the main aim of this research is to determine optimal leaching conditions; eh, ph and complexing agent concentrations, for recovery of copper from hydroxide sludges such as those produced by electroplating shops, metal finishers, treatment of acid mine drainage, and industrial wastewater in general. this has been preceded by a theoretical approach and numerical and computer calculation. potenti...

Selective membranes containing a few micrograms of various complexing reagents in a polyvinyl chloride (PVC) matrix were produced in order to determine low uranium concentrations in water. The membranes were produced on the surfaces of quartz glasses, and immersed in water solutions containing uranium salts (5 - 50 ng/mL). By the end of the equilibration time, the membranes were left to dry and...

A calculational method is developed for spectrophotometric determination of stoichiometrics and individual equilibrium constants in the complexing of metal ions with metallochromic indicators. Implicit expressions are developed for the calculation of all parameters necessary to describe mixtures of 1 : 1, 1 : 2 and 2 : 1 metal-indicator complexes. The analysis of titration curves entails a seri...

Assessment of complexing properties and mechanisms involved in covalently-bonded carbon-supported hyperbranched polyethyleneimines towards metal ions environmental technical interest.

Strong, dissolved, copper-complexing ligands are known to control copper speciation and bioavailability in most marine waters. We are testing the hypothesis that metal-responsive production of such ligands occurs in the Elizabeth River estuary, and that picoplankton and bacterioplankton produce the ligands. Recent studies utilizing cultures of marine picoplankton (Synechococcus) and bacteriopla...

In the preparation of nanostructured materials, it is important to optimize synthesis parameters in order to obtain the desired material. This work investigates the role of complexing agents, oxalic acid and tartaric acid, in the production of MgO nanocrystals. Results from simultaneous thermogravimetric analysis (STA) show that the two different synthesis routes yield precursors with different...

In order to control the deposition of Zn-related films by chemical bath deposition, effects Zn-complexing agent are analyzed. ZnS were produced technique employing sodium citrate, ethanolamine and Triethanolamine as complexing agents. The conditions for (ZnO) thin obtained through a thermodynamic analysis, using distribution diagrams molar fraction Zn complexes. From species Zn-ethanolamine, Zn...