SOL1: A program for the simulation of complex equilibria using a personal computer

Abstract

SUMMARYThe program SOLI, written in Turbo-PASCAL for use on a personal computers (IBM-PC or compatible), has been developed for calculating the equilibrium concentrations of the species in multicomponent ligand-metal mixtures of up to 21 components and 150 species. The main features are the easy data input system, the possibility of three different tasks (calculating the composition of a single soiution, simulating titration curves and calculating the species distributíon as a function of pH) and procedures for drawing the calculated curves on Roland DXY plotters. The program has been tested by a study of six different complex systems.

Determination of the equilibrium formation constants of two U(vi)–peroxide complexes at alkaline pH

“…This approach has been applied successfully to the simulation of complex equilibria in multi-metal-multi-ligand systems. 30 With the chemical species postulated for the model of the chemical equilibrium (shown in Table I), the values of the formation constants obtained with the STAR program are log * b 1,1,4 = -28.10 ± 0.14 and log * b 1,2,6 = -46.9 ± 0.2 (the STAR program calculates formation constants referred to the formation or consumption of H + , instead of OH -, even at alkaline pH). By using the water dissociation constant, the values obtained are: log b 1,1,4 = 27.9 ± 0.1 and log b 1,2,6 = 37.1 ± 0.2.…”

Sorption of Cd(II) and Pb(II) from aqueous solutions by a low-rank coal (leonardite)

“…In aqueous solutions, Cd(II) and Pb(II) may exist in different chemical species. In this way, according to the distribution of ionic species obtained from the computer program SOL 1 [25], in this pH range and at the metal concentration range used, the Cd(II) in the adsorptive solution is likely to be found as free ions (Cd 2+ > 99.9%) in equilibrium with the solvated species [Cd(OH)] + . On the other hand lead mainly exists in the form Pb 2+ (>98%) whereas the hydrolyzed and polymeric forms ([Pb(OH)] + , [Pb 2 (OH) 2 ] + ) are present in a percentage <2%.…”

Ni(ll) biosorption by Rhizopus arrhizus Env 3: the study of important parameters in biomass biosorption

“…Nickel biosorption increased as the pH increased, with the highest uptake capacity being obtained at pH 8. According to the distribution of ionic species of nickel by the computer program SOL 1,18, 19 in the pH range 1–7, one major hydrolysed nickel ion (90%) exists in solution. The increase in Ni 2+ accumulation as the pH increased was a consequence of the increase in negative charge at the surface of cells and more efficient competition of Ni 2+ with H + for binding sites 18…”