Adsorption of Cationic and Anionic Dyes from Aqueous Solution Using Sunflower Husk

The current study deals with the removal of cationic dye (brilliant green) and anionic dye (methyl orange) from wastewater by using sunflower husk as an adsorbent. The operation takes place batch wise by applying several concentrations of the dye solution with various adsorbent amounts, at a range of initial PH values and particle sizes at varying contact time intervals. The percent of dye removed for two dyes increased with increasing time and adsorbent dose and decreased with increasing the dye concentration and particle size. The equilibrium time differed according to conditions used. The optimum removal for brilliant green dye was 98 %, which was achieved at 50 ppm dye concentration, 2 g\l adsorbent dose, 75 µm particles size and pH 7 at contact time of 1 h, compared with low removal for methyl orange that reached 54 % under optimum conditions (dye concentration 10 ppm, adsorbent dose 4 g/l, pH 3 at the same particles size and time). Kinetic studies were conducted and revealed that the adsorption was well defined by pseudo-second order model and could be described by the Langmuir isotherm.