Cashew bagasse agricultural residue as adsorbent in the removal of toluene from the mixture oil and water

Abstract

Improper disposal of contaminated water into the environment has caused serious environmental problems for water bodies and soils. In order to reduce this problem, laws were created imposing limits on the amount of substances present in water before being discharged into the environment. Toluene has a very high pollutant potential due to its flammable, toxic and carcinogenic properties and even low concentrations need to be treated before disposal or reuse. Among the techniques offered for wastewater treatment, adsorption, using agricultural materials, stands out, which besides promoting a high percentage of removal has a low cost and high biodegradability. In this sense, this work aimed to evaluate the efficiency of cashew bagasse as a natural adsorbent for the removal of toluene in aqueous solution. The tests were performed in batch. Cashew bagasse dissolved substances that interfered with reading on the spectrophotometer. For this reason, a preliminary study was performed, resulting in a corrective method that disregards the interference of bagasse in the reading of the concentration of aliquots. The results showed a 77% removal. It was also observed that the removal percentage was higher for tests with higher initial solution concentration. The experimental data were better suited to Langmuir adsorption model and with maximum adsorption capacity of 49.02 mg toluene.g-1 of bagasse.