Industrial steel waste recovery pathway: Production of innovative supported catalyst and its application on hexavalent chromium reduction studies.

Mill scale is the metallurgical waste produced by the rolling mill in the steel hot rolling process. This hazardous waste is mainly composed of oxide iron, such as hematite, magnetite and wustite. It may have a different and alternative final destination by becoming a catalyst for wastewater treatment.

Facile fabrication of hybrid titanium(IV) isopropoxide/pozzolan nanosheets (TnS-Pz) of high photocatalytic activity: characterization and application for Cr(VI) reduction in an aqueous solution.

This paper presents the synthesis of a hybrid material through the use of natural pozzolan and titanium(IV) isopropoxide using the sol-gel method and its application in the photocatalytic hexavalent chromium reduction. The characterization data indicated a mesoporous material possessing a surface area of 271.7 m g.

As(III) and Cr(VI) oxyanion removal from water by advanced oxidation/reduction processes-a review.

Water pollution by human activities is a global environmental problem that requires innovative solutions. Arsenic and chromium oxyanions are toxic compounds, introduced in the environment by both natural and anthropogenic activities. In this review, the speciation diagrams of arsenic and chromium oxyanions in aqueous solutions and the analytical methods used for their detection and quantification are presented.

Application of a micro-meso-structured reactor (NETmix) to promote photochemical UVC/HO processes - oxidation of As(iii) to As(v).

A micro-meso-structured reactor (NETmix) was used for the first time to promote photochemical UVC/H2O2 processes. The NETmix photoreactor consists of a network of chambers and channels, where the liquid flows, sealed with a quartz slab with high UVC transparency. Due to the small size of channels and chambers, the NETmix presents a uniform irradiance through the entire reactor depth, short molecular diffusion distances and large specific interfacial areas, maximizing the pollutant/oxidant contact.

Strategies to reduce mass and photons transfer limitations in heterogeneous photocatalytic processes: Hexavalent chromium reduction studies.

The current work presents different approaches to overcome mass and photon transfer limitations in heterogeneous photocatalytic processes applied to the reduction of hexavalent chromium to its trivalent form in the presence of a sacrificial agent. Two reactor designs were tested, a monolithic tubular photoreactor (MTP) and a micro-meso-structured photoreactor (NETmix), both presenting a high catalyst surface area per reaction liquid volume. In order to reduce photon transfer limitations, the tubular photoreactor was packed with transparent cellulose acetate monolithic structures (CAM) coated with the catalyst by a dip-coating method.

Photo-Fenton oxidation of 3-amino-5-methylisoxazole: a by-product from biological breakdown of some pharmaceutical compounds.

The present study aims to assess the removal of 3-amino-5-methylisoxazole (AMI), a recalcitrant by-product resulting from the biological breakdown of some pharmaceuticals, applying a solar photo-Fenton process assisted by ferrioxalate complexes (SPFF) (Fe/HO/oxalic acid/UVA-Vis) and classical solar photo-Fenton process (SPF) (Fe/HO/UVA-Vis). The oxidation ability of SPFF was evaluated at different iron/oxalate molar ratios (1:3, 1:6, and 1:9, with [total iron] = 3.58 × 10 mM and [oxalic acid] = 1.

TiO2 and ZnO mediated photocatalytic degradation of E2 and EE2 estrogens.

In this work, the photocatalytic degradation of selected estrogens (E2 and EE2) was evaluated, using bench-scale and continuous treatment systems assisted by artificial UV-A and solar radiation. Processes based on the use of TiO2 permit an efficient degradation of E2 and EE2 estrogens, usually at reaction times lower than 15 min. Especially remarkable is the high degradation efficiency shown by sunlight-assisted processes, which are extremely favored by the high efficiency of compound parabolic collectors.