Title of article :
Equilibrium, Isotherm, Kinetic and Thermodynamic Studies of Removal of Crystal Violet by Adsorption onto a Natural Clay
Author/Authors :
Bentahar, S Laboratory of Bio-Organic Chemistry and Natural Products - Department of Chemistry - Faculty of Science - University Ibn Zohr - BP 8106, 80000 Agadir, Morocco , Lacherai, A Laboratory of Bio-Organic Chemistry and Natural Products - Department of Chemistry - Faculty of Science - University Ibn Zohr - BP 8106, 80000 Agadir, Morocco , Dbik, A Laboratory of Bio-Organic Chemistry and Natural Products - Department of Chemistry - Faculty of Science - University Ibn Zohr - BP 8106, 80000 Agadir, Morocco , El messaoudi, N Laboratory of Bio-Organic Chemistry and Natural Products - Department of Chemistry - Faculty of Science - University Ibn Zohr - BP 8106, 80000 Agadir, Morocco , El khomri, M Laboratory of Bio-Organic Chemistry and Natural Products - Department of Chemistry - Faculty of Science - University Ibn Zohr - BP 8106, 80000 Agadir, Morocco
Abstract :
This study reports the adsorption of crystal violet (CV) cationic dye on natural clay originated from Agadir region (south Morocco) through batch adsorption experiment, in order to develop a low-cost, natural, eco-friendly and alternative adsorbent for the removal of organic pollutants. Several analytical techniques (XRD, BET, TDA, TGA and FTIR) were used to characterize the studied material. The effect of different parameters were studied such as pH (3–10), adsorbent mass (0.02-0.3 g), contact time (20–120 min), initial dye concentration (100–900 mg/L), and temperature (25–65 °C) on the adsorption of CV dye. The results Showed That CV adsorption on the natural clay depends on pH, initial dye concentration and temperature. The adsorption equilibrium data were fitted in Langmuir, Freundlich and Timken adsorption isotherm models. The adsorption data obtained were well described by Langmuir isotherm model with correlation coefficients (R2 =0.99). Maximum adsorption capacity of clay was found to be 250 mg/g. Adsorption kinetics were well fitted by Pseudo-second order kinetic model (R2= 0.999). Thermodynamic study revealed that the adsorption of CV on clay is spontaneous physical sorption process, endothermic and favorable. Experimental results indicate that the clay studied is a promising adsorbent for the removal of cationic dye molecules from aqueous solutions.
Farsi abstract :
در اين مطالعه، به بررسي جذب سطحي رنگدانه كاتيوني كريستال ويوله (CV) روي خاك رس طبيعي نشات گرفته از منطقه آگادير (جنوب مراكش)، پرداخته است كه اين امر از طريق آزمايش جذب ناپيوسته به منظور تهيه جاذبي ارزان قيمت ، طبيعي و دوستدار محيط زيست براي حذف آلاينده هاي آلي صورت گرفت. چندين روش تحليلي (TGA TDA BET XRD و FTIR) براي تعيين خصوصيات مواد مورد مطالعه، استفاده شد و اثر پارامترهاي مختلف در جذب رنگدانه CV مانند پي اچ 7-3 ، جرم جاذب (0٫02 - 0٫3g)، زمان تماس (min 20 - 120 )، غلظت رنگ اوليه ( mg / L 900 - 100 ) و درجه حرارت ( 25 - 65°C ) مورد بررسي قرار گرفت. نتايج نشان داد كه جذب CV بر روي خاك رس طبيعي به pH، غلظت رنگدانه و درجه حرارت بستگي دارد. داده هاي تعادلي جذب سطحي، در مدل ايزوترم لانگموير، فروندليچ و تيمكن برازش شده و با توجه به مدل ايزوترم لانگموير با ضرايب همبستگي 099 به خوبي تشريح شدند. حداكثر ظرفيت جذب از خاك رس، مقدار mg / g 250 بدست آمد و سينتيك جذب به خوبي توسط مدل جنبشي شبه- درجه دوم برازش داده شد. مطالعه ترموديناميكي نشان داد كه جذب CV بر روي خاك رس يك فرآيند جذب فيزيكي خود بخودي ، گرماگير و مطلوب است. نتايج تجربي نشان مي دهد كه اين خاك رس، جاذب اميدبخشي براي حذف مولكولهاي رنگدانه كاتيوني از محلول هاي آبي است.
Keywords :
Adsorption , Clay , Dye , Kinetic , Isotherm models , Thermal Analysis
Journal title :
Astroparticle Physics
