7th Congress of Environmental Application of Advanced Oxidation Technologies (7ºEPOA) and 1st Iberoamerican Congress of Advanced Oxidation Technologies (1ºCIPOA)

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In Iberoamerican countries, more than 80 million people lack access to clean drinking water and 100 million people lack adequate sanitation. This requires a tremendous amount of research to develop appropriate technologies and infrastructure to improve the community socioeconomic situation and protect human health, in agreement with the UN Millennium Development Goals. As reported in the “Workshop on Nanotechnologies for Environmental Remediation” (Rickerby and Morrison 2007), the development of photocatalytic depollution technologies that use solar energy, or even artificial light, can provide sustainable solutions for the production of clean and safe water in developed and developing countries. In particular, such solutions can be very beneficial for remote and isolated communities with insufficient infrastructure but leaving in locations of high yearly sunshine.

Despite its great potential as a green technology for water purification, TiO2 photocatalysis has not yet reached a mature level for large-scale applications.

Publications on solar-driven photocatalytic processes increased continuously during the last 10 years, achieving more than 2,000 papers in 2013, representing more than 50 % of the publications regarding photocatalysis (Fig. 1).

Fig. 1
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Number of publications concerning photocatalysis and solar-driven photocatalysis per year: SCOPUS search results in the period 2000–2013 (keywords: “Photocatalysis” and “Solar” within these results)

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Publications are divided into articles (10,510), conference papers (1,064), reviews (468), and others (53). Approximately 38 % of the articles regarding solar photocatalysis are from China (Fig. 2).

Fig. 2
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Number of articles concerning solar-driven photocatalysis per country: SCOPUS search results in the period 2000–2013 (keywords: “Photocatalysis” and “Solar” within these results)

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Although Iberoamerican countries are among the sunniest countries in the world and have serious water scarcity problems, they have only contributed to 10 % of the articles published, with 46 % being from Spain (Fig. 3).

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Number of articles concerning solar-driven photocatalysis per Iberoamerican country: SCOPUS search results in the period 2000–2013 (keywords: “Photocatalysis” and “Solar” within these results)

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This special issue of Environmental Science and Pollution Research contains a selection of 20 papers presented at the 7th Congress of Environmental Application of Advanced Oxidation Technologies (7°EPOA) and the 1st Iberoamerican Congress of Advanced Oxidation Technologies (1°CIPOA), which were held in Recife, Brazil, from 15 to 18 October 2013.

The goal of CIPOA conferences was to provide a platform to spread the knowledge in advanced oxidation processes around the Iberoamerican countries and attract new young researchers to this research field.

The 7°EPOA and 1°CIPOA meetings brought together more than 200 academics, professionals, and policy makers from different Iberoamerican countries such as Brazil, Spain, Portugal, Argentina, Mexico, Colombia, Uruguay, Chile, and Peru. In addition, researchers from France, Germany, Switzerland, Canada, and the USA also attended the meetings. The conference program was rather dense and rich, offering a considerable variety of topics covered, with 12 keynotes, 80 oral presentations, 74 short oral communications, and 70 posters. The short oral communications gave the opportunity to young researchers to present their research work and to interact with senior researchers. The topics covered included (i) new photocatalytic materials; (ii) environmental remediation of water, wastewater, air, and soil, using different advanced oxidation technologies; and (iii) integration of AOPs with other technologies, such as biological oxidation, adsorption, coagulation/flocculation, and membranes.

Several papers selected from the scientific presentations of 7°EPOA/1°CIPOA outline new materials (N-modified titania nanotubes, TiO2/Ag, TiO2-activated carbon) with remarkable photocatalytic activity for the degradation of different organic pollutants in water and air. The classical heterogeneous and homogeneous Fenton, photo-Fenton, and solar driven photo-Fenton processes, catalyzed by ferrous iron, ferric iron, zero-valent iron, or iron oxides, such as goethite, montmorillonite clay modified with iron, Fe particles dispersed in a carbon matrix active, iron oxide pillared clay with magnetic properties, mixed material clay/Fe, and siderurgical iron sludges, were also evaluated for remediation processes. Two papers also deal with reaction pathways and kinetic modelling, and another two papers use ultrasonic and ozonation processes.

This special issue also provides an overview of some photocatalytic water/air depollution systems that utilize solar energy and could be used in remote areas not reached from the grid, as well as photocatalytic applications and challenges in Iberoamerican countries.

The guest editors would like to thank all the authors for the innovative scientific contributions to this special issue, the reviewers whose comments and suggestions were extremely important to achieve high-quality papers, as well as the institutions and companies that sponsored 7°EPOA/1°CIPOA.

A final word of thanks to ESPR editor-in-chief Philippe Garrigues and the editorial assistant Emmanuelle Pignard-Péguet for their assistance/help/support in the preparation of this special issue.

Vítor Vilar wishes to thank the FCT Investigator 2013 Programme (IF/01501/2013). Sixto Malato wishes to thank the Spanish Ministry of Economy and Competitiveness financial support under the AQUAFOTOX Project (Reference: CTQ2012-38754-C03-01). Dionysios Dionysiou also acknowledges support from the University of Cincinnati through a UNESCO co-chair professor position on “Water Access and Sustainability.”