بررسي فرآيند جذب و واجذب يون كروم ﴿VI﴾ در سيستم پيوسته ي بستر ثابت حاوي نانو ذرات مغناطيسي اكسيدآهن

چكيده انگليسي :

84 Investigation of Chromium VI adsorption desorption process in fixed bed continuous system include Fe3O4 nanoparticles Mina Jadidi m jadidi@ce iut ac ir Date of Submission August 17 2015 Department of Chemical Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor Nasrin Etesami n etesami@cc iut ac irAdvisor Mohsen Nasr Esfahany m nasr@cc iut ac irAbstractHeavy metals contamination of water resources have turned to be one of the most significant environmentalchallenges in the recent years One of the most important and efficient methods in heavy metals removal isAdsorption process By the deployment of nanotechnology in various aspects including water andwastewater treatment nanoparticles were considered as one of the most effective adsorbents in heavy metaladsorption process Iron Oxide nanoparticles with special features such as large specific surface area easyaccess to resources and synthesis in nanoscale surface modification ability and special magnetic properties have been extremely considered In this research adsorption of chromium VI was investigated by magneticIron Oxide nanoparticles in a continuous system A cylindrical tube with internal diameter of 4 6cm theheight of 30 cm and a stainless steel bed into in was used as the adsorption column Nanoparticles wereembedded on a stainless steel bed by using a magnetic field Chromium solution was flowed through thecolumn in order to chromium removal Effective parameters on adsorption efficiency were investigated As aresult it was attained that by increasing the amount of nanoparticles in bed decreasing in the rate and ionsconcentration of feed flow adsorption efficiency of Chromium increases Maximum adsorption of Chromiumwas 15 67 mg of Chromium per 1 gram of adsorbent in condition of 1 2 gr of nanoparticles 7 ppmChromium concentration and 20 mL min flow rate One of the most substantial features of Adsorptionprocess is the possibility to recover and reuse the adsorbent In order to investigate desorption of theChromium from nanoparticles surface and to determine the optimal condition adsorption and desorptionprocesses were carried out in a batch system In the batch system adsorption efficiency of Chromium by ironoxide nanoparticles were 55 03 Sodium hydroxide NaOH 0 5 M was selected as the regenerativematerial In order to evaluate the ability of the nanoparticles to adsorb the chromium in consecutiveprocesses adsorption desorption of chromium were repeated up to 4 cycles Adsorption efficiency ofChromium enhanced from 55 in the first cycle to 90 in next cycles Zeta potential and FTIR analysis ofthe nanoparticles before and after processes were used for interpretation of this phenomenon and revealing ofadsorption mechanism After determining the proper regenerative material desorption process was carriedout in the continuous system By running adsorption desorption cycles up to 5 times in the continuoussystem it was clarified that the total adsorption efficiency of the column reduces Studying the results ofcontinuous adsorption desorption cycles reveals that if duration of the adsorption processes in cycles reduces total adsorption efficiency of the process per each cycle will increase Keywords adsorption Chromium magnetic nanoparticles Iron Oxide nanoparticles continuousadsorption process desorption process

جديدي، مينا

بررسي فرآيند جذب و واجذب يون كروم ﴿VI﴾ در سيستم پيوسته ي بستر ثابت حاوي نانو ذرات مغناطيسي اكسيدآهن

فرآيند جذب سطحي , فلز سنگين كروم , فرآيند جذب پيوسته