Thermodynamic parameters for protonation of 1,4-bis(3-aminopropyl)-piperazine (BAPP) and its metal complexation with some divalent metal ions were determined in aqueous solution at constant ionic strength (0.1 M NaNO(3)) using a potentiometric technique. The order of -ΔG(0) and -ΔH(0) was found to obey Co(2+) < Ni(2+) < Cu(2+) > Zn(2+), in accordance with the Irving-Williams order. The formatio...

Advances in Agronomy, Volume 90 Copyright 2006, Elsevier Inc. All rights reserved. 0065-2113/06 $35.00 DOI: 10.1016/S0065-2113(06)90005-4 II. M echanistic Studies of Cell Wall Adsorption A . P artitioning Relationships Versus Surface Complexation Modeling B . C onstraints on Bacterial Cell Wall‐Protonation Reactions C . C onstraints on Mechanisms of Metal Adsorption onto Bacteria I II. C hallen...

the complexation of sodium molybdate with para-sulfonatocalix [4] arene was studied in thetemperature range from 20 to 40 °c and ph = 5.8 by spectroscopic method in water solution. thestability constants of complexes were calculated by the multiwavelength analysis of spectral datausing squad program. the equilibrium constant, spectroscopic data, molar absorptivities andconcentrations of all spe...

The complexation of sodium molybdate with para-sulfonatocalix [4] arene was studied in thetemperature range from 20 to 40 °C and pH = 5.8 by spectroscopic method in water solution. Thestability constants of complexes were calculated by the multiwavelength analysis of spectral datausing SQUAD program. The equilibrium constant, spectroscopic data, molar absorptivities andconcentrations of all spe...

The protonation constants of glycine, L-alanine, glycyl-glycine, glycyl-glycyl-glycine and glycyl-L-alanine have been determined in 10-80% (v/v) ethanol-water mixtures at 25 °C and constant ionic strength (0.1 mol L-1 sodium perchlorate), by potentiometric technique and calculated using a suitable computer program, which employs a nonlinear least-squares method. The effect of solvent compositio...

Kinetics of phosphate removal by Fe(III) was investigated by both preformed and in situ formed hydrous ferric oxides (HFO) at pH 6.0-8.0. A pseudo-second-order empirical model was found to adequately describe phosphate removal in the two cases. The Elovich and intra-particle diffusion models, however, were only capable of describing phosphate adsorption to preformed HFO (PF-HFO). By using surfa...

The Constant Capacitance model provided a quantitative description of o-phosphate adsorption by 44 noncalcareous soils whose pH values ranged from 4.9 to 7.6. The intrinsic surface protonationdissociation constants, capacitance density, and phosphate packing area parameters required by the model were adopted from model calculations on reference hydrous oxide minerals. The intrinsic phosphate su...