PHOTOCATALYTIC DEGRADATION OF HIGH AMMONIA CONCENTRATION WATER SOLUTIONS BY TiO_2

摘要

Recent studies reported the use of suspended TiO_2 powder as photo catalyst in the degradation process of several organic and inorganic substances in water,like chlorinated hydrocarbons,alkyl-and alkanoloammines and ammonia.In order to evaluate the possibility of using this method for a further removal of ammonia from wastewater after a biological nitrification/denitrification treatment,a kinetic study of photo oxidation over TiO_2 of NHs/NHt in the high concentration range of 26-214 mg/1,has been carried out.Effects of pH,TiO_2,ammonium and dissolved O_2 concentration on the degradation efficiency and reaction products distribution(NO_2~-,NO_3~-e N_2)were studied.The results have shown that,at a catalyst concentration of 0,012%(p/v),the photo catalytic oxidation of ammonia can be described with the Langumuir-Hinshelwood kinetic model,as reported by several authors.