ADSORPTION CHARACTERISTICS OF SACFs FORA VARIETY OF DYES

The isothermal adsorption of dyes on a variety of sisal based activated carbon fibers (SACFs),and the influence of pH and temperature on adsorption are discussed in this paper.The results indicate that the adsorption of methylene blue,crystal violet and Eriochrome blue black R on SACFs shows type I isotherms and can be described by the Langmuir equation or the Freudlich equation.The acidity of solution has greatly influence over the adsorption amounts of methylene blue,crystal violet and Eriochrome blue black R.As pHs of the solutions were adjusted to increase or decrease from the original acidity of the solution(4.7,4.1 and 4.0 for methylene blue,crystal violet and Eriochrome blue black R,respectively),the amounts of dyes adsorbed on SACFs increased.The adsorption temperature(in the range of 25-50℃) exerts little influence on the adsorption amount of methylene blue,crystal violet and fluorescein.For azo dyes (Eriochrome blue black R and Eriochrome black T),however,the adsorption amount increases slightly with the elevation of temperature.