Removal of Cu

Valentine el al. demonstrated that Cu2+ ions are in the same site in native Cu, Zn-SOD protein and CuESOD (E = empty, i.e. with removal of Zn ion from the native Cu, Zn-SOD) and the activity of the CuESOD is at least 80 5% that of the native Cu, Zn-SOD [99], However, the EZnSOD (E = empty, i.e. with removal of Cu ion from the native Cu, Zn-SOD) does not show any activity for catalytic dismutation of 02. This suggests Cu2+ present in the Cu, Zn-SOD is essential for 02" dismutation even though Zn2+ is also required for dismutase activity [100-102],... 

Leaves of Sumac were used for removal of ions in aqueous solution. Tannins were extracted from the leaves of sumac by extracting with 70% (v/v) acetone-water solution. For the total tarmin determination Folin-Ciocalteu method was used and tannin content was found 27%. Various adsorption parameters for the effective removal of Cu + ions by using sumac leaves as an adsorbent from aqueous solutions were studied and optimized. 

Industrial uses for H-S include 111 die preparation of sullides. such as sodium sullide and sodium hydrosullide 12) the production of sulfur-bearing organic compounds, such as lliioplienes. mercaptans. and organic sullides (3) the removal of Cu. Cd. and Ti from spent catalysis where the gas acts as a precipitant (4) Ihe lormulation of extreme-pressure lubricants and (51 die preparation of rare-eardl phosphors used ill color TV lubes. See also Coal. 

It appears that Narragansett Bay retains less than 5 % of the nutrients, less than 10 % of the Mn, and perhaps 15-30 % of the Cd that is input to the system each year. The removal of Cu (70-95 %) and Pb (80-100 %) is much more effective. Somewhere between 25-65 % of the petroleum hydrocarbons entering the Bay remain in the sediments. These estimates are in agreement with the behavior of the different materials in sediment-water flux measurements and in experiments using the large MERL mesocosms. 

Horsfall Jnr M., Abia, A.A., and Spiff, A.I. 2003. Removal of Cu (II) and Zn (II) ions from waste water by cassava (Manihot esculenta Cranz) waste biomass. African Journal of Biotechnology, 2 360. ... 

Association ofpulp and activated carbon for the removal of Cu and phenol... 

Figure 6.27 Demonstration of a local deposition and selective removal of Cu clusters on Au(lll) in the system Au(lll)/0.05 M H2SO4 + 0.1 mM CUSO4 at T = 298 K [6.188]. (a) local deposition of copper clusters and (b) selective removal of a cluster by applying a very positive tip potential Ef = 500 mV vs. Cu/Cu. ...

Experiments were performed on the removal of Cu" from aqueous solution at pH 1.5 and 25 C with the Dowex XFS 4195.02. These data allowed the development of a mathematical equation describing the isotherm equilibrium adsorption of Cu, using the Freundlich equation. These results are shown in Figure 1. 

The effects of varying initial Cu concentration on the removal of Cu" were examined by exposing 0.2 g of resin with 80 g quantities of solutions containing 40 - 120 ppm Cu. The experimental data were... 

The effects of the initial Cu concentration upon the removal fraction are shown in Figure 4. In Figure 4, the symbols are the data, and the solid lines are the best-fit prediction from the removal model. Removal fractions increase with decreasing initial Cu concentration. These observations indicate that a controlling step for the removal of Cu from aqueous solution is diffusion of Cu through the resin. 

The effects of varying the relative amounts of solution and resin on the removal of Cu were examined by treating varying quantities of 80 ppm Cu solution with 0.2 g fixed quantities of the Dowex XFS 4195.02 resin at 25 C. The removal-fraction versus removal-duration data were applied to the removal model in order to identify effects of varying the proportions of solution and resin on the removal of Cu. As is shown in Figure 5, the intraparticle diffusivities of Cu" through the resin increase with the amounts of solution. This may indicate that increased mass ratios of solution to resin result in increased Cu removal. 

In order to evaluate the effects of other transition metal ions on the removal of Cu, solutions containing both Cu and Ni were treated with the Dowex XFS 4195.02 resin. Data from these experiments are shown graphically in Figure 6. The removal of Cu" from aqueous solutions is slightly retarded by the presence of Ni". ... 

The following conclusions were drawn on the basis of experimental data for the removal of heavy metals from aqueous solutions in the presence of Dowex 4195.02 ion exchange resin, and the regeneration of spent Dowex XFS 4195.02 in the oresence of aqueous ammonia as a regenerant. ) The removal of Cu from aqueous solutions is controlled by intraparticle diffusion of Cu through the resin. Removal rates of... 

After oral administration, the blood levels of Cu rise more rapidly and subsequently decrease more slowly in the patients than in the controls. The peak blood level is usually higher in the patient. This was also used as an argument in favor of increased copper absorption, but again the results can be equally well explained by decreased rate of removal of Cu from the blood. Following intravenous administration, the disappearance from the blood is slower in patients than in controls, which bears out the point above. The secondary rise of activity in the blood, due to the release of ceruloplasmin-bound Cu probably from the liver, is regularly seen in the controls, but never in the patients. The patient with Wilson s disease seems to be unable to incorporate copper into ceruloplasmin, and, interestingly, this is the case even in those rare patients with normal blood levels of ceruloplasmin (89). 

Copper is essential for catalysis removal of Cu(II) or its replacement with other metals results in the complete loss of cataljdic activity (2) with the exception of Ag(I), for which catalytic activity up to... 

The consensus view of CuNiR function, and that considered here, is that the reduction of nitrite occurs at the type 2 Cu center. However, enzyme deficient in type 2 Cu has consistently been reported to have an NiR activity, up to 60% of the wild-type under some conditions, and nitrite has been shown to bind to T2DAxNiR. The difficulty of retaining a type 2 site geometry and environment (proposed to be required for activity), other than the loss or removal of Cu from the native enzyme, has made it difficult to exclude the possibility that the observed activity is due to residual Cu in the type 2 center. The proposal that T2DN1R has activity is controversial. 

For some combinations of heavy metals, it is also necessary to use enhancement solutions to ensure the simultaneous removal of all pollutants (Ottosen et ai, 2003). Especially, the presence of As in the soil necessitate alternative solutions to the acidic front since As generally has low mobility under acidic conditions, whereas As is more mobile under alkaline conditions, where most heavy metals are not mobile (Le Hecho, TelUer, and Astruc, 1998 Ottosen et aL, 2000). Le Hecho, Tellier, and Astruc (1998) conducted laboratory experiments with spiked soils, where the pollutants were As and Cr. Successful remediation was obtained in the developing alkaline front combined with the injection of sodium hypochlorite. As was mobile in the alkaline environment, and Cr(III) was oxidized to Cr(VI) by hypochlorite and mobilized in the alkaline environment. In loamy sand polluted with Cu and As from wood preservation. As and Cu were mobile simultaneously after the addition of NH3 to the soil (Ottosen et a/., 2000). As was mobile due to the alkaline environment and Cu formed charged tetra-ammine complexes. For the simultaneous mobilization and electrochemical removal of Cu, Cr, and As, ammonium citrate has shown to be successful (Ottosen et al, 2003). 

Nystroem GM, Ottosen LM, ViUumsen A. (2005b). Electrodialytic removal of Cu, Zn, Pb, and Cd from harbor sediment Influence of changing experimental conditions. Environmental Science Technology 39(8) 2906-2911. 

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