Critical metal pollutant

The geochemical fate of most reactive substances (trace metals, pollutants) is controlled by the reaction of solutes with solid surfaces. Simple chemical models for the residence time of reactive elements in oceans, lakes, sediment, and soil systems are based on the partitioning of chemical species between the aqueous solution and the particle surface. The rates of processes involved in precipitation (heterogeneous nucleation, crystal growth) and dissolution of mineral phases, of importance in the weathering of rocks, in the formation of soils, and sediment diagenesis, are critically dependent on surface species and their structural identity. 

U. Forstner, G. Muller, Schwermetalle in Fliissen und Seen, Springer, Berlin, 1974 C. F. Baes, jr., R. Mesmer, The Hydrolysis of Cations, Wiley, New York, 1976 R. M. Smith, A. E. Martell, Critical Stability Constants, Plenum Press, New York, 1976 P. Benes, V. Majer, Trace Qiemistry in Aqueous Solutions, Elsevier, Amsterdam, 1980 M. C. Kavanough, J. O. Leclde, Particulates in Water, Amer. Chem. Soc. Adv. Chem. Series 2SP, Amer. Chem. Soc. Washington, DC, 1980 W. Stumni, J. J. Morgan, Aquatic Chemistry, 2nd ed., Wiley, New York, 1981 U. Forstner, G. T. W. Wittmaim, Metal Pollution in the Aquatic Environment, 2nd ed.. Springer, Berlin, 1981... 

Processes that depend critically on these phenomena include energy storage and conversion, corrosion and corrosion control, membrane separations, deposition and etching by electrolytic and plasma processes, electrosynthesis of organic and inorganic chemicals, production and refining of metals, pollution detoxification and recovery, desalination, and many others. 

This chapter deals with a method of retrospective hiomonitoring of trace metal pollution using chemical analyses of tree rings, known as dendroanalysis. The usefulness of dendroanalytical results is disputed (Hagemeyer, 1993). Experimental tests of the method are presented and its applicability is critically examined. Furthermore, prospects for future studies of trace metals in trees are outlined. 

Hagemeyer, J., 1993. Monitoring trace metal pollution with tree rings a critical reassessment. In Markert, B. (Ed.), Plants as Biomonitors. Verlag Chemie, Weinheim, pp. 541-563. 

Metal pollution not only affects humans but also impacts on the entire ecological system. In the Arctic, reindeer and caribou have been documented to be accumulating Cd which has been linked to kidney dysfunction (AMAP 1997), while filter feeders, such as mussels, have also been shown to accumulate toxic metals such as Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn (Mubiana et al. 2005). Mercury has been found to be bio-concentrating at critical levels in the marine environment, with higher concentrations documented in predatory fish and in marine mammals such as ringed seals (AMAP 1997). This has resulted in subsequent bioaccumulation in human populations who consume large amounts of fish, such as the populations of the Faroe Islands in the Northern Atlantic, Maderia off the west coast of North Africa and the Inuit people of northern Canada (Grandjean et al. 1992 Renzoni et al. 1998 Wheatley et al. 1979). 

Although the petrochemical and metals industries were the primai y focus of the toxic air pollutants legislation, approximately forty of these substances have been detected in fossil power plant flue gas. Mercury, which is found in trace amounts in fossil fuels such as coal and oil, is liberated during the combustion process and these emissions may be regulated in the future. EPA issued an Information Collection Request (ICR) that required all coal-fired plants to analyze their feed coal for mercury and chlorine. Since these data will be used in making a regulatory decision on mercury near the end ot the year 2000, it is critical that the power industry provide the most accurate data possible. 

Three-phase slurry reactors are commonly used in fine-chemical industries for the catalytic hydrogenation of organic substrates to a variety of products and intermediates (1-2). The most common types of catalysts are precious metals such as Pt and Pd supported on powdered carbon supports (3). The behavior of the gas-liquid-sluny reactors is affected by a complex interplay of multiple variables including the temperature, pressure, stirring rates, feed composition, etc. (1-2,4). Often these types of reactors are operated away from the optimal conditions due to the difficulty in identifying and optimizing the critical variables involved in the process. This not only leads to lost productivity but also increases the cost of down stream processing (purification), and pollution control (undesired by-products). 

Evstafyeva, E., Slusarenko, A. (2003). Heavy metals and immune status of the body for different age groups Proceedings 5th Subregional Meeting of ICPs and Training Workshop on the Calculation and Mapping of Critical Loads for Air Pollutants Relevant for UN/ECE Convention on LRTAP in East and South East European Countries. Minsk, pp. 37-39. 

Galiulin, R.F, Bashkin, V.N, Galiulina, R.R and Birch, P. (2001). A Critical Review Protection from Pollution by Heavy Metals — Phytoremediation of Industrial Wastewater. Land Contamination Reclamation, 9(4), 349-357... 

Priputina, I., Tankanag, A., Abramychev, A., Bashkin, V. (1999). Biogeochemical data used for estimation of critical loads of heavy metals on the ecosystems of East-European plain. // Calculations and mapping of critical loads for air pollutants relevant to the UN/ECE Convention on Long-range Transboundary Air Pollution. Proceedings of the Workshop at Pushchino, Sept. 27-Oct. 2,1999. Moscow. POLTEX. pp. 65-71. 

Baath, E. (1989). Effects of heavy metals in soil on microbial processes and populations (a review). Water, Air, and Soil Pollution, 47, 335—79-Babich, H. Stotzky, G. (1980). Environmental factors that influence the toxicity of heavy metal and gaseous pollutants to microorganisms. Critical Reviews in Microbiology, 8,99-145. Babich, H. Stotzky, G. (1985). Heavy metal toxicity to microbe-mediated ecologic... 

The AYRSSM allows us to estimate the dependence of pollution level in the AYRS estuary as a function of anthropogenic activity. Suppose that the intensity of sources of heavy metals is such that their concentration in the water near Angarsk, Irkutsk, Krasnoyarsk, Bratsk, and Ust-Ilimsk can be described by a stationary function, supporting heavy metal concentrations at level h at each of these cities. Computer experiments show that there is a stable correlation between h, the heavy metal concentration in the AYRS estuary, and the water flow rate fi. An increase in h of 10% leads to a rise of pollution input to the Kara Sea by 2.5%. An increase in h of 1% leads to a rise of pollution input to the Kara Sea by 0.7%. These results are correct only when variances in values fi and h are close to their average estimates. Near their critical values the estimates are unstable and more detailed models are required. 

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