Glyphosate degradation in water employing the H2O2/UVC process

WATER RESEARCH

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2010 vol. 44 p. 3875 - 3882

0043-1354

Glyphosate is the organophosphate herbicide most widely used in the world. Any form ofspill or discharge, even if unintentional, can be transferred to the water due to its highsolubility. The combination of hydrogen peroxide and UV radiation could be a suitableoption to decrease glyphosate concentration to acceptable limits. In this work, the effectsof initial pH, hydrogen peroxide initial concentration, and incident radiation in glyphosatedegradation were studied. The experimental device was a cylinder irradiated with twotubular, germicidal lamps. Conversion of glyphosate increases significantly from pH = 3-7.From this value on, the increase becomes much less noticeable. The reaction rate dependson the initial herbicide concentration and has an optimum plateau of a hydrogen peroxideto glyphosate molar concentration ratio between 7 and 19. The expected non lineardependence on the irradiation rate was observed. The identification of critical reactionintermediaries, and the quantification of the main end products were possible and it led topropose a plausible degradation path. The achieved quantification of the mineralizationextent is a positive indicator for the possible application of a rather simple technology foran in situ solution for some of the problems derived from the intensive use of glyphosate.