Abstract
Effluents containing metals may come from different types of industries, including paper mills, petrochemical plants, inorganic reagents and fertilizers, petroleum refining, steel foundries and metal working, textile mills, leather tanning, and others. These industries produce large volumes of wastewater requiring efficient and low-cost treatment. Pequi (Caryocar brasiliense Camb.) is a fruit native to the Brazilian cerrado, and its skin, which represents about 60% by weight of the fruit, is often overlooked during processing. In this work, pequi skins were used as biosorbent material in solutions containing chromium, lead, and cadmium. Factors such as biomass dose, pH, and biomass size were studied using a factorial statistical design. The results showed that the metal with the highest biosorption in the biomass was lead, with an average biosorption of 16.78 mg.g-1 and up to 80% removal of the solution, while there was less removal of chromium and cadmium. The dose of biomass and pH were found to be the most important factors in the biosorption. The grain size, on the other hand, generally did not influence the adsorption and can be discounted among the factors that act in the process.