Photocatalytic Degradation of Ammonia Nitrogen with Suspended TiO2

Ammonia nitrogen is a common pollutant in water environment, and the nitrogen removal techniques have been studied extensively. In this work, a new kind of annular reactor was developed and the photocatalysis with suspended TiO₂ was used for degradation of ammonia nitrogen. The effects of experimental conditions on the ammonia degradation efficiency and the photocatalytic products in the effluent were investigated. The influence significance of the conditions were studied by the orthogonal experiments and the optimum conditions were found. The results showed that only when pH was higher than 7 the photocatalytic reaction could be done effectively and the degradation efficiency was gradually increasing with the pH rising. Comparing with no addition of oxidant, adding suitable amount oxidant would promote the degradation efficiency markedly, and made the nitrite nitrogen/nitrate nitrogen ratio below 100%. The influence significance of reaction conditions from high level to low level were pH, dosage of catalyst, reaction time and addition of H₂O₂. The degradation efficiency of ammonia nitrogen under the optimum conditions reached 90.12%.