Avaliação da ultrafiltração e da adsorção em carvão ativado no tratamento avançado de efluente de uma indústria de papel e celulose

Abstract

This study evaluated the ultrafiltration process and the adsorption process in activated carbon as alternatives in the advanced effluent treatment of a pulp and paper industry. The ultrafiltration process was performed in a bench system. Initially, the ideal operational conditions of flow velocity and operating pressure were determined. The results showed that Re 1653, corresponding to the flow rate of 96 L.h-1 and, at 1.5 bar pressure, were the best conditions for the ultrafiltration process. Subsequently, the membrane performance was evaluated for the removal of the pollutants in relation to permeate flux obtained under such conditions. The results indicated high efficiency of the UF process in the removal of TSS and turbidity with reduction of 93.77% and 92.30%, respectively. The adsorption process in activated carbon was carried out in batch. First, the reaction time to obtain the adsorption equilibrium and the optimum pH to the process were investigated. The results indicated that the minimum time required to obtain equilibrium was 30 minutes and the pH did not influence the process. After that, the adsorption isotherms were determined to the color and phenol parameters. The experimental data were then adjusted to the Langmuir and Freundlich models and showed a good fit for both models. Subsequently, the adsorption process was evaluated for the removal of the pollutants at pH 7, temperature of 40 ºC and contact time of one hour. The results showed a great potential of the adsorption process in activated carbon in the advanced treatment of paper and cellulose effluent, with removal of more than 90% for the parameters color, turbidity, COD, phenol, Abs254 and Abs280, being more efficient than the ultrafiltration process.