Incorporação de resíduo industrial de granito na impermeabilização da camada de base do aterro sanitário em Campina Grande-PB

Abstract

Waste production, especially the Municipal Solid Waste (MSW), has increased significantly in the last decades. Municipal waste landfills are complex systems with interrelated processes. It is necessary to consider all interdependences to precisely predict the MSW behavior. The waste deposited in municipal waste landfills can produce pollutants with a high concentration of complex components of chemical and biological degradation, that have the potential to contaminate the groundwater and affect superficial waters. Some municipal waste landfills use a bottom layer composed of three types of different materials. Bottom layers are necessary to control and isolate the landfill leachate from the environment around the landfill. However, this type of layer is expensive, a cheaper alternative to building bottom layers is using compacted soil layers. The soil found at the waste landfill in Campina Grande is mixed with bentonite which is an expansive absorbent clay, that diminishes the leachate circulation because this clay creates an impermeabilization gel and expenses the process. The industry of ornamental rocks, mainly those industry which produce granite, generate a huge quantity of waste in their industrial process. Practically all of this waste is not recicled and is disposed of at inappropriate locations, resulting in serious social and environmental problems. Therefore, the present thesis aims to analyze the technical viability utilization of waste from processing ornamental stones (granite) mixed with soil to municipal waste landfill bottom layer impermeabilization of municipal waste landfill in Campina Grande-PB. Initially, it was defined maximum and minimum values of percentage of mixture of waste from the waste of granite, and soil, and compaction water content. A factorial experimental design defined the number and the experiments. It was also realized experiments to geotechnical characterization, physicalchemical and mineralogical characterization. The mixture permeabilities were obtained following the specifications of Brazilian Standard NBR 14545/2000. The results showed that the natural soil is a silty clayey sand (SC), with a Plasticity Index (IP) of around 9.78% and an average specific weight of 25.94 kN.m-3. Optimum moisture of 13.58% and a maximum dry density of 18.00 kN.m-3 were obtained in the compaction test. Given the studies carried out, the feasibility of using granite waste to reduce the water permeability of the base layer or landfill in Campina Grande was observed. Minimum values of the permeability coefficient recommended by NBR 13896/97 can be obtained for the analyzed mixtures.