فهرس المقالات Freundlich isotherm

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  1 - کاربرد فناوری نانوزئولیت در حذف سولفات رودخانه گاماسیاب
  امین رضائی حسین بابازاده امیر خسروجردی مهدی سرائی تبریزی
  10.30495/jrnr.2023.72983.10288
  فعالیت های انسانی، وجود املاح در بستر رودخانه و رواناب ها و همچنین آلودگی های حمل شده توسط هوا منجر به آلوده شدن رودخانه‌ها به عنوان یکی از اصلی ترین منابع تامین آب می‌شود. در این پژوهش با انتخاب رودخانه گاماسیاب، نمونه گیری از 16 نقطه مورد نظر برای سه بازه زمانی أکثر

  فعالیت های انسانی، وجود املاح در بستر رودخانه و رواناب ها و همچنین آلودگی های حمل شده توسط هوا منجر به آلوده شدن رودخانه‌ها به عنوان یکی از اصلی ترین منابع تامین آب می‌شود. در این پژوهش با انتخاب رودخانه گاماسیاب، نمونه گیری از 16 نقطه مورد نظر برای سه بازه زمانی در آلوده ترین محل که دارای بیشترین میزان آلاینده نسبت به سایر ایستگاه ها را پس از آزمایش اسپکتوفتومتری از نمونه ها داشت، در فصل سال انجام شد. نمونه های جمع آوری شده پس از انتقال به آزمایشگاه مورد سنجش و تعیین میزان آلاینده هدف قرار گرفتند. سپس به منظور تصفیه با استفاده از نانوذره زئولیت طبیعی و اصلاح شده شبیه سازی شدند. در ادامه با استفاده از مدل Design Expert و فرض دو عامل pH و نسبت جاذب به آلاینده ، ضمن یافتن نقاط بهینه جذب، مقادیر جذب تئوری نیز یافت شدند. نتایج تحقیق نشان داد راندمان جذب برای نمونه اصلاح شده با 0/2 مولار نیتریک اسید و سولفوریک اسید برابر با 77 درصد برآورد شد. از بررسی اندرکنش سولفات با سه آلاینده شاخص دیگر شامل فسفات، نیترات و آهن که به وسیله شبیه سازی محلول و به منظور خنثی کردن اثر سایر مواد محلول صورت گرفت، مشخص گردید یون های فسفات و نیترات منجر به کاهش جذب یون سولفات توسط جاذب شده و یون آهن منجر به افزایش جذب سولفات توسط جاذب می‌شود. همچنین نتایج شبیه سازی مدل مورد نظر نشان داد نقطه بهینه جذب برای جاذب برابر با 9/6=pH و 17/01=D/C بوده و مقادیر مورد نظر منجر به جذب آلاینده به میزان 86/5 درصد می‌شود. در نهایت ایزوترم فروندلیچ برای این جاذب با ضریب تعیین 0/92 به عنوان ایزوترم برتر نسبت به ایزوترم لانگمویر با ضریب تعیین 0/79 انتخاب شد. تفاصيل المقالة
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  2 - Heavy Metals (Cr (VI), Cd (II) and Pb (II)) Ions Removal by Modified Jute: Characterization and Modeling
  M. Yari M. A. Mohsen F. Khojasteh O. Moradi
  Jute modified has been used for adsorption of Cr (VI), Cd (II) and Pb (II) ions over a range ofinitial metal ion concentration. Adsorption process is done in batch mode. Adsorption isotherms ofthe heavy metals on adsorbents prepared were determined and correlated with c أکثر

  Jute modified has been used for adsorption of Cr (VI), Cd (II) and Pb (II) ions over a range ofinitial metal ion concentration. Adsorption process is done in batch mode. Adsorption isotherms ofthe heavy metals on adsorbents prepared were determined and correlated with common isothermequations. It was found that the Freundlich isotherm is better than Langmuir for explaining thebehavior of adsorption. The effect of some parameters such as adsorbent quantity, pH value andtemperature were investigated. The enlargement of pH value until 5 and adsorbent quantityincrease the adsorption quantity. Whereas exceed of the temperature has the reverse effect. تفاصيل المقالة
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  3 - Adsorption of thallium (III) ion from aqueous solution using modified ZnO nanopowder
  H. Dashti Khavidaki H. Aghaie M. R. Shishehbore
  In this study, the adsorption of thallium (III) ion from aqueous solutions onto modified ZnOnanopowder as a fairly low cost adsorbent has been investigated in batch mode. It was found thatmodification of the adsorbent was essential for obtaining the significant adsorpti أکثر

