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Copper

DESIGNATIONS

CAS No.: 7440-50-8
Registry name: Copper
Chemical name: Copper
Synonyms, Trade names: Copper, cuprum
Chemical name (German): Kupfer
Chemical name (French): Cuivre
Appearance: ductile, soft metal with distinctive reddish colour

BASIC CHEMICAL AND PHYSICAL DATA

Chemical symbol: Cu
Rel. atomic mass: 63.55 g
Density: 8.9 g/cm3 at 20C
Boiling point: 2580C
Melting point: 1083C
Vapour pressure: 0 mbar at 20C, 0.073 Pa at 1083C, 0.133 Pa at 1870C
Solvolysis/solubility: the metal is only directly attacked by oxidising acids (nitric acid, hot concentrated sulphuric acid).

BASIC DATA OF SELECTED COMPOUNDS

CAS No: 7758-99-8 1317-39-1
Chemical name: Copper(II) sulphate pentahydrate Copper(I) oxide
Synonyms, Trade names: Bluestone, blue vitriol Copper oxide
Chemical name (German): Kupfersulfat - Pentahydrat Kupfer(I)-oxid, Kupferoxid
Chemical name (French): Sulfate de cuivre Oxyde de cuivre(I)
Appearance: light blue crystalline powder yellow to red crystalline powder depending on preparation and particle size
Empirical formula: CuSO4 5H2O Cu2O
Rel. molecular mass: 249.61 g 143.09 g
Density: 2.285 g/cm3 5.8-6.2 g/cm3
Boiling point: not distillable above 1800C decomposition
Melting point: decomposition (above 88C: subsequent elimination of water) 1235C
Vapour pressure: 0 Pa 0 Pa
Solvolysis/solubility: in water: 148 g/l at 0C in water: virtually insoluble;
231 g/l at 25C in dilute sulphuric/nitric acid dispro-portion into soluble copper(II) salts;
335 g/l at 50C insoluble in most organic solvents
in methanol: 156 g/l    
in ethanol: insoluble  

ORIGIN AND USE

Usage:
Copper is used as a conductor in the electrical industry; for heating and cooling pipes, as container material and as an alloying metal; in the form of Cu2O as antifouling paint (for ships' hulls); in the form of CuSO4 as a fungicide and algicide as well as to combat types of mildew; as whitewash to ward off vine pest and as a fertiliser in the form of CuSO45 H2O or Cu2O.

Origin/derivation:
Copper is found in elementary form and in ores such as chalcopyrite (CuFeS2), chalcocite (Cu2S) and cuprite (Cu2O). Copper is usually purified today using electrolytic refining methods. Fused-salt processes only account for roughly 10%. The copper in sulphide ores is generally separated by means of floatation.

Production figures:
In 1986: 513 million t (worldwide) [FISCHER, 1989]

Toxicity

Humans: 700-2100 mg/g dry liver tissue = lethal acc. SORBE, 1986
Mammals:
Rat LD50 159 mg/kg , oral, (Cu carbonate) acc. DVGW, 1988
Rat LD50 140 mg/kg , oral, (Cu chloride) acc. DVGW, 1988
Rat LD50 470 mg/kg , oral, (Cu oxide) acc. DVGW, 1988
Rat LD50 300 mg/kg , oral, (Cu sulphate) acc. DVGW, 1988
Aquatic organisms
Daphnia LD 0.8 mg/l (18 h), (Cu sulphate) acc. DVGW, 1988
Trout LD 0.8 mg/l (2-3 d), (Cu sulphate) acc. DVGW, 1988
Blue algae 0.03 mg/l Cu2+ = damage, (Cu sulphate) acc. DVGW, 1988
Green algae 1.1 mg/l Cu2+ = damage, (Cu sulphate) acc. DVGW, 1988

Cu is a powerful fish poison, the active concentration of which depends on the make-up of the water. The toxic effect is enhanced still further by cadmium, zinc and mercury.

Characteristic effects:

Humans/mammals: As a constituent part of numerous enzymes, Cu is an essential trace element. Poisoning mainly results from the inhalation of Cu dusts and Cu fumes. Poisoning caused by oral intake is rare since it causes nausea. The toxic effect is due to the bonding of free Cu ions with certain proteins and the resulting impairment of their physiological functions. Inhalation of fumes and dust displaces the blood in the nasal and mucous membranes and can cause perforation of the nasal septum. Infants are at a higher risk (possible mortality) where there is a high copper content in the drinking water. Death may be caused by cirrhosis of the liver.

Plants: Damage to roots which attacks the plasmalemma and destroys the normal membrane structure; inhibited root growth and formation of numerous short, brownish secondary roots. Cu becomes accumulated in the skin of the roots and in the cell walls. Chlorosis is produced by Cu displacing Fe from centres of metabolic physiology. In the same ecosystem aquatic plants absorb three times more Cu than plants on dry land.

