Titania nano-coated quartz wool for the photocatalytic mineralisation of emerging organic contaminants

Abstract

Many emerging contaminants pass through conventional wastewater treatment plants, contaminating surface and drinking water. The implementation of advanced oxidation processes in existing plants for emerging contaminant remediation is one of the challenges for the enhancement of water quality in the industrialised countries. This paper reports on the production of a TiO 2 nano-layer on quartz wool in a relevant amount, its characterisation by X-ray diffraction and scanning electron microscopy, and its use as a photocatalyst under ultraviolet radiation for the simultaneous mineralisation of five emerging organic contaminants (benzophenone-3, benzophenone-4, carbamazepine, diclofenac, and triton X-100) dissolved in deionised water and tap water. This treatment was compared with direct ultraviolet photolysis and with photocatalytic degradation on commercial TiO 2 micropearls. The disappearance of every pollutant was measured by high performance liquid chromatography and mineralisation was assessed by the determination of total organic carbon. After 4 hours of treatment with the TiO 2 nano-coated quartz wool, the mineralisation exceeds 90% in deionised water and is about 70% in tap water. This catalyst was reused for seven cycles without significant efficiency loss.

Current Trends in the Application of Nanomaterials for the Removal of Emerging Micropollutants and Pathogens from Water

“…The simultaneous mineralization of five emerging organic contaminants, which were dissolved in deionized and tap water was performed by UV-photocatalytic degradation on commercial TiO 2 micropearls and this was compared against TiO 2 nanolayer on quartz wool. The extent of mineralization exceeded 90% in deionized water and was approximately 70% in tap water after 4 h of treatment, while the catalyst was reused for seven cycles without significant efficiency loss [114]. Xu et al reported that TiO 2 nanowires on flexible PET fabrics were found to possess higher photocatalytic activity towards degradation of rhodamine B in water under UV light than either TiO 2 nanotube array or commercial P25 TiO 2 nanoparticulate films on metallic Ti substrates.…”

Stability and Removal of Benzophenone-Type UV Filters from Water Matrices by Advanced Oxidation Processes

“…Details about photocatalytic experiments are presented in Table 3. Saracino [72] evaluated the possibility of producing large batches of photocatalyst nano-layers, immobilized on a high-surface-area soiled substrate and their application for the removal of various emerging organic contaminants (among them BP-3 and BP-4).…”

“…Saracino [ 72 ] evaluated the possibility of producing large batches of photocatalyst nano-layers, immobilized on a high-surface-area soiled substrate and their application for the removal of various emerging organic contaminants (among them BP-3 and BP-4). Increasing the amount of catalyst, in general, leads to an increased efficacy rate of the degradation of pollutants.…”

“…According to Zúñiga–Benítez [ 74 ] analysis, the kinetics of degradation of BP-3 in the concentration range 0.5–2.0 mg/L are first order and at higher initial concentrations a deviation from first-order kinetics occurs. Since BP-3 concentration in natural waters has been reported in levels around ng/L, it can be assumed that the pollutants photocatalytic degradation in environmental water bodies, follows the first-order kinetics [ 72 ]. Table 3 shows an overview of the photocatalytic reactions used in the degradation reaction of BPs with the stress on optimal conditions of the reaction and photodegradation efficacy obtained.…”

Emerging pollutants—Part II: Treatment

“…Specifically, after six runs, the removal rate of norfloxacin by BFZ and UDZ was 70% and 4%, respectively. Saracino et al (2018) synthesized titania nano-coated quartz wool (TNCQW) by the sol-gel method and investigated the possibility of simultaneous mineralization of five emerging organic pollutants under ultraviolet light using TNCQW as photocatalyst. Five selected pollutants included benzophenone-3, benzophenone-4, carbamazepine, diclofenac, and Triton X-100.…”