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Keywords

Date stone
chemical activation
adsorption
Acidic and basic dyes

Abstract

This research includes a lab scale work to investigate the feasibility of treating waste water which polluted with dyes exhausted from textile factory by using adsorption process. Three type of activated carbon were prepared using locally available waste material (date stone). Chemical activation method  with (zinc chloride, potassium hydroxide, or phosphoric acid) was used  as activators  to  prepared carbon. Firstly, the materials were carbonized at 275 oC for 90 min and then the carbonized materials were treated with (4 molar) solution of acid, base or salt for 24 hour. Finally, these materials were activated at 600 oC for two hours in the presence of nitrogen gas flow. The resulted activated carbons were checked by its (BET) surface area analysis and surface morphology by SEM. The surface area values were (815, 950,600) m2/g for carbon produced from the activation of date  stone by phosphoric acid, potassium hydroxide or zinc chloride respectively. SEM characterizations show that activated carbons that prepared from potassium hydroxide have higher surface area and good adsorption characteristics than that prepared from activation with phosphoric acid or zinc chloride. The  adsorption process was studied using two types of dyes. The first one is acidic (methyl orange) and the other is basic (bismark brown). The adsorption isotherms and kinetics where investigated for both dyes at temperatures (30,40,50,60)oC for concentration  range  equal to (6-16)mg/l.  The  adsorption data of equilibrium were presented by using two common adsorption isotherm equations. The data was fitted fairly well with Langmuir isotherm for both dyes on all types of prepared activated carbons. The kinetic of adsorption was study by using two kinetic equations, pseudo first order and pseudo second order. The result showed the rapid increase in the rate of adsorption at the initial until equilibrium achieved. Pseudo second order model were represent the data very well with confidence level 0.99.
https://doi.org/10.30772/qjes.v13i1.622
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