8/3/2019 Cecchin-Bosicon

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Application of Soil Washing modified mining waste contaminated with diesel

Brazil is one of the world's richest countries and the availability of natural

resources in the world with an immense biodiversity and one of the largest reservoir of

fresh water. Among these treasures, there are the reserves for the extraction of precious

stones, with Brazil being one of the largest exporters in the world generating billions of

raw material for the economy. In contrast, the effects of the mining process are

responsible for a severe degradation of the natural environment, it is evident that the

intense extraction of minerals and precious stones end up generating socio-

environmental conflicts, due to outdated methodologies and economic interests

involved. One of the residues resulting from this process is a material composed of rock

dust in emulsified diesel holding a pasty appearance and classified as Class I Waste -

Hazardous. The objective of this work is the optimization of a system adapted to

washing soil (Soil Washing) for removal of existing pollutant load in the solid generated

in the process of improvement of agate geodes. The contaminated residue was subjectedto a battery of tests with solutions of sodium hydroxide prepared at concentrations of 0,

0.175, 0.35 mol / L. After preparation, the solution was placed in a beaker containing

6O Brazil is one of the world's richest countries and the availability of natural resources

in the world with an immense biodiversity and one of the largest reservoir of fresh

water. Among these treasures, there are the reserves for the extraction of precious

stones, with Brazil being one of the largest exporters in the world generating billions of

raw material for the economy. In contrast, the effects of the mining process are

responsible for a severe degradation of the natural environment, it is evident that the

intense extraction of minerals and precious stones end up generating socio-

environmental conflicts, due to outdated methodologies and economic interestsinvolved. One of the residues resulting from this process is a material composed of rock

dust in emulsified diesel holding a pasty appearance and classified as Class I Waste -

Hazardous. The objective of this work is the optimization of a system adapted to

washing soil (Soil Washing) 0 grams of the sample, obtaining a relative waste solution

in the ratio 7:3. For the treatment of waste used to predetermined temperatures of 20, 50

and 80 C with shaking time of 15 minutes ending with a sedimentation of 24 hours.

The content of diesel fuel in existing residual solid sedimented was quantified with the

help of Soxhlet equipment and later made the processing of data to statistical software.

During the tests it was noted a high influence of temperature and sodium hydroxide, by

the interpolation of the data obtained in a removal surface response in statistical

software. It is concluded from the analysis of the surface obtained that the optimum

temperature for the technique used is around 60 C and the molarity of sodium

hydroxide was found ideal of 0.22 mol / L, achieving a removal efficiency greater than

95% of the contaminant.

Key-word: Diesel, Remediation, Agate Geode.