| Title |
Application of High-performance Jet Loop Reactor for the Decolorization of Reactive black 5 and Mineralization of Oxalic Acid by Ozone |
| Authors |
변석종 ( Byeon Seogjong ) ; 조순행 ( Jo Sunhaeng ) ; 윤제용 ( Yun Jeyong ) ; 김수명 ( Kim Sumyeong ) |
| Keywords |
HJLR reactor; Mass transfer; Ozone; Oxalic acid; Reactive black 5 |
| Abstract |
As an ozone contactor, we newly adopted HJLR(High-performance Jet Loop Reactor) for the decolorization of Reactive black 5 and the mineralization of oxalic acid, which has been applied exclusively in biological wastewater treatments and well-known for high oxygen transfer characteristics. The ozonation efficiency for organic removals and ozone utilization depending on the mass transfer rate were compared to those of Stirred bubble column reactor, which was controlled by varing energy input in the HJLR and Stirred bubble column reactor. The results were as follows ; first, the decolorization rate of Reactive black 5 in the HJLR reactor was nearly proportional to the increasing k_(La) was increased by 25% from 13.0hr^(-1) to 16.4hr^(-1), 30% of the k¹(apparent reaction rate constant) was increased from 0.1966 to 0.2665min^(-1)(Stirred bubble column ; from 0.1790 to 0.2564min^(-1)). Ozone transfer was found to be a rate-determining step in decolorizing Reactive black 5, which was supported by that no residual ozone was detected in all of the experiments. Second, the mineralization of oxalic acid was not always proportional to the increasing k_(La), in the HJLR reactor is beneficial only when there are in ozone transfer limited regions. In addition, regardless of k_(La), the mineralization of oxalic acid was nearly accomplished within 60 minutes. It was interpreted as that the longer staying of residual ozone by whirling liquid in the HJLR reactor contributed to an high ozone utilization(83-94%), producing more OH radicals. |