Biosorption of Heavy Metals Using Organic Waste from Tequila Processing

Abstract

In Mexico and in the world, the metallurgical, petroleum and chemical industries, among others, generate large amounts of pollutants, which when deposited in dams or discharged into rivers, ponds or directly into aquifers generate serious problems for the environment. Biosorption is the phenomenon of passive uptake of metal ions with non-living organic materials, known as biomass, which are generally industrial waste. Active uptake with live biomass is called bioaccumulation. Biosorption is based on the property of some types of inactive or dead biomass to uptake and accumulate these elements by different mechanisms. There are several mechanisms that explain the fixation and retention of metals by the biosorbent used: physical adsorption, ion exchange, complexation, chelation etc. In this work the behavior of three organic residues from the tequila production process at Tarimoro plant, the fiber or bagasse obtained from the must from tequila processing, agave leaves and solid tequila vinasse were evaluated. The tests were carried out by contacting the biomass with a solution containing metal cations such as Cu, Fe and Mn. The maximum adsorption capacity was obtained at a pH of 8 (98% copper adsorption) with agave fiber biomass at temperature of 25°C. The samples studied at temperatures of 25°C showed the lowest concentration values ​​of Cu2+ in residual solution. The adsorption process was found dependent on pH and time. The results obtained allow to affirm that organic wastes from the elaboration of tequila are a viable alternative as biomass in the bioremediation process of toxic heavy metals by a biosorption technique.