Dredged sediments as a resource for brick production: socio-economic and technological possibilities and barriers

In Flanders (Belgium), approximately 12 000 kton of dredged sediments has to find a destination every year. A possible application is the use of dredged sediments as a raw material in brick production. Despite the fact that several examples in neighboring countries show that this is application is feasible, some socio-economic and technical limitations interfere with the use of dredged materials in brick production in Flanders. In the present study, the limitations and barriers, from the consumers’ point of view were analyzed, based on a survey held in Flanders. The survey dealt with the risk perception of citizens with respect to environmental problems in general and (contaminated) sediments in particular and with their the willingness to pay for bricks produced from traditional raw materials (clay) and from dredged sediments. The Decree on Materials management considers dredged sediments as a secondary resource, that can be used as a resource for building materials as long as they comply with certain criteria. Technical problems, such as the dewatering of sediments, have been solved during the last few years, but the real valorization of dredged sediments in high-grade applications is still very limited. The survey indicated that consumers in Flanders are rather suspicious with respect to bricks produced from dredged sediments and their risk perception is mainly determined by the possibility of a bad bargain, the social acceptance of the product, the connotation with contaminated river sediments and personal characteristics such as flexibility and independence. The willingness to pay for bricks made from dredged sediments is mainly influenced by the age of the respondents, as well environmental awareness, and the respondents’ belief in their ability to influence environmental problems. More than 50% of the respondents indicated that they had insufficient knowledge on this topic, despite the fact that 60% of the respondents had a higher education degree. Sensitization and information of customers is of primary importance to make dredged-sediment-derived bricks a successful productstatus: publishe