay has somewhat diminished (in 1996-2000 heavy metals from 203.7 tons to 68.3 tons, hydrocarbons from 292.6 to 206.3 tons), the general condition of the Sebastopol bays (and there are 19 of them) [7] is evaluated as critical. 

The high affinity of 1 for some transition elements suggests the possibility of using it for selective removal of toxic heavy metals from contaminated environmental systems and biological liquors. This point is illustrated by the uptake of Pb, Cu ", Cd " and Hg ions in groundwater simulant (Fig. 7a) and Cu and Cd ions uptake in the Ringer solution (Fig. 7b). 

Ultrasonic extraction is especially efficient with environmental and industrial hygiene samples however, in addition to the inapplicability to the extraction of some metals and the inability to quantitatively extract heavy metals from very large bulk environmental samples [14,15], ultrasounds occasionally produce ionic species that were absent from the original sample. The new species give unidentified signals that yield spurious analytical results such is the case with the extraction of ionic species from airborne particulate matter [23], where the new ions formed prevent accurate determination of those initially present in the sample. 

A. Mdller, A. Grahn, and U. Welander, Precipitation of Heavy Metals from Landfill Leachates by Microbially Produced Sulphide, Environmental Technology, 25(1), 69-77 (2004). 

In the field of environmental engineering, electro-osmotic dewatering can be used to remove organic contaminants or toxic heavy metals from... 

An environmental application of liquid extraction is the removal of trace organics from water. Examples are the separation of acetic acid-water mixtures and removal of solvents, insecticides, pesticides, etc., from water. It can also be applied to the separation of liquids with close boiling points or those that form azeotropes, such that distillation is not useful. In addition, zero- or low-volatility compounds, such as metals and organometallic derivatives, can be separated by liquid extraction as can mixtures of water-hydrogen bonded compounds, such as formaldehyde. Solid extraction (leaching) can be used to remove organics or heavy metals from contaminated soils, sludges or contaminated equipment. 

A very important practical and environmentally beneficial aspect of the use of a separate aqueous phase in catalytic reactions producing water-insoluble products is the potential for relatively easy and complete recovery of water-soluble catalysts. This could lead to the elimination of further steps for removal of traces of heavy metal from the product and to considerable savings. ... 

Pytoremediation is an intriguing process for the biologically promoted removal of heavy metals from both polluted soils and wastewater. Phytoremediation is broadly defined as the use of living green plants to remove, contain, or render harmless environmental contaminants. Phytoremediation processes are capable of removing heavy metals directly from soil or water. Phytoextraction is the use of plants to remove heavy metals from aqueous streams. 

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