PRODUÇÃO DE ADOBE COM BIOMASSA DE MACRÓFITAS AQUÁTICAS: UMA ALTERNATIVA PARA RETIRADA E ENCAPSULAMENTO DE POLUENTES DE LAGOS E RESERVATÓRIOS

Abstract

This work intends to optimize the utilization of aquatic macrophyte biomass in the adobe (a sun-dried mud brick) production, based on the study of the physical and mechanical characteristics ofthese bricks and the macrophytes biomass estimate as well as their chemical characteristics. Theresearch was developed in the Salto Grande Reservoir region, in Americana (a town in São Paulostate, Brazil). This lake is located in an area of high urbanization and industrialization level, withcommon dwelling deficit, which is in advanced artificial eutrophication process by human activityaction. The aquatic macrophytes found in that place (Brachiaria arrecta, Eichhornia crassipesandPistia stratiotes) present a high level of heavy metals and nutrients that make impracticable theirutilization as forage or fertilizer. The biomass utilization in the construction of materials appears hereas an alternative of integrated management of the lake in the stabilization/solidification (or“encapsulation”) of these chemical substances, in addition to the fact that it makes possible the self-building of low cost dwellings. The other biomass function is to stabilize the soil that has a high clayconcentration (59%, with 21% silt and 20% sandy) and would suffer a large drawing back during thedrying process, with the introduction of excessive fissures. This biomass addition was made toreduce these fissures and the specific mass of the bricks. Besides, the research results show that,even though the adobe bricks are perhaps the oldest manufactured building material, their applicationpersists practicable mainly in the sustainability hopes for being a completely ecological buildingmaterial and adequate for the tropical regions.