B. Nowack, A. Stone
Oct 21, 2000
Citations
4
Influential Citations
78
Citations
Quality indicators
Journal
Environmental Science & Technology
Abstract
Phosphonates are used in an increasing variety of industrial and household applications including cooling waters systems, oil production, textile industry, and detergents. Phosphonates are not biodegraded during wastewater treatment but instead are removed by adsorption onto sludge. This study investigates the degradation of phosphonates in the presence of MnII and molecular oxygen. The half-life for the reaction of nitrilotris(methylene)phosphonic acid (NTMP) in the presence of equimolar MnII and in equilibrium with 0.21 atm O2 is 10 min at pH 6.5, with the reaction occurring more slowly under more alkaline or acidic pH values. The presence of other cations such as CaII, ZnII, and CuII can considerably slow the reaction by competing with MnII for NTMP. Catalytic MnII is regenerated in cyclic fashion as the reaction takes place. Although generation of a MnIII-containing intermediate appears likely, electron transfer within the ternary complex O2−MnII−NTMP cannot be completely ruled out. Formate ion, ortho...