Removal of Malachite Green and Congo Red Dyes from Water by Polyacrylonitrile Carbon Fibre Sorbents

The present work was aimed at evaluating the adsorption properties of malachite green and congo red dyes by polyacrylonitrile carbon fibre sorbents. The sorbents were activated and oxidized using potassium hydroxide and ammonium persulfate, respectively at mild conditions. Consequently, the sorbents were characterized for surface area, surface functional groups and thermal decomposition. The activated sorbent displayed a 18.8 mg/g (94 %) of malachite green removal at Co = 20 mg/L, while both modified sorbents showed a 17.5 mg/g (87.5 %) removal of congo red at the same concentration. All sorbents showed a rapid equilibrium of malachite green and congo red dyes in water. Also, the sorbents are somewhat tolerable against different solution pH conditions despite a slight change due to possible electrostatic interactions. Thus, the materials could be successfully employed to treat dyes-laden wastewater.