Metal scavengers

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Heavy metals are also present in the environment, having been introduced through several industrial processes [4]. Their presence in excess can be harmful to humans and can have a negative impact on the environment. Heavy metals are non-degradable, and so they are accumulated in the environment, [5, 6] mostly through industrial wastes. Since the accumulation of many toxic chemicals 

The Power of Functional Resins in Organic Synthesis. Judit Tulla-Puche and Fernando Albericio 

Copyright 2008 WILEY-VCH Verlag GmbH Co. KGaA, Weinheim ISBN 978-3-527-31936-7 

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Honeyman BD, Balistrieri LS, Murray JW (1988) Oceanic trace metal scavenging the importance of particle concentration. Deep-Sea Res 35(2) 227-246... 

Homogeneity/Heterogeneity via Application of Insoluble Metal Scavengers Application to Heck... 

Some of these particles eventually sink to the seafloor, thus removing metals from the ocean. This process of surface adsorption followed by settling is referred to as particle scavenging. The rate and degree to which a dissolved metal is scavenged from the ocean depends on (1) its elemental nature, (2) the abimdance of particulate matter, (3) the concentrations of other solutes that can compete fc>r adsorption sites, and (4) the depth of the water column. Metal scavenging rates have been inferred from the concentrations of naturally occurring radionuclides, such as " Th, Th, and Th. 

For some metals, scavenging is reversible, making the trip down to the sediments a stepwise process in which metals are desorbed for short periods before hitching another... 

Soil anomalies present in the raw element data from a variety of extractions are attributed to the effects of metal scavenging onto the surfaces of either Fe oxides or humic/fulvic acids. These metal... 

Cracking Metal-Contaminated Oils with Catalysts Containing Metal Scavengers... 

Recently, it has been reported in the patent literature that vanadium (and nickel) resistance in a FCC can be significantly enhanced by the addition of certain diluents capable of acting as metal scavengers (1-4). In fact, addition of alumina and... 

Figure 4. Preservation of cracking activity by metal scavengers.

Figure 5. The effects of vanadium on a cracking catalyst activity before and after addition of a metal scavenger (Spanish sepiolite).

Occelli, M. L. and Stencel, J. M., "Cracking Metals-Contaminated Oils with Catalysts Containing Metal Scavengers. Part II. The Effect of Aluminuma Particles Addition on Vanadium Passivation." (In preparation)... 

The relative ease with which VpOr can be reduced to V(III) in aluminosilicates indicate the exiirence of weak metal-surface interactions and the inability of the surface to effectively passivate vanadium. Similarly, V on Kaolin (and metakaolin) exist mostly as the "free oxide and can (in part) be reduced to V(III) species. Therefore, DFCC systems containing metakaolin microspheres (or amorphous aluminosilicates (15)) should not be as effective as sepiolite in passivating metals TTke Ni and V. In fact, DCC mixtures loaded with 5000 ppm Ni-equivalents (that is 0.6% V + 0.38% Ni) are not metals resistant when metakaolin is used as a metals scavenger (1) ... 

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