Study of visible-light photocatalytic degradation of 2,4-dichlorophenoxy acetic acid in batch and circulated-mode photoreactors
- 9 Downloads
The consumption of pesticides and chemical fertilizers is one of the major environmental and health problems. In this report, 2,4-dichlorophenoxyacetic acid (2,4-D) was chosen to evaluate the impact of photodegradation using LED (Light-emitting diode) (400 and 365 nm) sources in batch and programmable circulated-mode photoreactors respectively.
A β-cyclodextrin (β-CD) grafted titanium dioxide P25 (P25/β-CD) and complexation of 2,4-D and β-CD were synthesized via photoinduced and spray-drying methods, respectively. The structures were characterized. Moreover, we investigated the effects of the amount of catalyst, the β-CD amount on bed catalyst, irradiation time, kind of photoreactor on the photocatalytic degradation efficiency.
Based on the results of experiments in batch reactor, the optimum amount of TiO2, β-CD grafted by catalyst were 1 and 0.1 g/L, respectively. In batch-mode the photodegradation efficiency of 2,4-D after 5 h with P25, P25/β-CD as a photocatalyst and 2,4-D/β-CD complex with P25 photocatalyst were approximately 81, 85 and 95% respectively. After 8 h of irradiation in circulated-mode reactor, degradation yields with P25, P25/β-CD and 2,4-D/β-CD complex along with P25 were 89, 91 and 96% respectively. On the other hand, the circulated-mode photoreactor with high efficiency was appropriate to degradation of the high concentration of 2,4-D solution (200 mg/L). After 5 successive cycles with 25 h of irradiation, P25 and P25/β-CD maintained as high 2,4-D removal efficiency as 82.6, 84% respectively, with excellent stability and reusability.
The photodegradation method can be used as an effective and environmental friendly process in the degradation of organic compound.
Keywords2,4-Dichlorophenoxyacetic acid (2,4-D) Light-emitting diode (LED) 2,4-D/β-CD complex Batch-mode photoreactor Circulated-mode photoreactor
The authors acknowledge the support by Shahid Sadoughi University of Medical Sciences and Institute for Advanced Studies in Basic Sciences (IASBS) Research Council of this work.
The present work was financially supported by Shahid Sadoughi University of Medical Sciences.
Compliance with ethical standards
Conflicts of interest
The authors confirm no conflicts of interest associated with this publication.
Consent for publication
All authors agreed to publish this article.
Ethics approval and consent to participate
There was no human participation in this study.
- 26.Pitchaimuthu S, Lakshmi G, Velusamy P. Enhanced photocatalytic activity of TiO2 using β-Cyclodextrin on solar light assisted decoloration of azocarmine G dye. J adv Chem Sci. 2014:9–14.Google Scholar