در هنگام جستجو کلمه در قسمت عنوان میتوانید کلمات مورد جستجو را با کاراکتر (-) جدا کنید.
کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Nickel,Isotherm,Mesoporous MCM-41,Nano-adsorbent
- چکیده:
- چکیده انگلیسی: In this study, a synthetic and modified PPAP-MPTMS-MCM-41 nano-adsorbent was used to remove nickel (II) during a batch process. Studying the parameters that were effective on adsorption revealed that the PPAP-MPTMS-MCM-41 adsorbent was the most effective in the adsorption of nickel (II) from a standard solution (Conc. = 5 mg/L, volume = 100 mL) under the following conditions: pH=8, contact time = 20 min, 6 wt.% of poly para-aminophenol (PPAP) ligand, adsorbent mass = 0.3 g, 1 molar hydrochloric acid (to remove nickel from the adsorbent), and NaCl salt with a concentration of less than 100 g/L. The results showed that the Langmuir isotherm had a higher linear and non-linear fitting with the experimental data. Investigating the kinetic models and mass transfer of this adsorption process showed that the experimental data were in good agreement with the pseudo-second-order kinetic model and the intra-particle mass transfer model. According to thermodynamic studies, this adsorption process is endothermic; its Gibbs free energy value is positive such that with an increase in temperature, it goes to lower values, and thus the process progresses spontaneously.
- انتشار مقاله: 02-02-1399
- نویسندگان: Behrouz Raei,Afsaneh Barekat,Habibollah Shariyatinia
- مشاهده
- جایگاه : پژوهشی
- مجله: Advances in Environmental Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Zeolite,Adsorption,Copper,Hydrogel,Sodium alginate
- چکیده:
- چکیده انگلیسی: The study presented in this article investigated the removal of copper ions from aqueous solutions by a synthetic hydrogel-forming adsorbent polymer based on sodium alginate (SA) and hydroxy apatite (HA) nanoparticles. The effect of adding Zeolite on the adsorption performance of this hydrogel was also investigated, and the optimum amount of Zeolite was determined by changing its quantity. The FTIR spectrum determined the structure of the synthesized adsorbent; non-continuous adsorption tests were performed to study the kinetics and thermodynamics of adsorption and also the recovery of the adsorbent. The degree of adsorption of the synthesized nanocomposite was compared with that of Zeolite, and the results showed that the maximum adsorption capacities of Zeolite and the nanocomposite for Cu ions were 29.7 and 75.8 mg/g, respectively. The kinetic studies indicated that the process of adsorption of Cu ions on both absorbents followed a pseudo second order kinetic equation. It took the Zeolite and the hydrogel 90 and 120 minutes, respectively, to reach equilibrium. The thermodynamic studies showed that Cu absorption by both adsorbents matched the Langmuir isotherm very well (R2=0.99). Since adsorbent recovery and its lifespan are of significant importance in absorption processes, recovery was carried out by hydrochloric acid (2% by weight). The repulsion coefficient of the recovered adsorbent and its efficiency in five recovery cycles were measured. The results of the tests indicated that the repulsion coefficient of Cu was 70-82.75 percent and the adsorption efficiency of Cu after 5 recovery cycles was 75 percent of the initial adsorbent.
- انتشار مقاله: 14-05-1396
- نویسندگان: Afsaneh Barekat,Masoomeh Mirzaei
- مشاهده