Photodegradation of herbicide dicamba with TiO2 immobilized on HZSM-11 zeolite

JUAN MONTAÑÉZ; SILVINA GOMEZ; LILIANA PIERELLA; ANA SANTIAGO

INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH

UNIV TEHRAN

Lugar: Tehran; Año: 2015 vol. 9 p. 1237 - 1244

1735-6865

TiO2 is broadly used as a photocatalyst to remove a wide range of organic pollutants in water media, including herbicides such as dicamba (3,6-dichloro-2-methoxybenzoic acid). However, removal of TiO2 requires expensive methods of separation. Also, this compound can not be reused in several cycles because it tends to agglomerate, losing catalytic surface. In our work, photodegradation of dicamba using TiO2 supported on HZSM-11 zeolite was investigated. Four photocatalysts with different weight percentages (wt%) of TiO2 were evaluated: 3%, 10%, 30% and 50%. The effects of the catalyst concentration, the initial pH value and the repeatability of the photocatalytic activity after multiple cycles of reuse were also evaluated. Results showed complete degradation of dicamba within 120 min with the TiO2/HZSM-11 (30 wt%) catalyst. Also, this catalyst is stable (no detectable leaching was observed), can be easily removed from treated solutions and it is reusable for at least nine consecutive cycles. These are important advantages over unsupported TiO2, making it a good photocatalyst for the treatment of water courses polluted with dicamba.