Chelating ability and solubility of DTPA, EDTA and beta-ADA in alkaline hydrogen peroxide environment

The abilities of diethylenetriaminepentaaceticacid (DTPA), ethylenediaminet etraaceticacid (EDTA), beta-alaninediacetic acid (ADA), separately and in c ombination, to bind and transport transition metals (Fe, Mn) were studied i n four pilot-plant recirculation systems simulating alkaline (pH 10-11) hyd rogen peroxide bleaching environments. Gas chromatography, atomic absorptio n spectroscopy and distribution computing were applied in the analyses and calculations. DTPA was able to bind 60% of manganese, EDTA 100% and beta-AD A 40%. EDTA could bind only 10-20% of iron. The ligands appeared more solub le in the presence of iron and manganese probably due to the significant so lubility of the manganese complexes.