Adsorption efficiency of kaolinite to remove Direct Red 13, toxic andanionic bisazo dye, from aqueous solution has been attempted. The parameters tested and conditions optimized included initial concentration of DR13 (100 mg/L), agitation period (180 min), adsorbent dose (0.300 g/L), pH 7 as well as temperature (303K, 313K, 323K). Adsorption data were evaluated by using such isothermal models as Langmuir, Freundlich and Temkin. High correlation coefficient (R2 ) was observed only with the Langmuir isotherm, and the monolayer adsorption capacity (Qm) observed was7.5 mg/g. Kinetic data has good agreement with pseudo-first order model. Fraction Factorial Experimental Design (FFED) and the analysis of variance (ANOVA) indicated maximum adsorption of 85 mg/g of the dye on the kaolinite. It was suggested that kaolinite can be used as lowcost adsorbent for DR13 removal from wastewate
