Photocatalytic degradation of methamphetamine by UV/TiO2 – Kinetics, intermediates, and products

Photocatalytic mineralization of codeine by UV-A/TiO 2 —Kinetics, intermediates, and pathways

“…For the reaction conditions of C 0 = 0.1 mg/L, k and K were fitted to be 0.2mg/L/min and 1.24 L/mg, respectively, which are consistent with KC (0.124) << 1 justifying reasonably well the final pseudo-first order rate expression. TiO 2 doses.The increase of degradation rate according to photocatalyst concentration is consistent with increased active sites due to an increased catalyst amount that captures more photon to generate additional oxidant species for contaminant degradation, as previously found [28,32,33].As the photocatalyst dose increases beyond the attainment of maximum photon absorption, the reaction rate can decrease because of the clouding effect and light scattering exhibited by the excess photocatalyst particles resulting in an overall decrease in efficiency [25,26,33], in addition to hindrance of contaminant due to aggregation and sedimentation of photocatalyst particles thus reducing the contact between the contaminant and the active surface [25,33]. Fig.…”

“…These preliminary results showed that the irradiated TiO 2 was highly active for photocatalytic degradation of codeine. In our recent investigation of photocatalytic degradation of methamphetamine, similar, rapid removal of 90.4 µg/L of methamphetamine by an UV-irradiated TiO 2 suspension (0.1g/L)was observed within the first minute whereas no significant removals were observed either with the same suspension in dark or with UV irradiation alone [25].…”

Removal of Crotamiton from Reverse Osmosis Concentrate by a TiO2/Zeolite Composite Sheet

“…This result implied that crotamiton was degraded step by step and that the intermediate compounds accumulated at the same time. Kuo et al, investigated the photocatalytic mineralization of methamphetamine in a UVA/TiO 2 system and found that TOC disappeared more slowly than methamphetamine because the methamphetamine intermediates took some time to be mineralized [44]. A more detailed discussion on the degradation intermediates is given in Section 3.4.…”

“…of methamphetamine in a UVA/TiO2 system and found that TOC disappeared more slowly than methamphetamine because the methamphetamine intermediates took some time to be mineralized [44]. A more detailed discussion on the degradation intermediates is given in Section 3.4.…”

“…Jang et al, found that the target material (trichloroethylene) saturated the composite catalyst surface and reduced photon efficiency, leading to photocatalyst deactivation [45]. Kuo et al, showed that the degradation rates of codeine and methamphetamine increased with increasing initial concentration (100-250 µg/L) [44,46]. With the initial concentration at microgram per liter levels, the degradation rate may not be limited by the availability of catalytic sites but by contaminant concentration.…”