ORIGINAL ARTICLES Channel Sediment Characterization and Evaluation of the Potential Impact of Iron-Rich Phases on the Use of Sediments in Brick Production Daniele Malferrari, 1 Angela Laurora, 1 Chiara Elmi, 1 Maria Franca Brigatti, 1, * Luca Medici, 2 and Maria Chiara Zeqireja 1 1 Earth Sciences Department, University of Modena and Reggio Emilia, Modena, Italy. 2 Institute of Methodologies for Environmental Analysis, National Research Council, Tito Scalo, Italy. Received: February 24, 2010 Accepted in revised form: March 22, 2012 Abstract Using data collected at both room temperature and higher temperatures, this study examined the mineralogy of, and iron coordination shell in, polluted sediments from drainage and irrigation channels. As a part of the study, mineralogical characteristics of iron phases of canal sediments were examined to determine if these sediments could be used in place of common clays for the production of bricks. While such use would reduce the impact of these wastes on the environment, an excess of iron in these sediments could affect some important features of bricks. Therefore, this study examined the oxidation state of iron as well as its structural location in the mineral matrix. X-ray powder diffraction, thermal analysis, and X-ray absorption spectroscopy were used to examine sediments and bricks manufactured from irrigation and drainage channels of the Po River region in northeast Italy. Results indicated that canal sediments can be used as row materials in clay brick production. In fact, the process temperature (950°C) that characterized brick production was similar to the temperature used for thermal treatment of polluted sediments in this study. Key words: channels, sediments, thermal treatment, bricks Introduction D rainage and irrigation channel beds must be dredged periodically to maintain the required water mass flow. Because dredged sediments, especially those from drainage channels in industrial areas, are often characterized by pollutant concentrations well above the acceptable limits stated in many international regulations, it is sometimes necessary to store the sediments as dangerous waste materi- als. Given the massive amount of sediments involved, the extremely high costs associated with dangerous waste stor- age, and the severe environmental impact these wastes can have, researchers have begun to study the possibility of re- cycling dredged sediments. To do so, however, the sediments must first be treated. European technical protocols on wastes (D.Lgs., 2006) give strict guidelines for the treatment of pol- luted materials dangerous to human health and for methods to reuse wastes without environmental harm. Thermal tech- nologies, which use temperatures similar to those used in brick production, are proposed for sediment treatment be- cause they are able to volatilize or destroy organic contami- nants and to fix inorganic pollutants, such as heavy metals, thus significantly reducing or completely removing their en- vironmental hazard (Malferrari et al., 2009). Using brick production to recycle contaminated sediments addresses two important environmental issues: the depletion of natural resources and the disposal of industrial wastes. Furthermore, the traditional clay-based materials used in brick production are heterogeneous products that can ac- commodate different inorganic wastes without significantly affecting the production process or the technical properties of final products (Malferrari et al., 2009; Caligaris et al., 2000; Romero et al., 2009). In the search for waste materials that can be used in brick making, researchers have assessed everything from sewage sludge ash (Weng et al., 2003; Lin et al., 2006), waterworks sludge (Samara et al., 2009), and natural stone wastes (Acchar et al., 2006; Menezes et al., 2005; Blanco Garcı `a et al., 2005), to fly and bottom ashes (Lin, 2006; Olgun et al., 2005; Balgaranova et al., 2003; Cheeseman et al., 2003), met- allurgical wastes (Vieira et al., 2006; Shih et al., 2004), and boron waste (Uslu and Arol, 2004). However, it is not just organic and inorganic pollutants that engender strong environmental concerns over the use of sediments in bricks. Sediments from drainage channels con- tain iron (Fe), which, depending on its oxidation, coordina- tion, and bonding conditions, can affect a fired product’s properties (e.g., color and hardness). Thus, a knowledge of the *Corresponding author: Earth Sciences Department, University of Modena and Reggio, Largo S. Eufemia 19, Modena 41121, Italy. Phone: + 39 59 2055805; Fax: + 39 59 2055887; E-mail: mariafranca .brigatti@unimore.it ENVIRONMENTAL ENGINEERING SCIENCE Volume 29, Number 9, 2012 ª Mary Ann Liebert, Inc. DOI: 10.1089/ees.2010.0060 840