Iron removal from aqueous solution by alumina nanoparticles coated with polyaniline

Background and Aims: In view of water crisis, effective prevention of water resources contamination is increasingly important. The presence of heavy metals in drinking water at concentrations greater than acceptable limits may result in various adverse health effects. The present study was conducted to evaluate the feasibility of alumina nanoparticles coated with polyaniline for iron removal from aqueous solutions.Materials and Methods: The direct synthesis method was used to cover the polyaniline film on alumina nanoparticles. Batch adsorption studies were performed as a function of contact time, temperature, adsorbent mass and pH. The adsorption isotherms at iron concentrations ranging from 10 to 150 mg/L as well as the reaction kinetics were also investigated.Results: The maximum efficiency of iron removal was found at pH 3, 24 ºC and 120 min contact time. The maximum sorption capacity of coated nano-alumina for Fe(II) removal was also found to be 45.66 mg g-1 at 0.1g of adsorbent mass.Conclusion: Results from this study demonstrated the potential utility of alumina nanoparticles coated with polyaniline showing 83% adsorption ability for iron removal from aqueous solutions.Key words: Alumina nanoparticles, Polyaniline, Adsorption, Iron ion

Production of Rosuvastatin Calcium Nanoparticles Using Gas Antisolvent Technique: Experimental and Optimization

The activity of pharmaceutical substances crucially depends on the bioavailability of the substances. The bioavailability of drugs in body and their rate of dissolution in the biological fluids are increased if the particle size is decreased. In the present paper, the Gas Anti-Solvent (GAS) method was used to lower the size of rosuvastatin particles. The effects of temperature (313–338 K), pressure (105–180 bar) and initial solute concentration (20–60 mg/ml) were evaluated by Response Surface Methodology (RSM). The optimum initial solute concentration, temperature and pressure were found to be 20 mg/ml, 313 K and 180 bar, respectively which resulted in the minimum particle size. Furthermore, the particles were characterized by Differential Scanning Calorimetry (DSC), Dynamic Light Scattering (DLS), Fourier Transform Infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and X-Ray Diffraction (XRD). The analyses showed that the rosuvastatin particles (60.3 nm) precipitated by GAS process become significantly smaller than the initial particles (45.8 µm)

پوشش نانوذرات آلومينا با پلي آنيلين جهت حذف يون آهن از محلول آبی

Background and Aims: In view of water crisis, effective prevention of water resources contamination is increasingly important. The presence of heavy metals in drinking water at concentrations greater than acceptable limits may result in various adverse health effects. The present study was conducted to evaluate the feasibility of alumina nanoparticles coated with polyaniline for iron removal from aqueous solutions.Materials and Methods: The direct synthesis method was used to cover the polyaniline film on alumina nanoparticles. Batch adsorption studies were performed as a function of contact time, temperature, adsorbent mass and pH. The adsorption isotherms at iron concentrations ranging from 10 to 150 mg/L as well as the reaction kinetics were also investigated.Results: The maximum efficiency of iron removal was found at pH 3, 24 ºC and 120 min contact time. The maximum sorption capacity of coated nano-alumina for Fe(II) removal was also found to be 45.66 mg g-1 at 0.1g of adsorbent mass.Conclusion: Results from this study demonstrated the potential utility of alumina nanoparticles coated with polyaniline showing 83% adsorption ability for iron removal from aqueous solutions.زمينه و هدف: با توجه به بحران آب، جلوگيری از آلوده شدن منابع آب بسيار اهميت دارد. يکي از عوامل آلوده کننده آب، فلزات سنگين است که مقادير بيش از حد آن باعث ايجاد بيماری‌های مختلف مي‌شود. اين مقاله جذب يون آهن از محلول آبي توسط نانوذرات آلومينای پوشش داده شده با پلی‌آنيلين را شرح مي‌دهد. مواد و روش‌ها: از روش سنتز مستقيم جهت پوشش فيلم پلي‌آنيلين روي نانوذرات آلومينا استفاده شد. براي تعيين فاکتورهاي موثر در جذب از سيستم راکتور ناپيوسته استفاده گرديد. اثر پارامترهاي مختلف مانند زمان، دما، مقدار جاذب و pH در جذب مورد بررسي قرار گرفت. همچنين ايزوترم‌های جذب در محدوده غلظت mg/L 150-10 يون آهن و معادلات سينتيکی جذب مورد مطالعه قرار گرفت.  يافته‌ها: بالاترين کارايی در حذف يون آهن در pH برابر 3، مدت زمان 120 دقيقه، جرم جاذب 1/0 گرم و دماي 24 درجه سانتيگراد بدست آمد و ماکزيمم ظرفيت جاذب برای يون آهن 66/45 ميلي‌گرم به ازاي هر گرم جاذب محاسبه شد.   نتيجه گيري: اين مطالعه نشان داد که نانوذرات آلومينای پوشش داده شده با پلی‌آنيلين با توانايی جذب 83 درصد از محلولppm 50 يون آهن، جاذب موثری برای حذف يون آهن از محلول‌های آبی است. &nbsp

Experimental solubility of aripiprazole in supercritical carbon dioxide and modeling

Abstract The solubility of compounds in supercritical carbon dioxide (SC- $${\mathrm{CO}}_{2}$$ CO 2 ) has found crucial significance in the fabrication of micro/nano-scaled drugs. In this research, the solubility of Aripiprazole was measured in SC- $${\mathrm{CO}}_{2}$$ CO 2 at various temperatures (308–338 K) and pressures (12–30 MPa). Moreover, the experimental solubility results were correlated with several semi-empirical models (Chrastil, Bartle et al., Kumar & Johnston, Menden-Santiago & Teja, Sodeifian et al., and Jouyban et al.) as well as the modified Wilson model. The molar fraction of the drug in SC- $${\mathrm{CO}}_{2}$$ CO 2 varied in the range of $$1.830\times {10}^{-6}$$ 1.830 × 10 - 6 to $$1.036\times {10}^{-5}$$ 1.036 × 10 - 5 . The solubility highly depended on the operating pressure and temperature. The Chrastil (0.994), Jouyban et al. (0.993) and Sodeifian et al. (0.992) models showed the highest consistency with the obtained values. Furthermore, self-consistency tests were performed on the solubility of Aripiprazole in SC- $${\mathrm{CO}}_{2}$$ CO 2 . The approximate total enthalpy ( $${\mathrm{\Delta H}}_{\mathrm{total}}$$ Δ H total ), vaporization enthalpy ( $${\mathrm{\Delta H}}_{\mathrm{vap}}$$ Δ H vap ), and solubility enthalpy ( $${\mathrm{\Delta H}}_{\mathrm{sol}}$$ Δ H sol ) were also calculated