Natural magnetite as an effective and long-lasting catalyst for CWPO of azole pesticides in a continuous up-flow fixed-bed reactor.

The global occurrence of micropollutants in water bodies has raised concerns about potential negative effects on aquatic ecosystems and human health. EU regulations to mitigate such widespread pollution have already been implemented and are expected to become increasingly stringent in the next few years. Catalytic wet peroxide oxidation (CWPO) has proved to be a promising alternative for micropollutant removal from water, but most studies were performed in batch mode, often involving complex, expensive, and hardly recoverable catalysts, that are prone to deactivation.

Photo-Fenton oxidation of cylindrospermopsin at neutral pH with LEDs.

Cylindrospermopsin (CYN) is a potent cyanobacterial toxin found in freshwaters worldwide. In this work, the feasibility of the photo-Fenton process under neutral pH using light emitting diodes as irradiation source for the removal of this hazardous cyanotoxin from freshwater was investigated. The impact of the kind of iron chelating agent (ethylenediamine-N, N'-disuccinic acid vs.

Insights into the degradation of microplastics by Fenton oxidation: From surface modification to mineralization.

This work aims at evaluating the fate of microplastics (MPs) along Fenton oxidation. For such goal, realistic MPs (150-250 μm) of five representative polymer types (PET, PE, PVC, PP and EPS) were obtained from commercial plastic products by cryogenic milling. Experiments (7.

Adsorption of micropollutants onto realistic microplastics: Role of microplastic nature, size, age, and NOM fouling.

This work aims at evaluating the role of nature, size, age, and natural organic matter (NOM) fouling of realistic microplastics (MPs) on the adsorption of two persistent micropollutants (diclofenac (DCF) and metronidazole (MNZ)). For such goal, four representative polymer types (polystyrene (PS), polyethylene terephthalate (PET), polypropylene (PP) and high-density polyethylene (HDPE)) were tested. MPs were obtained by cryogenic milling of different commercial materials (disposable bottles, containers, and trays), and fully characterized (optical microscopic and SEM images, FTIR, elemental analysis, water contact angle and pH).

A comparative study among catalytic wet air oxidation, Fenton, and Photo-Fenton technologies for the on-site treatment of hospital wastewater.

The feasibility of catalytic wet air oxidation, intensified homogeneous Fenton and heterogeneous Photo-Fenton systems for the treatment of real hospital wastewater has been investigated. Wastewater samples were collected from a hospital sewer, during a weekly monitoring program, and fully characterized. Up to seventy-nine pharmaceuticals, including mostly parent compounds and some of their transformation products, were analyzed.

Overview of toxic cyanobacteria and cyanotoxins in Ibero-American freshwaters: Challenges for risk management and opportunities for removal by advanced technologies.

The increasing occurrence of cyanobacterial blooms worldwide represents an important threat for both the environment and public health. In this context, the development of risk analysis and management tools as well as sustainable and cost-effective treatment processes is essential. The research project TALGENTOX, funded by the Ibero-American Science and Technology Program for Development (CYTED-2019), aims to address this ambitious challenge in countries with different environmental and social conditions within the Ibero-American context.

Degradation of widespread cyanotoxins with high impact in drinking water (microcystins, cylindrospermopsin, anatoxin-a and saxitoxin) by CWPO.

The occurrence of harmful cyanobacterial blooms has unabated increased over the last few decades, posing a significant risk for public health. In this work, we investigate the feasibility of catalytic wet peroxide oxidation (CWPO) promoted by modified natural magnetite (FeO-R400/HO), as an inexpensive, simple-operation and environmentally-friendly process for the removal of the cyanotoxins that show the major impact on drinking water: microcystins (MC-LR and MC-RR), cylindrospermopsin (CYN), anatoxin-a (ATX) and saxitoxin (STX). The performance of the system was evaluated under ambient conditions and circumneutral pH (pH = 5) using relevant cyanotoxin concentrations (100-500 μg L).

Fast degradation of diclofenac by catalytic hydrodechlorination.

Aqueous-phase catalytic hydrodechlorination (HDC) has been scarcely explored in the literature for the removal of chlorinated micropollutants. The aim of this work is to prove the feasibility of this technology for the fast and environmentally-friendly degradation of such kind of compounds. Diclofenac (DCF), a highly consumed anti-inflammatory drug, has been selected as the target pollutant given its toxicity and low biodegradability.

