Photooxidation/adsorption of arsenic (III) in aqueous solution over bentonite/chitosan/TiO2 heterostructured catalyst

Arsenic contamination of the environment is a serious health hazard due to its toxicity and carcinogenic effects thus demanding developed and robust removal methodologies. In this study, bentonite/chitosan/titania (BT/CS-TiO2) was developed to boost photo-oxidation/adsorption efficiency while providing a low-cost and potential heterostructured platform for arsenic removal from aqueous media. Under UV irradiation, BT/CS-TiO(2 )hetemstructured exhibited the desired capability (97%) of boosting oxidize toxic As-III to minor toxic As-V. Results confirmed that center dot OH radicals available at TiO2 sites under UV light played a critical role in the proposed photooxidation process of As-III. BT/CS exhibited a high adsorption capacity (160 mg g(-1)) for As(V )removal due to its electrostatic interaction and surface complexation. Additionally, BT/CS-TiO2 heterostructured showed satisfactory recyclability with no considerable interferences in the presence of coexisting anions due to the suitability of the valence band position of TiO2 for the oxidation of As-III as well as the presence of CS into BT layers. Thereby, the findings revealed that impregnation of TiO2 in BT/CS is a promising approach for arsenic removal.

Automated summary

A bentonite/chitosan/titania composite material was developed for arsenic removal, showing high efficiency and good recyclability. The addition of TiO2 in the composite material was found to improve the arsenic removal efficiency, as demonstrated in the study.