  In this study, the adsorption of thallium (III) ion from aqueous solutions onto modified ZnOnanopowder as a fairly low cost adsorbent has been investigated in batch mode. It was found thatmodification of the adsorbent was essential for obtaining the significant adsorption percentage. Theadsorbent modified by sodium phosphate solution. The effect of experimental parameters such asinitial pH of solution, contact time, adsorbent dosage, thallium initial concentration and temperaturewas studied. The results showed that the adsorption percentage was dependent on this parametersspecially pH. The successful adsorption percentage of thallium (III) ion obtained at 25±1°C was 92.2-92.6%. The equilibrium data could be well described by the Freundlich isotherm but its fitting byLangmuir model was not so successful. Separation factor, RL, values showed that modified ZnOnanopowder were favorable for the sorption of thallium (III) ion. تفاصيل المقالة
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  4 - Isothermal and thermodynamic studies of the adsorption of safranine on MCM-41
  Ghazaleh Koutchakzadeh Zohreh Derikvand
  The uses of MCM-41 as adsorbent have been studied as an alternative substitution of activated carbon for theremoval dyes. This adsorbent was prepared at laboratory by authors. Adsorption of safranine on MCM-41was studied to examine adsorption thermodynamics. In this stu أکثر

  The uses of MCM-41 as adsorbent have been studied as an alternative substitution of activated carbon for theremoval dyes. This adsorbent was prepared at laboratory by authors. Adsorption of safranine on MCM-41was studied to examine adsorption thermodynamics. In this study was investigated the effect of proccesparameters like pH, initial dye concentration, temperature and adsorbent mass. MCM-41, as adsorbent, ischaracterized by high surface area and high pore volume to adsorbed dye very well. In this study, bothLangmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms. Langmuirmodel being has found to provide the best fit of experimental data. Results of thermodynamic evaluationindicated that adsorption reaction was spontaneous because Gibs energy was negative. This reaction wasexothermic with negative enthalpy and reducing entropy. تفاصيل المقالة
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  5 - Modified Sawdust as an Efficient Adsorbent for the Removal of Eosin Y Dye: Optimization, Isotherm, Regeneration of Adsorbent, and Real Sample Studies
  Leila Afrasiyabi Shahla Elhami Rostam Shabani
  10.22034/jchr.2023.1930392.1307
  In the current investigation, the utilization of sawdust was modified through chemical means employing diethylenetriamine. This modified form of sawdust served as an effective adsorbent for the purpose of adsorbing Eosin Y dye from aqueous samples. The chemical modifica أکثر

  In the current investigation, the utilization of sawdust was modified through chemical means employing diethylenetriamine. This modified form of sawdust served as an effective adsorbent for the purpose of adsorbing Eosin Y dye from aqueous samples. The chemical modification procedure was thoroughly examined, comparing the fourier transform of infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) before and after the modification. Various factors including solution pH (ranging from 2 to 6), adsorbent dosage (ranging from 0.2 to 2.0 g L-1), contact time (ranging from 5 to 35 min), agitation rate, and initial dye concentration (ranging from 20 to 1000 mg L-1) were investigated. Remarkably, the modified sawdust exhibited a notable uptake capacity at ambient temperature and successfully removed approximately 96% of the Eosin Y dye with a mere 1.2 g L-1 of adsorbent in just 5 minutes. Moreover, it was discovered that the adsorbent maintained its promising adsorption ability even after undergoing ten cycles of adsorption and desorption. The Freundlich isotherm model was employed to determine the adsorption parameters. This methodology was also implemented to eliminate dye from authentic samples of diverse water sources. تفاصيل المقالة
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  6 - Removal of Chromium (VI) from Wastewater by Palm Kernel Shell-based on a Green Method
  Maryam Razavi Mehr Mohammad Hossein Fekri Faezeh Omidali Noushin Eftekhari Behrouz Akbari-adergani
  10.22034/jchr.2019.664165
  The potential of palm kernel shell, as agricultural waste, to remove Cr (VI) from aqueous solution was evaluated. Effective parameters such as pH (2–8), temperature (20–80 °C), contact time (10-120 min), adsorbent concentration (0.1–1 g/L), and ini أکثر

  The potential of palm kernel shell, as agricultural waste, to remove Cr (VI) from aqueous solution was evaluated. Effective parameters such as pH (2–8), temperature (20–80 °C), contact time (10-120 min), adsorbent concentration (0.1–1 g/L), and initial Cr (VI) concentration (10-100 mg/L) were all studied to attain the maximum removal efficiency. Results show the adsorption capacity increases as pH value decreases and the optimum pH value is pH= 2.0. The other optimal conditions are temperature 40 °C, contact time 45 min, adsorbent concentration 0.5 g/L and initial Cr (VI) concentration 10 mg/L. The equilibrium data for chromate adsorption well fitted to Freundlich equation, with maximum adsorption capacity of 125 mg/g. This novel activated carbon derived from palm shell powder has been found to be effective for the removal of Cr (VI) and not noxious to the ecosystem. تفاصيل المقالة