Evaluation of sisal fiber drying kinetics and fiber use in synthetic textile dye adsorption

Agroindustrial waste is a low cost alternative material and has great potential as a pollutant adsorbent. Based on this principle, the present study evaluated the potential of sisal fiber as a textile dye adsorbent. Prior to the adsorption tests, drying kinetics studies of the sisal fiber were performed at temperatures of 60 degrees C and 80 degrees C. At the time, the shortest drying balance time was reached in 180 min at 80 degrees C. In order to achieve better results, the drying data were adjusted to Page, Henderson and Pabis, Newton O'Callaghan, Logarithmic and Midilli models. The results showed that the Midilli model was the most suitable for the process at both temperatures. As for the adsorption tests, they were performed in a finite bath in which 25 ml of the dye solution, 0.25 g of sisal fiber and agitation of 120 rpm were used. In the adsorption study, a 2(3) factorial design was applied to evaluate the influence of dye concentration, drying temperature and contact time on the adsorption process. The results of the statistical analysis of the 2(3) factorial design showed that all control variables studied influence the adsorption process. The highest values of the variables q (mg.g(-1)) and Removal (%) were 3.23 mg.g(-1) and 64.52 % respectively. From the significant effects, it was possible to conceive empirical models for the dependent variables, since all presented statistical significance for a confidence level of 95 %. The determination coefficients for the empirical models were 99.64 % and 96.44 % respectively. In view of the results obtained, the sisal fibers proved to be an excellent alternative adsorbent, for the treatment of wastewater, containing textile dye.