ENVIRONMENTAL BEHAVIOUR

Water:
Cu is precipitated in saltwater thus explaining its low content compared to freshwater. Acid rain increases the solubility of copper ores. A high copper level in drinking water with low pH can usually be attributed to pipe corrosion. High copper levels can discolour the water and cause greenish deposits.

Air:
Cu is assigned to emission class 3 in the TA-Luft (ROTH, 1989). A greenish patina forms when Cu is exposed to damp air thus protecting the metal against further chemical action (corrosion).

Soil:
There is considerable retention of Cu by inorganic exchangers. Complex formation takes place with increasing pH. The solubility of Cu in soil is at its lowest at pH 5-6. Cu is subject to extreme accumulation in clay mineral layers. The Cu content in soil decreases with increasing depth of soil. Exchange reactions and the nitrogen content in the soil are important factors in the passive transport of immobile copper.

Degradation, decomposition products, half-life:
Cu(II) salts are the most stable Cu compounds.

Food chain:
Mammals and humans absorb 30% of copper in food via the stomach with 5% actually being resorbed and the rest being excreted again by way of the gallbladder. There is accumulation in the liver, brain and kidneys.

ENVIRONMENTAL STANDARDS

Medium/ acceptor Sector Country/organ. Status Value Cat. Remarks Source
Water: Drinkw CH

(L)

1.5 mg/l     acc. LAU-BW, 1989
Drinkw EC

G

0.1 mg/l   1) acc. DVGW, 1988
Drinkw EC

G

3 mg/l     acc. LAU-BW, 1989
Drinkw SU

(L)

0.1 mg/l     acc. LAU-BW, 1989
Drinkw USA

(L)

1 mg/l     acc. LAU-BW, 1989
Drinkw WHO

G

1 mg/l     acc. LAU-BW, 1989
Groundw D(HH)

G

0.05 mg/l   Investigation acc. LAU-BW, 1989
Groundw D(HH)

G

0.2 mg/l   Rehabilitation acc. LAU-BW, 1989
Groundw NL

G

15 m g/l   Reference acc. TERRA TECH, 6/94
Groundw NL

L

75 m g/l   Intervention acc. TERRA TECH, 6/94
Surface D

G

0.05 mg/l   2) B acc. DVGW, 1988
Surface D

G

0.30 mg/l   3) A acc. DVGW, 1988
Surface EC

G

0.02 mg/l   4) A1 acc. LAU-BW, 1989
Surface EC

G

0.05 mg/l   4) A1 acc. LAU-BW, 1989
Surface EC

G

0.05 mg/l   5) A2 acc. LAU-BW, 1989
Surface EC

G

1 mg/l   6) A3 acc. LAU-BW, 1989
Surface EC

G

0.04 mg/l   Salmonoid waters acc. LAU-BW, 1989
Waste water CH

G

0.01 mg/l   Quality goal acc. LAU-BW, 1989
Waste water CH

(L)

0.5 mg/l   Direct/indirect introduction acc. LAU-BW, 1989
Waste water D

G

2 mg/l     acc. LAU-BW, 1989
Irrigation D

G

0.2 mg/l   Field cultivation acc. LAU-BW, 1989
Irrigation D

G

0.05 mg/l   Cultivation under glass acc. LAU-BW, 1989
Irrigation GB

G

0.5 mg/l     acc. LAU-BW, 1989
Irrigation USA

(L)

0.2 mg/l     acc. LAU-BW, 1989
Irrigation USA

(L)

5 mg/l   7) acc. LAU-BW, 1989
Troughw D

G

0.01 mg/l     acc. LAU-BW, 1989
Troughw GB

G

0.2 mg/l     acc. LAU-BW, 1989
Troughw USA

(L)

1 mg/l   Cattle breeding acc. LAU-BW, 1989
Soil:   CH

G

50 mg/kg   Total content acc. LAU-BW, 1989
  CH

G

0.7 mg/kg   Soluble content acc. LAU-BW, 1989
  D(HH)

(G)

