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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Journal of Particle Science & Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Adsorption,Isotherm,Malachite Green,Modified perlite
- چکیده:
- چکیده انگلیسی: Adsorption of malachite green (MG) from an aqueous solution onto unexpanded perlite (UP), expanded perlite (EP) and NaOH-modified unexpanded perlite (NaOH-UP) powders has been investigated. The effects of contact time, pH, initial dye concentration, adsorbent dosage and temperature have been evaluated. The adsorbents were characterized by Brunauer-Emmett-Teller (BET) analysis, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). The obtained results proved that the three examined powders can be used successfully for removal of MG from aqueous solutions as low cost mineral adsorbents. The maximum adsorption capacities of UP, EP and NaOH-UP were 23.81 mg/g, 29.41 mg/g and 39.68 mg/g, respectively. Kinetic studies show that the kinetics of the MG adsorption onto the adsorbents followed the second order model. The MG equilibrium adsorption data were best described by the Langmuir isotherm model for all adsorbents.
- انتشار مقاله: 26-01-1396
- نویسندگان: Elahe Rostami,Reza Norouzbeigi,Ahmad Rahbar-Kelishami
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Particle Science & Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Adsorption,Kinetics,Taguchi Method,Crystal violet (CV+),Surfactant-modified dolomite
- چکیده:
- چکیده انگلیسی: This paper presents the adsorption of crystal violet (CV+) from aqueous solution on surfactant-modified dolomite. Liquid phase batch operations were carried out to observe the effect of various experimental parameters such as initial dye concentration, adsorbent dosage, pH and NaCl concentration. The optimum conditions for these parameters were calculated by Taguchi method. Equilibrium isotherm data were analyzed according to Langmuir, Freundlich and Temkin equations. The experimental data fitted well to Freundlich adsorption model. The maximum adsorption capacities by Langmuir analysis were determined to be 49.261mg/g at 22℃ that indicates suitable performance by of this adsorbent. The pPseudo-first-order and, pseudo-second-order kinetics and the intraparticle diffusion models were also evaluated for the adsorption of CV+ onto surfactant-modified dolomite. The positive value of free energy change confirmed the nature of physisorption of dye onto adsorbent.
- انتشار مقاله: 27-10-1395
- نویسندگان: Maryam Arabpour,Ahmad Rahbar-Kelishami,Reza Norouzbeigi
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Adsorption,Congo red,Bentonite,Langmuir,Thermally and chemically modification
- چکیده:
- چکیده انگلیسی: Raw bentonite (RB), a known low-cost versatile clay was used as an adsorbent. RB was treated thermally and chemically to increase its adsorption capacity. For thermal treatment (TTB), the bentonite was heated at 400 °C for 60 min, and for the chemical modification, its surface was treated by cetyltrimethylammonium bromide (CTAB) to prepare organo-modified bentonite (CTAB-B). The removal of Congo red dye (CR) from aqueous solution was investigated in the batch mode. The prepared adsorbents were characterized by SEM, BET, and FTIR analyses. The effects of various experimental parameters such as contact time, pH, adsorbent dosage, dye concentration and temperature were investigated. The obtained results were in good agreement with the Langmuir isotherm model, and the maximum adsorption capacity of RB, TTB and CTAB-B was 43.1, 55.86 and 116.28 mg/g, respectively. The adsorption kinetic was better described by the pseudo-second order kinetic model. The results showed that thermally or chemically modified bentonite could be proposed as a low-cost adsorbent for the removal of CR from water.
- انتشار مقاله: 01-10-1395
- نویسندگان: Elahe Rostami,Reza Norouzbeigi,Ahmad Rahbar
- مشاهده