Contaminants in water

A.dsorption. Biomass, often agricultural by-products, has been widely used as an adsorbent for metals and other contaminants in water (78), but this is outside the scope of this article. 

Hot corrosion is a rapid form of attack that is generally associated with alkali metal contaminants, such as sodium and potassium, reacting with sulfur in the fuel to form molten sulfates. The presence of only a few parts per million (ppm) of such contaminants in the fuel, or equivalent in the air, is sufficient to cause this corrosion. Sodium can be introduced in a number of ways, such as salt water in liquid fuel, through the turbine air inlet at sites near salt water or other contaminated areas, or as contaminants in water/steam injections. Besides the alkali metals such as sodium and potassium, other chemical elements can influence or cause corrosion on bucketing. Notable in this connection are vanadium, primarily found in crude and residual oils. 

In contrast, in developing countries published information on this topic is scarce, though existing information indicates that rain levels above background values also increase the amoimts of indicators in fresh water bodies. Blum et al. [32] described in Nigeria a peak period of faecal pollution of water sources in the transition between the dry and the wet seasons. Gasana et al. [33] described boosts of faecal contaminants in water supplies in Rwanda after heavy rain episodes. 

Anipsitakis GP, DD Dionysiou (2003) Degradation of organic contaminants in water with sulfate radicals generated by the conjunction of peroxymonosulfate with cobalt. Environ Sci Technol 37 4790-4897. 

With the recent Increase In activity at hazardous waste sites where cleanup and remedial action are underway, there has emerged a need for rapid analytical methods for assessing contamination in water, sediment, and soil. Of special Interest, because of widespread use and disposal. Is the group of materials known as PCB s (polychlorinated biphenyls). 

Sinton,L. W. Finlay, R. K. FIannah,D. J. Distinguishing human from animal faecal contamination in water A review. New Zealand J. Mar. Freshw. Res. 1998,32,323-348. 

Hariharan, C. (2006) Photocatalytic degradation of organic contaminants in water by ZnO nanoparticles revisited. Applied Catalysis A General, 304, 55-61. 

The studies realized within the frame of the AquaTerra project have involved a great number of researchers from different disciplines. In this chapter, the ones concerning organic contamination in water, sediments and aquatic biota have been... 

Said TO, El Moselhy KM, Rashad AAM et al (2008) Organochlorine contaminants in water, sediment and fish of Lake Burullus, Egyptian Mediterranean Sea. Bull Environ Contam Toxicol 81 136-146... 

Fernandez, M., M. Ibanez, Y. Pico, and J. Manes. 1998. Spatial and temporal trends of paraquat, diquat, and difenzoquat contamination in water from marsh areas of the Valencian community (Spain). Arch. Environ. Contam. Toxicol. 35 377-384. 

Biochemical Oxygen Demand A numerical estimate of contamination in water expressed in milligrams per liter of dissolved oxygen. A measure of the amount of oxygen consumed in biological processes that break down organic matter in water. 

The study of obsidian by NAA has proved to be particularly fruitful because of the relatively limited number of sources and the extent to which it was traded (Beardsley et al. 1996, Cook 1995, Darling and Hayashida 1995, Kuzmin et al. 2002, Leach 1996). Studies have also extended to include other volcanic materials such as pumice (Bichler et al. 1997, Peltz et al. 1999). NAA has also been used for the analysis of flint as OES is insensitive and not reproducible due to the effect of the high silica content, and AAS requires significant sample preparation (Aspinall and Feather 1972). The wide range of appropriate materials extends to organic materials such as human bone (Farnum et al. 1995), and its exceptional sensitivity to trace elements has led to its wide use in geochemistry (for example in determining trace [ppb] contaminants in waters) and more recently in forensic chemistry. 

Another pre-treatment often used to prevent biological degradation of organic contaminants in water is acidification with sulfuric acid to pH <3 [4], The change in concentrations of NPEO, AEOs and PEGs in spiked groundwater (500 p,gL 1) and in wastewater treatment plant (WWTP) influent preserved by addition of formaline (1 and 3%, v/v) and by acidification to pH 3 with sulfuric acid and kept for 30 days at 4°C are shown in Table 4.4.1. 

Hoffmann, M. R. Hua, I. Hoechemer, R., Application of Ultrasonic Irradiation for the Degradation of Chemical Contaminants in Water, Ultrasonics Sonochemistry, 3(3), pp. S163-S172, 1996. 

Allan RJ, Ball AJ. 1990. An overview of toxic contaminants in water and sediments of the Great Lakes Part I. Water Pollution Research Journal of Canada 25(4) 387-505. 

SnC>2 nanoparticles have been successfully synthesized by chemical co-precipitation method using ethanol, acetone, tetrahydrofuran (THF) and ether as solvents. X-ray Diffraction (XRD), Field Emission Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM) have been used to study the crystallographic and morphological properties of synthesized SnC>2 nanoparticles, while their optical properties have been studied by UV-Visible absorption spectroscopy. UV-Vis absorption spectra shows a weak quantum confinement in all the synthesized SnCL samples. The photo-catalytic activity of as-synthesized SnC>2 nanoparticles under UV irradiation has been evaluated using Methylene Blue (MB) dye as a test contaminant in water. The results showed that solvents played a key role to control the morphology and photo-catalytic activity of SnCE nanoparticles. 

Huckins, J.N. 1989, A Novel Approach for Monitoring and Subsequent Cleanup of Nonpolar Contaminants in Water. The 103 Association of Official Analytical Chemists Annual International Meeting St. Loiris, MO. Abstract 327. 

Huckins, J.N. Manuweera, G.K. Petty, J.D. Mackay, D. Lebo, J.A. 1993, Lipid-containing semipermeable membrane devices for monitoring organic contaminants in water. Environ. Sci. Technol. 27 2489-2496. 

Johnson, B.T. Petty, J.D. Huckins, J.N. 2000, Collection and detection of lipophilic chemical contaminants in water, sediment, soil, and air. Environ. Toxicol. 15 248-252. 

Metcalfe, T.L. Metcalfe, C.D. Bennett, E.R. Haffner, G.D. 2000, Distribution of toxic organic contaminants in water and sediments in the Detroit River. J. Great Lakes Res. 26 55-64. 

Table 8.3. Analytical Methods for the Analysis of Contaminants in Water...

In order to achieve complete destruction of biological contaminants in water through sonication very high ultrasonic intensities are necessary. Unfortunately this makes the technique expensive to use for general microbiological decontamination. However over the last two decades some conventional disinfection techniques involving chemicals, ultraviolet light and heat treatment have become less effective as some bacteria become more resistant. Such processes have become a focus for the use of sonication as an adjunct to other techniques. 

Huang CH, Renew JE, Smeby KL, Pinkerston K, Sedlak DL (2001) Assessment of potential antibiotic contaminants in water and preliminary occurrence analysis. Water Resour Update 120 30-40... 

Roehl R, Slingsby R, Avdalovic N, Jackson PE (2002) Applications of ion chromatography with electrospray mass spectrometric detection to the determination of environmental contaminants in water. J Chromatogr A 956(l-2) 245-254... 

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