PHOTOCATALYTIC DEGRADATION OF N-METHYL-2-PYRROLIDONE IN AQUEOUS SOLUTIONS USING LIGHT SOURCES OF UVA, UVC AND UVLED

摘要

In the present study, photocatalytic decomposition of N-methyl-2-pyrrolidone (NMP) using light sources of UVA, UVC and UVLED was investigated. The effects of different parameters such as NMP initial concentration, pH value, catalyst loading, inorganic salts and the type of light sources on the reaction rate were evaluated, and optimum conditions were determined. The results of experiments showed that catalyst loading of 0.9 g/1 TiO_2 was the optimum and further increase in the TiO_2 loading reduced removal efficiency. The highest photodegradation reaction rate was obtained in neutral condition rather than acidic or alkaline condition. Furthermore, the effects of inorganic salts were investigated. Result showed that photocatalytic degradation rate was affected significantly in the presence of bicarbonate and chloride. The experimental data showed that the photocatalytic degradation of NMP can be simulated by using pseudo-first-order reaction rate expression. The apparent rate constant (k_(obs) over TiO_2 photocatalyst with 254 nm ultraviolet lamp (UVC), 365 nm ultraviolet lamp (UVA), and UVLED were 0.0454, 0.0205 and 0.0125 min~(-1) respectively.