Materials 2015, 8, 96-116; doi:10.3390/ma8010096 OPEN ACCESS materials ISSN 1996-1944 www.mdpi.com/journal/materials Article Adsorption of C.I. Natural Red 4 onto Spongin Skeleton of Marine Demosponge Małgorzata Norman 1, Przemysław Bartczak 1, Jakub Zdarta 1, Włodzimierz Tylus 2, Tomasz Szatkowski 1, Allison L. Stelling 3, Hermann Ehrlich 4 and Teofil Jesionowski 1,* 1 Institute of Chemical Technology and Engineering, Faculty of Chemical Technology, Poznan University of Technology, Berdychowo 4, Poznan 60965, Poland; E-Mails:
[email protected] (M.N.);
[email protected] (P.B.);
[email protected] (J.Z.);
[email protected] (T.S.) 2 Institute of Inorganic Technology and Mineral Fertilizers, Technical University of Wroclaw, Smoluchowskiego 25, Wroclaw 50372, Poland; E-Mail:
[email protected] 3 Department of Mechanical Engineering and Materials Science, Center for Materials Genomics, Duke University, 144 Hudson Hall, Durham, NC 27708, USA; E-Mail:
[email protected] 4 Institute of Experimental Physics, Technische Universität Bergakademie Freiberg, Leipziger 23, Freiberg 09599, Germany; E-Mail:
[email protected] * Author to whom correspondence should be addressed; E-Mail:
[email protected]; Tel.: +48-61-665-3720; Fax: +48-61-665-3649. Academic Editor: Harold Freeman Received: 31 August 2014 / Accepted: 18 December 2014 / Published: 29 December 2014 Abstract: C.I. Natural Red 4 dye, also known as carmine or cochineal, was adsorbed onto the surface of spongin-based fibrous skeleton of Hippospongia communis marine demosponge for the first time. The influence of the initial concentration of dye, the contact time, and the pH of the solution on the adsorption process was investigated.