Comportamento do GCL permeado com biodisel

Abstract

The leakage of automotive fuels, such as biodiesel, in supply stations, reservoirs and transportation exposes the environment and human health to various harmful agents. In this sense, methods of retention of contaminants are necessary. This project aims to study the waterproofing efficiency over time of a barrier made up of a geosynthetic clay liner (GCL) when being permeated with biodiesel. A flexible wall permeameter was designed according to the American standard ASTM 5887, which maps the flow index measurement through a GCL sample. A study was carried out comparing the expansion of hydrated sodium bentonite with distilled water and biodiesel, observing the absence of expansion in the clay-mineral when hydrated with biodiesel and, thus, its lack of efficiency in this condition. For the hydraulic conductivity tests, a constant head rigid wall permeameter was used. The samples were hydrated with distilled water and then leached with pure biodiesel. The long-term effect was evaluated with flow measurements for more than three months of permeation with the contaminating fluid. The hydraulic conductivity had increase of permeability from the scale 10 −11 m/s to the scale 10 −9 m/s. It was observed, therefore, a decrease in the waterproofing capacity of the material over time and the presented behavior suggests the non-adequacy of the use of GCL in sites susceptible to biodiesel leaks.