Ronaldo Ferreira do Nascimento is Professor at Federal University of Ceará (UFC), Brazil. He received his Ph.D. in Analytical Chemistry from Universidade de São Paulo (USP), Brazil, in 1997. He has experience in the field of analytical chemistry, with emphasis on the development of separation methods (gas chromatography and liquid chromatography), environmental chemistry (trace analysis) and adsorption (removal of pollutants from aqueous effluents using natural adsorbents).    Vicente de Oliveira Sousa Neto is Professor in the Faculty of Education, Sciences, and Letters (FECLESC) at the State University of Ceará (UECE), Brazil. He received his Ph.D. in Civil Engineering in the area of environmental sanitation by the Federal University of Ceará in 2012. He has experience in the area of environmental chemistry, with an emphasis on bioadsorption (treatment of wastewater using modified bioadsorbents and low cost), and chemistry of materials with emphasis on development of thin films for photovoltaics.   Pierre Fechine is Professor at Federal University of Ceará (UFC), Brazil, and has previously served as Head of the Department of Analytical Chemistry and Physical Chemistry. Prof. Fechine is a member of the Brazilian Academy of Sciences. He has experience in the field of chemistry, with emphasis on inorganic chemistry, working mainly in the following subjects: chemistry of materials, condensed state physics, dielectric and magnetic properties, biomaterials and nanoparticles.   Paulo T. C. Freire is Professor at the Federal University of Ceará (UFC), and has previously served as Head of the Department of Physics and Dean of the Science Faculty at UFC. He received his Ph.D. in Physics from Universidade Estadual de Campinas in 1995. He has experience in the field of physics, with emphasis on Raman spectroscopy, nanomaterials, organic materials and high-pressure properties.