Adsorption studies with a new biosorbent Ensis siliqua shell powder for removal two textile dyes from aqueous solution

The presence of dyes in effluents is a long-standing problem and can cause considerable damage to the ecosystem of the receiving surface water resources. the development of efficient,relatively inexpensive and environmentally friendly natural adsorbent ensis siliqua shells was applied for the removal of two textile dyes,direct blue 71 (db71) and disperse red 60 (dr60),from aqueous solutions. the influence of solution ph,adsorbent dose,contact time,temperature and initial dye concentration on the adsorption process was studied. adsorption isotherm data were analyzed using the langmuir,temkin,freundlich and dubinin-radushkevich models. the freundlich isotherm was found to represent the measured sorption data well. kinetics of the adsorption reaction followed the pseudo second-order kinetic model. the maximum adsorption capacities at 25°c were 332.22 mg.g-1 and 384.29 mg.g-1 for dr60 and db71 respectively. various thermodynamic parameters such as δgo,δho and δso were calculated,indicating that this system was a spontaneous and endothermic process. © 2017,university of mohammed premier oujda morocco.