Boosting the catalytic activity of natural magnetite for wet peroxide oxidation.

This work explores the modification of naturally occurring magnetite by controlled oxidation (200-400 °C, air atmosphere) and reduction (300-600 °C, H atmosphere) treatments with the aim of boosting its activity in CWPO. The resulting materials were fully characterized by XRD, XPS, TGA, TPR, SEM, and magnetization measurements, allowing to confirm the development of core-shell type structures. The magnetite core of the solid remained unchanged upon the treatment whereas the Fe(II)/Fe(III) ratio of the shell was modified (e.

Kinetics of imidazolium-based ionic liquids degradation in aqueous solution by Fenton oxidation.

In the last few years, several works dealing with Fenton oxidation of ionic liquids (ILs) have proved the capability of this technology for their degradation, achieving complete ILs removal and non-toxic effluents. Nevertheless, very little is known about the kinetics of this process, crucial for its potential application. In this work, the effect of several operating conditions, including reaction temperature (50-90 °C), catalyst load (10-50 mg L Fe), initial IL concentration (100-2000 mg L), and hydrogen peroxide dose (10-200% of the stoichiometric amount for the complete IL mineralization) on 1-butyl-3-methylimidazolium chloride ([Cmim]Cl) oxidation has been investigated.

Application of CWPO to the treatment of pharmaceutical emerging pollutants in different water matrices with a ferromagnetic catalyst.

CWPO has proved to be effective for the treatment of representative pharmaceuticals (sulfamethoxazole, atenolol, metronidazole, diltiazem, trimethoprim and ranitidine) in different water matrices (ultrapure water, surface water, WWTP effluent and hospital wastewater). Complete removal of the pollutants and the aromatic intermediates was achieved using the stoichiometric dose of HO, a catalyst (FeO/γ-AlO) load of 2gL, pH 3 and temperature of 50-75°C. Accordingly, the ecotoxicity was reduced to negligible values.

Application of intensified Fenton oxidation to the treatment of sawmill wastewater.

The application of the Fenton process for the treatment of sawmill wastewater has been investigated. The sawmill wastewater was characterized by a moderate COD load (≈3gL(-1)), high ecotoxicity (≈ 40 toxicity units) and almost negligible BOD/COD ratio (5×10(-3)) due to the presence of different fungicides such as propiconazole and 3-iodo-2-propynyl butyl carbamate, being the wastewater classified as non-biodegradable. The effect of the key Fenton variables (temperature (50-120°C), catalyst concentration (25-100 mg L(-1) Fe(3+)), H2O2 dose (1 and 2 times the stoichiometric dose) and the mode of H2O2 addition) on COD reduction and mineralization was investigated in order to fulfill the allowable local limits for industrial wastewater discharge and achieve an efficient consumption of H2O2 in short reaction times (1h).

Chlorophenols breakdown by a sequential hydrodechlorination-oxidation treatment with a magnetic Pd-Fe/γ-Al2O3 catalyst.

Degradation of chlorophenols by a sequential combination of hydrodechlorination (HDC) and catalytic wet peroxide oxidation (CWPO) using a new magnetic Pd-Fe/γ-Al2O3 catalyst has been studied. This catalyst is active in both hydrodechlorination of chlorophenols and decomposition of H2O2 for the oxidation of organic compounds. The sequential combination of HDC and CWPO allows overcoming some of the drawbacks of both treatments applied independently.

Assessment of the generation of chlorinated byproducts upon Fenton-like oxidation of chlorophenols at different conditions.

Homogeneous Fenton-like (H(2)O(2)/Fe(3+)) oxidation proved to be highly efficient in the degradation of monochlorophenols but some important issues need to be considered depending on the operating conditions. When using the stoichiometric amount of H(2)O(2) and a dose of Fe(3+) in the range of 10-20mg/L, complete breakdown of 4-CP up to CO(2) and short-chain acids was achieved. Nevertheless, when substoichiometric amounts of H(2)O(2) or lower concentrations of iron were used, significant differences between the TOC measured and the calculated from the identified species were found.