300 mg/kg   Investigation acc. LAU-BW, 1989
  NL

G

36 mg/kg AD   Reference acc. TERRA TECH, 6/94
  NL

L

190 mg/kg AD   Intervention acc. TERRA TECH, 6/94
Sewage sludge CH

L

1000 mg/kg DM     acc. LAU-BW, 1989
Sewage sludge D

L

100 mg/kg AD     acc. LAU-BW, 1989
Sewage sludge D

L

1200 mg/kg DM     acc. LAU-BW, 1989
Sewage sludge EC

L

50-140 mg/kg DM   Soil acc. LAU-BW, 1989
Sewage sludge EC

L

1000-1750 mg/kg DM     acc. LAU-BW, 1989
Fertiliser D

L

200 mg/kg   8) acc. LAU-BW, 1989
Compost A

G

100-1000 ppm DM     acc. LAU-BW, 1989
Compost CH

L

150 mg/kg DM     acc. LAU-BW, 1989
Compost D

G

100 mg/kg AD   Soil acc. LAU-BW, 1989
Compost D

G

2000 g/(haa)     acc. LAU-BW, 1989
Air: Emiss. D

L

20 mg/m3   Smoke, 9) acc. LAU-BW, 1989
Emiss. D

L

75 mg/m3   Smoke, 10) acc. LAU-BW, 1989
Workp AUS

L

1 mg/m3   Dust acc. MERIAN, 1984
Workp AUS

L

0.1 mg/m3   Smoke acc. MERIAN, 1984
Workp B

L

1 mg/m3   Dust acc. MERIAN, 1984
Workp B

L

0.2 mg/m3   Smoke acc. MERIAN, 1984
Workp D

L

0.1 mg/m3 MAK Smoke DFG, 1989
Workp D

L

1 mg/m3 MAK Dust DFG, 1989
Workp DDR

L

0.2 mg/m3   Smoke, mean value acc. MERIAN, 1984
Workp DDR

L

0.4 mg/m3   Smoke, short-time value acc. MERIAN, 1984
Workp CH

L

1 mg/m3   Dust acc. MERIAN, 1984
Workp CH

L

0.1 mg/m3   Smoke acc. MERIAN, 1984
Workp I

L

1 mg/m3   Dust acc. MERIAN, 1984
Workp I

L

0.2 mg/m3   Smoke acc. MERIAN, 1984
Workp NL

L

1 mg/m3   Dust acc. MERIAN, 1984
Workp NL

L

0.2 mg/m3   Smoke acc. MERIAN, 1984
Workp PL

L

1 mg/m3   Dust acc. MERIAN, 1984
Workp PL

L

0.1 mg/m3   Smoke acc. MERIAN, 1984
Workp RO

L

0.5 mg/m3   Dust, mean value acc. MERIAN, 1984
Workp RO

L

1.5 mg/m3   Dust, short-time value acc. MERIAN, 1984
Workp RO

L

0.05 mg/m3   Smoke, mean value acc. MERIAN, 1984
Workp RO

L

0.15 mg/m3   Smoke, short-time value acc. MERIAN, 1984
Workp S

L

1 mg/m3   Dust acc. MERIAN, 1984
Workp SF

L

1 mg/m3   Dust acc. MERIAN, 1984
Workp SF

L

0.1 mg/m3   Smoke acc. MERIAN, 1984
Workp SU

(L)

0.5 mg/m3     acc. LAU-BW, 1989
Workp USA

(L)

0.2 mg/m3 TWA Smoke acc. LAU-BW, 1989
Workp USA

(L)

1 mg/m3 TWA Dust acc. MERIAN, 1984
Workp YU

L

1 mg/m3   Dust acc. MERIAN, 1984
Workp YU

L

0.1 mg/m3   Smoke acc. MERIAN, 1984
Foodstuffs: Pectin CH

(L)

400 ppm     acc. DVGW, 1988
Tinned spinach CH

(L)

100 ppm     acc. DVGW, 1988
Margarine CH

(L)

100 ppm     acc. DVGW, 1988
Fruit juice CH

(L)

5-30 ppm     acc. DVGW, 1988
Milk CH

(L)

0.05 ppm     acc. DVGW, 1988
Beer CH

(L)

0.2 ppm     acc. DVGW, 1988

Notes:

1) On leaving pumping system
2) For drinking water treatment in each case: B = signifies impact limits up to which drinking water can be produced with the aid of currently tried and tested chemophysical methods
3) For drinking water treatment in each case: A = signifies impact limits up to which drinking water may be produced solely by natural methods
4) For drinking water treatment in each case: A1 = simple physical treatment and sterilisation
5) For drinking water treatment in each case: A2 = normal physical and chemical treatment/sterilisation
6) For drinking water treatment in each case: A3 = physical and refined chemical treatment, oxidation, adsorption and sterilisation
7) Only for short-term irrigation of certain soils
8) In organic, mineral mixed fertilisers
9) With mass flow 0.1 kg/h
10) With mass flow 3 kg/h

Comparison/reference values

Medium/origin Country Value Source
Water:
Lake Constance D 0.75-1.1 mg/l acc. DVGW, 1988
Rhine (Cologne): D 5-17 mg/l acc. DVGW, 1988
Rhine (Duisburg): D 2.9-24.6 mg/l acc. DVGW, 1988
Ruhr (Essen): D 14-26 mg/l acc. DVGW, 1988
Ruhr (Duisburg): D 6-11 mg/l acc. DVGW, 1988
Seawater   0.0005-0.03 mg/l acc. HOCK, 1988
Sediment:
Rhine D 250 mg/kg acc. DVGW, 1988
Ruhr D 900 mg/kg acc. DVGW, 1988
Fly ash, coal USA 45-616 mg/kg acc. HOCK, 1988
Sewage-sludge refuse compost D 50-5000 mg/kg acc. HOCK, 1988
Plants   2-12 mg/kg acc. HOCK, 1988

Assessment/comments

Copper is an important trace element for all living organisms. Humans require approx. 2 mg/day. Poisoning is rare since large quantities cause nausea. However, certain compounds are highly toxic to aquatic organisms.


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