Decolorization of Reactive Red 198 by means ofpistachio-nut shell ash

Reactive dyes have extensively been used in textile industries during last year''s due to their superior performance، but the effluence of the waste containing such dyes into water resources can pose hazardous effects on the environment and to the human health because of their carcinogenic، mutagenic، allergenic and toxic nature. The present research was performed to study the efficiency of pistachio-nut shell ash in removing Reactive Red 198 dye from aqueous solutions. In the present experimental study، effects of various operating parameters such as initial concentration of dye (20-200 mg/L)، contact time (5-270 mines)، adsorbent dosage (0. 1-5 g/L) and pH (2-12) were investigated. Maximum adsorption capacity of the pistachio-nut shell ash was 238. 1 mg/g at pH 2، contact time 60 minutes and adsorbent dosage 0. 3 g/L. Besides، the equilibrium data were also fitted into the Langmuir and Freundlich equilibrium isotherm models. It was found that the data fitted into Freundlich (R2=0. 9352) model in a better extent than into Langmuir''s (R2=0. 8868). According to results of the present study، it was found that pistachio nut-shell has a high capacity to remove Reactive Red 198 dye from aqueous solutions and textile industry wastewater.