Application of plasma-sprayed TiO2 coatings for industrial (tannery) wastewater treatment

Abstract

Fine-structured photocatalytic TiO 2 coatings were deposited by atmospheric plasma spraying (APS) on austenitic stainless steel coupons. One commercial spray-dried nanostructured TiO 2 powder and five spray-dried powders obtained from suspensions containing mixtures of submicrometric and nanometric TiO 2 particles were used as feedstock materials. Coating microstructure and phase composition were characterised using FEG-SEM and XRD techniques. The photocatalytic activity of the coatings was determined by measuring the degradation of methylene blue dye in aqueous solution.The experimental data were observed to follow a pseudo-first-order kinetic. The kinetic constants displayed a clear relationship with coating anatase content. 2The photocatalytic decontamination capability of one of these APS coatings was subsequently investigated by treating an industrial tannery wastewater. The photocatalytic experiments with these TiO 2 coated coupons were carried out in a selfdesigned reactor. Partial degradation of the pollutants was observed, owing to a decrease in Total Organic Carbon (TOC), in addition to a significant decolouration effect, mainly relating to the removal of aromatic organic compounds typically present in tannery wastewater. The results demonstrate the potential use of plasma-sprayed photocatalytic TiO 2 coatings in tannery wastewater treatment.

Thermal-Sprayed Photocatalytic Coatings for Biocidal Applications: A Review

“…The photodegradation experiments of dextran and humic acid prove its potential in photodegradation of bio-organisms and protein under UV light irradiation, which is essential in photocatalytic disinfection. Additionally, M. C. Bordes prepared TiO 2 photocatalytic coatings by APS from different feedstocks (Ref 97 ). The feedstocks were obtained by spray drying suspensions of a nano- and a submicron-sized TiO 2 powder, with different solids contents and/or ratios of the nano- to submicron-sized particles.…”

Research into Morphology and Properties of TiO2 – NiAl Atmospheric Plasma Sprayed Coating

“…In optoelectronics and production of photovoltaics panels, as well as in chemical processing to neutralize NO x and SO x compounds, TiO 2 coatings are implemented [5,6,12,13,27]. Moreover, TiO 2 coatings with addition of NiAl can be sprayed on engine elements because of their resistance do high temperature oxidation and creep [3,5,12,13]. However, microstructure and properties of TiO 2 with addition of Al 2 O 3 powders are discussed in particular, as stated in the literature [11,16,20].…”

Overview on Green Titanium Nanoparticles Based on Plants: Synthesis, Potential Applications and Eco-Friendly Approach.

“…In Future the high demand for clean water will be increased by about one-third of its present state 49 .This is due to its crucial role for the production of electronic devices, pharmaceuticals, paints, foods, and other beverages [50][51][52] . Recent advances in nanotechnology and Nano engineering by use of nonabsorbents, promising in achieving good quality of water 53 , nanoparticle-enhanced filtration 54 , Nano catalysts 55 and bioactive nanomaterials 56 . Various nanoparticles have been successfully reported for water and wastewater treatment, such as zerovalent metal nanoparticles (silver nanoparticles, iron nanoparticles, zinc nanoparticles), metal oxide nanoparticles (titanium dioxide nanoparticles, iron oxide nanoparticles, zinc oxide nanoparticles), carbon nanotubes, and nanocomposites 57 .…”