Copper reactions with organic matter

Stevenson F.J., Fitch A. Reactions with organic matter . In Copper in Soils and Plants, J.F. Loneragan, A.D. Robson, R.D. Graham, eds. Sydney Academic Press. 1981. 

SAFETY PROFILE Poison by ingestion and intraperitoneal routes. A trace mineral added to animal feeds. Potentially explosive reaction with charcoal + ozone, metals (e.g., powdered aluminum, copper), arsenic carbon, phosphoms, sulfur, alkali metal hydrides, alkaline earth metal hydrides, antimony sulfide, arsenic sulfide, copper sulfide, tin sulfide, metal cyanides, metal thiocyanates, manganese dioxide, phosphorus. Violent reaction with organic matter. When heated to decomposition it emits very toxic fumes of I and K2O. See also lODATES. 

SAFETY PROFILE Moderately toxic by ingestion. A skin and eye irritant. Questionable carcinogen with experimental tumorigenic data. Mutation data reported. See also PEROXIDES, ORGANIC. Potentially explosive when heated above 115°C. Explosive reaction on contact with organic matter or copper(I) bromide -I-Hmonene. When heated to decomposition it emits acrid smoke and fumes. 

BORATO CALCICO (Spanish) (10102-75-7) A strong oxidizer. Violent reaction with combustible materials, reducing agents. Contact with strong acids forms hydrogen bromide. Incompatible with aluminum, ammonium salts, arsenic, carbon, copper, metal powder, organic matter, sulfides, sulfur, phosphorus. 

Equilibrium complexation constants for Cu reactions with natural organic matter and the details of Cu speciation are bound to remain somewhat uncertain, since the composition of the complexing molecules varies from site to site. What is not in dispute is that the fraction of dissolved copper present as free aquo Cu is probably very small in any natural water. In extremely pristine waters, hydroxide and carbonate complexes may dominate, but organic complexes usually dominate in waters containing more than a few tenths of a mg/L organic carbon. 

Lovgren, L. and Sjoberg, S. (1989) Equilibrium approaches to natural water systems - 7. Complexation reactions of copper (II), cadmium(II) and mercury(II) with dissolved organic matter in concentrated bog-water. Water Res., 23, 327-332. 

POTASSIUM lODATE (7758-05-6) KIO, Noncombustible solid but many chemical reactions can cause fire and explosions. A strong oxidizer. Reacts violently with many materials, including reducing agents, hydrides, nitrides, and sulfides combustible materials, organic substances, manganese dioxide, arsenic, finely divided metals or carbon materials, hydrides of alkali or alkaline earth metalss, metal cyanides, metal thiocyanates, phosphonium iodide, red phosphorus, sulfides, sulfur, xenon tetrafluoride. Forms explosive compounds with solid organic matter. Mixture of powdered aluminum forms heat-, friction-, and shock-sensitive explosive. Attacks chemically active metals (e.g, aluminum, copper, zinc, etc.). Thermal deconposition, at temperatures above 1040°F/560°C, releases toxic iodine fumes. 

CALCIUM lODATE (7789-80-2) A powerful oxidizer. Violent reaction with phospho-nium iodide, reducing agents, copper, aluminum. Forms sensitive explosive mixture with carbon dust, phosphorus, organic matter, powdered metals. Incompatible with arsenic, carbon, metal sulfides, sulfur. 

A mathematical model is formulated to describe the first-order kinetics of ionic copper released into a marine environment where sorption on suspended solids and complexation with dissolved organic matter occur. Reactions are followed in time until equilibrium, between the three copper states is achieved within about 3 hr (based on laboratory determinations of rate and equilibrium constants). The model is demonstrated by simulation of a hypothetical slug discharge of ionic copper, comparable to an actual accidental release off the California coast that caused an abalone kill. A two-dimensional finite element model, containing the copper submodel, was used to simulate the combined effects of advection, diffusion, and kinetic transformation for 6 hr following discharge of 45 kg of ionic copper. Results are shown graphically. 

Much emphasis has been placed in recent years on the use of chelates in supplying plants with iron, zinc, copper and manganese. Since chelation reactions are believed to be involved in the reaction of humus with these metal ions it is appropriate to consider what is meant by chelation and to compare the status of metals held in this manner with that of those held in the organic matter exchange complex. Incidentally, the formation of soluble metal—organic complexes has long been known although emphasized only comparatively recently (Horner et al., 1934). 

---