Copper ion removal

Robinson and Walsh have reviewed earlier cell designs. The performance of a 500 A pilot plant reactor for copper ion removal is described. Simplified expressions were derived for mass transport both in single pass [243] and batch recirculation [244]. For a detailed discussion of the principle and the role of the rotating cylinder electrode reactor in metal ion removal the reader is referred to Refs. [13] and [241] (46 references). 

Adding copper(l) chloride to the molten glass makes the process reversible. When light intensity diminishes, copper ions remove electrons from silver atoms, converting the silver atoms into silver ions. The silver ions then migrate back to the silver chloride crystals. The glass becomes transparent again. 

Wiencek JM and Qutubuddin S. Microemulsion Uquid membranes II. Copper ion removal from buffered and unbuffered aqueous feed. Sep Sci Technol 1992 27 1407-1422. 

CS-based mixed matrix membranes and nanocomposite membranes are much useful in heavy metal removal. Salehi et al. [82] synthesized amine functionalized multiwalled carbon nanotubes (F-MWCNTs) and utilized to prepare novel CS/polyvinyl alcohol (PVA) thin adsorptive membranes for copper ion removal from water. Copper ion adsorption on the membranes was more favorable at higher CNT contents as well as increased temperatures. The adsorption capacity of the membrane containing 2 wt.% CNTs (20.1 mg/g at 40°C) was almost twice as large as that of the plain membrane (11.1 mg/g). Salehi et al. [83] used PE glycol and amino-modified MWCNTs to modify CS/PVA thin adsorptive membranes for copper ion adsorption. Adsorption capacity of CS/PVA membrane was increased from 11 to 30 mg/g by the addition of 5 wt.% PEG to the blend. Addition of CNTs,... 

Fortunately, in the presence of excess copper(II)nitrate, the elimination reaction is an order of magnitude slower than the desired Diels-Alder reaction with cyclopentadiene, so that upon addition of an excess of cyclopentadiene and copper(II)nitrate, 4.51 is converted smoothly into copper complex 4.53. Removal of the copper ions by treatment with an aqueous EDTA solution afforded in 71% yield crude Diels-Alder adduct 4.54. Catalysis of the Diels-Alder reaction by nickel(II)nitrate is also... 

Reagents. Copper ion solution, 0.04M. Wash analytical grade copper with petroleum spirit (b.p. 40-60 °C) to remove any surface grease and dry at 100 °C. Weigh accurately about 1.25 g of the pure copper, dissolve it in 5mL of concentrated nitric acid, and dilute to 1 L in a graduated flask. Titrate this... 

This method is used to remove ionic species such as heavy metals, phosphates, or nitrates. It is the reversible exchange of ionic species between a resin and the liquid. For example, a cation resin will exchange positive ions such as hydrogen ions for copper ions that are in solution. Similarly, certain anion resins might replace phosphate ions with hydroxyl ions. 

Iwamoto, M., Mizuno, N. and Yahiro, H. (1991) Removal of nitrogen monoxide over copper ion-exchanged zeolite catalysts, Sekiyu Gakkaishi, 34, 375. 

As stated previously, the total normal cytoplasmic free copper concentration is less than 10 18 M or less than one copper ion per cell. In thermodynamic terms, almost all hydrated copper ions are immediately and tightly coordinated by amino acids or biopolymers—peptides, proteins, and other species with free sulfur ligands. An excess of copper ions activates metallothionein synthesis for storage or removal of the excess. Copper chaperones mediate transfer of copper ions from extracellular or storage locations to their target proteins. Instability of copper ion concentrations in vivo results in various disease states. Three of these—FALS, Menkes, and Wilson s diseases—are described below. 

The use of GSNO in vasodilator research is particularly unsafe as the effect of copper ions, as determined by in vitro studies, is much more complex than with SNAP. Briefly, Cu(I) ions complex not only with GSNO but also with glutathione disulfide (a reaction product) and this means that the concentration of Cu(l) ions falls as the reaction proceeds, killing the reaction when all the Cu(I) ions have been complexed [22]. The absence of any observed effect when GSNO is used as a vasodilator may be due to removal of copper ions by complexation with glutathione disulfide. 

After a period of time, a steep concentration gradient forms around the electrode since the solution immediately adjacent to the HMDE is entirely depleted of Cu. In response, (solvated) Cu analyte ions from the bulk of the solution will diffuse toward the HMDE and themselves be reduced. After a further period of time, all of the copper ions will have been removed from solution and accumulate on the surface of the drop (Figure 5.6(b)). Here, we say that we have exhausted the solution. ... 

Iwamoto, M Yahiro, H Tanda, K Mizuno, N Mine, Y Kagawa, S. Removal of nitrogen monoxide through a novel catalytic process. 1. Decomposition on excessively copper-ion-exchanged ZSM-5 zeolites. J., Phys. Chem., 1991, Volume 95, 3727-3730. 

A fourth application is a convenient assessment of the removal of a transition metal by a supported chelator vs sorption on the substrate. It appears that the supported chelators were able to remove copper ion in a quantitative manner, but a goodly proportion (83%) was removed by sorption on silica gel. In contrast, a Linde molecular sieve (alone) with fairly defined pores removed about half of the copper ion through sorption. 

Reaction of Ethylenediamine in Absence of Copper Ion. Using 0.015 mole of ethylenediamine and omitting copper ion, only 4-iminopentane-2-one was obtained after removal of solvent under reduced pressure [0.4 gram (40%) white crystals, b.p. 80 -82° 2 mm.]. 

In marked contrast, l,5-bis(2-carboxyphenyl)-3-cyanoformazan reacted with copper(II) acetate in methanol to give a complex containing water which could not be removed by conventional physical methods. Further, the product was not converted into an anionic complex on treatment with potassium acetate. The clear implication of this is that one carboxyl group is not coordinated to the copper ion and structure (183) is preferred to (184) proposed earlier.129 It is, of course, possible that the complex has a dinuclear, oxygen-bridged structure of the type proposed for the... 

---