Heavy metal compounds poisoning with

Several uranium compounds tested on the eyes of animals caused severe eye damage as well as systemic poisoning. The anion and its hydrolysis products determine the degree of injury. A hot nitric acid solution of uranyl nitrate spilled on the skin caused skin burns, nephritis, and heavy metal encephalopathy. Prolonged skin contact with uranium com-... 

Other factors indicated m the data of Tables 1 and 2 include Pour Point—defined as the lowest temperature at which the material will pour and a function of the composition of the oil in terms of waxiness and bitumen content Salt Content—which is not confined to sodium chloride, but usually is interpreted in terms of NaCl Salt is undesirable because of the tendency to obstruct fluid flow, to accumulate as an undesirable constituent of residual oils and asphalts, and a tendency of certain salt compounds to decompose when heated, causing corrosion of refining equipment Metals Content—heavy metals, such as vanadium, nickel, and iron, tend to accumulate in the heavier gas oil and residuum fractions where the metals may interfere with refining operations, particularly by poisoning catalysts. The heavy metals also contribute to the formation of deposits on heated surfaces in furnaces and boiler fireboxes, leading to permanent failure of equrpment, interference with heat-transfer efficiency, and increased maintenance. 

Antimony Potassium Tartrate This drug is not compatible with acids, alkalis, albumin, soap, salts of heavy metals, or tannins. Poisoning with antimony compounds resembles arsenic poisoning. Treatment is similar dimercaprol may be of use in treatment. 

Sulfur oxides (S02 and S03) present in flue gases from upstream combustion operations adsorb onto the catalyst surface and in many cases form inactive metal sulfates. It is the presence of sulfur compounds in petroleum-based fuels that prevent the super-sensitive base metal catalysts (i.e., Cu, Ni, Co, etc.) from being used as the primary catalytic components for many environmental applications. Precious metals are inhibited by sulfur and lose some activity but usually reach a lower but steady state activity. Furthermore the precious metals are reversibly poisoned by sulfur compounds and can be regenerated simply by removing the poison from the gas stream. Heavy metals such as Pb, Hg, As, etc. alloy with precious metals and permanently deactivate them. Basic compounds such as NH3 can deactivate an acidic catalyst such as a zeolite by adsorbing and neutralizing the acid sites. 

Maxted classified from a large body of experiments the poisons for metallic catalysts into three classes of substance (1) the compounds of groups VA and VIA (or groups 15 and 16) elements with at least one unshielded electron pair (2) heavy metal and metal ions possessing the outer d shells, each of which is occupied entirely by at... 

Bismuth and its compounds do not appear to have been responsible for poisoning associated with work, so it is looked upon as the least toxic of the heavy metals currently used in industry. Bismuth and bismuth oxide are poorly soluble in blood plasma and fairly rapidly eliminated by the urinary tract. As the reported number of cases is small and adequate follow-up studies have not yet been completed, it is difficult to generalize the toxicity of bismuth compounds. So far, no strict limits appear to have been set for bismuth in air and drainage in industrialized countries. 

All heavy crude oil residues have heavy metals such as Ni, V or Fe in their structure. These metals are bonded as organometalic compounds. At high temperatures and for hydrogenation reactions, these compounds are cracked and heavy metals are deposited on the catalyst surface. These metals can also react with hydrogen sulfur from the gas phase to form metal sulfides. The deposition of sulfides of iron, vanadium or nickel leads to irreversible poisoning of the catalyst. This is the difference between catalyst deactivation by metals and deactivation by coke the former leads to an irreversible loss of the catalyst activity. 

D-penicillamine (D-3-mercaptovaline, Cuprimine), a breakdown product of penicillin, was, after the discovery of its chelating properties of copper ion (Fig. 2-6), introduced as an antidote to copper poisoning. It was also found useful in the treatment of Wilson s disease, where excess copper accumulation causes liver cell damage. Heavy metal poisoning treatment is not limited to copper. Mercury and lead poisoning are also successfully reversed. Formation of cysteine calculi (cystinuria) can also be reversed with penicillamine by forming a soluble disulfide compound. 

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