Balakrishnan Akash, Gopalram Keerthiga, Appunni Sowmya
Department of Chemical Engineering, School of Bioengineering, Faculty of Engineering and Technology, SRM Institute of Science and Technology, SRM Nagar, Kattankulathur, 603 203, Kanchipuram, Chennai, Tamil Nadu, India.
Environ Sci Pollut Res Int. 2021 Feb 27. doi: 10.1007/s11356-021-12928-4.
Effective pesticide remediation technology demands amendments in the advanced oxidation process for its continuous treatment and catalyst recovery. The evidence of 2,4-dichlorophenoxyacetic acid (2,4-D), an herbicide in water bodies, poses a major environmental threat to both humans and aquatic organisms. In the present study, a recirculation type photocatalytic reactor was developed to treat 2,4-dichlorophenoxyacetic acid using chitosan-TiO beads prepared via impregnation method under UV light. At optimized conditions, chitosan-TiO beads showed a maximum photocatalytic degradation of 86% than commercial TiO (65%) and followed pseudo first-order reaction. The 2,4-D degradation follows pseudo first-order kinetics under UV irradiation with a rate constant of 0.12 h, and the intermediates were identified using LCMS analysis. The total operational cost of the chitosan-TiO catalyst was found to be profitable (Rs. 1323 for 2 L) than that of TiO (Rs. 1679) at optimized conditions. The beads were reusable up to 4 consecutive cycles without loss in efficiency. This study briefs photocatalytic removal of 2,4-dichlorophenoxyacetic acid in a recirculation-type reactor for its reliability, low cost, efficiency, reusability, and commercialization.
有效的农药修复技术要求改进高级氧化工艺以实现连续处理和催化剂回收。水体中的除草剂2,4-二氯苯氧乙酸（2,4-D）对人类和水生生物都构成重大环境威胁。在本研究中，开发了一种循环式光催化反应器，以在紫外光下使用通过浸渍法制备的壳聚糖-TiO珠处理2,4-二氯苯氧乙酸。在优化条件下，壳聚糖-TiO珠的光催化降解率最高可达86%，高于商业TiO（65%），且遵循准一级反应。2,4-D的降解在紫外照射下遵循准一级动力学，速率常数为0.12 h，并用LCMS分析鉴定了中间体。在优化条件下，发现壳聚糖-TiO催化剂的总运行成本（2升为1323卢比）比TiO（1679卢比）更具成本效益。这些珠子可重复使用多达4个连续循环而不损失效率。本研究简述了在循环式反应器中光催化去除2,4-二氯苯氧乙酸的可靠性、低成本、高效性、可重复使用性和商业化前景。
