Phosphate Modification of Nano Titania and Its Effect on the Photodegradation of EDTA

Effat Iravani,Sareh Ammari Allahyari,Meisam Torab-Mostaedi

doi:10.5935/0103-5053.20160057

Abstract

The surface of nano titania was phosphate modified and characterized by X-ray diffraction (XRD), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), energy dispersive X-ray analysis (EDX), and elemental analysis (CHN) to show the existence of phosphate in the modified nano titania. The resultant phosphated nano titania was applied for photocatalytic degradation of ethylenediaminetetraacetic acid disodium salt (EDTA) in aqueous solution. The crystallite size and crystalline phase showed no considerable change after modification, hence photocatalytic effect improvement of phosphate modified nano titania compared with the pure nano titania could be probably due to the existence of phosphate groups on the surface. The changes of the initial pH, photocatalyst dosage and EDTA concentration were tested in the degradation experiments. The pseudo-first-order kinetic model described the dynamic behavior for the photocatalytic degradation of EDTA using phosphate modified nano titania.

Highlights

Ethylenediaminetetraacetic acid (EDTA) is mainly used as acid and sodium salt extensively, in several industrial and domestic applications like photo and paper industry
This paper describes the photocatalytic degradation of EDTA in the aqueous solution using phosphate modified nano titania with the final aim of establishing the best degradation conditions
After calcination at 400 °C for 2 hours, the organic rest was removed according to the result of CHN, ATR-FTIR analyses and phosphate groups remained on the surface of nano titania

Summary

Introduction

Ethylenediaminetetraacetic acid (EDTA) is mainly used as acid and sodium salt extensively, in several industrial and domestic applications like photo and paper industry. Using EDTA prevents sedimentation and tarnishing of metal surfaces and intensifies the cleaning effect. Different products formulated to incorporate EDTA are distributed to a large number of outlets resulting in the disparate entry of EDTA in the aquatic environment.[1] The total application volume of EDTA as an ingredient of household detergents, cosmetics, pharmaceutical and food is released via the household sewage without elimination in treatment plants. The toxic effects of EDTA are considered to be related to metal deficiencies, especially a deficiency of zinc. It is well established that EDTA influences chromosome breakage by mutagenic agents, affects the inhibition of deoxyribonucleic acid (DNA) synthesis in primary cultures of mammalian cells and leads to morphological changes of chromatin and chromosome structure in plant and animal cells.[2] Removal of EDTA is not possible by biological treatment processes,[3]

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Conclusion