Photodegradation of glyphosate active ingredient and commercial formulations by application of the UV/H2O2 process

C.S. ZALAZAR; A. MANASSERO; M.L. MARIANI; A.C. NEGRO; A.E. CASSANO

San Pablo, Brasil

Congreso; V EPOA: Encontro sobre Aplicaçoes Ambientais de Processos Oxidativos Avançados; 2009

Universidad de San Pablo

Glyphosate (N-phosphonomethyl glycine) is a non-selective, post-emergence, broad-spectrum organophosphate herbicide, which is the one most used in the world. Argentina is the second largest world producer of glyphosate-resistant (GR) soy. This production has been accompanied by an increase in the herbicide use (over 160 million L between 2004 and 2005). The improper disposal of herbicide containers wastes has led to contamination of soil, ground and surface waters. Due to the lack of availability of small scale, on-site treatment technologies, only a small amount of this waste is currently annihilated. The combination of H2O2 and UV radiation could be a convenient process for treating this type of pollutants. In this work the effects of H2O2 initial concentration, initial pH and irradiation rates in the glyphosate active ingredient degradation were studied. In addition to this, the main reaction intermediates were identified with the intention of proposing a plausible reaction pathway.