عنوان :
مطالعه تعادلي و سينتيكي جذب سرب به وسيله پاليگورسكويت و سيپوليت در حضور امينو اسيدهاي سيستئين و هسيتيدين
مقطع تحصيلي :
كارشناسي ارشد
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي
صفحه شمار :
سيزده،96ص.: مصور،جدول،نمودار
يادداشت :
ص.ع.به فارسي و انگليسي
استاد راهنما :
مهران شيرواني
استاد مشاور :
فرشيد نوربخش
توصيفگر ها :
كاني هاي سيليكاته رشته اي , هم دماي جذب , كمپلكس سطحي سه گانه
تاريخ نمايه سازي :
29/3/92
استاد داور :
حسين شريعتمداري، جهانگير عابدي
چكيده فارسي :
به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي
چكيده انگليسي :
Equilibrium and kinetic studies on lead sorption by palygorskite and sepiolite in the presence of histidine and cysteine amino acids Zahra sherkat sherkatzahra@yahoo com January 2013 Department of Soil Science Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Assist Prof M Shirvani shirvani@cc iut ac ir Abstract Fate of heavy metals entered the soils is primarily controlled by interfacial reactions of the metals occurred on soil mineral surfaces Soil is a complex environment containing various minerals and organic substances each of which can react differently with heavy metal ions Therefore it is a common approach to examine the interactions of metals with individual soil constituents in model systems for better understanding the role of every soil component in mobility and fate of metals in the environment Free amino acids FAA are among the soluble low molecular weight organic compounds Amino acids can be obtained from a variety of sources such as wet and dry deposition root exudates dead roots and microbial and animal secretions These organic compounds affect the mobility and sorption of heavy metals in soil The e ect of cysteine and histidine on the sorption of lead by palygorskite and sepiolite was investigated in a laboratory experiment Sorption data were obtained at 0 01 M CaCl2 and 0 5 2 mmol L 1 for lead in the presence of 1 mmol L 1 cysteine and histidine and described using Freundlich Langmuir Koble Corrigan and Temkin models The Freundlich and Koble Corrigan models provided good fits for all sorption sets Sorption of Pb by sepiolite and palygorskite was decreased in the presence of cysteine probably because of the formation of soluble complexes of Pb cysteine in the solution The complexes are stable and neutral charged Histidine effect was different for the two minerals Sorption of Pb by palygorskite increased but that by sepiolite decreased in the presence of histidine In the sepiolite histidine system very stable soluble ML2H complex is the predominant form of Pb in solution Formation of these complexes between lead and histidine may reduce the amount of lead absorbed by the sepiolite In the palygorskite histidine system Pb mostly presents as ML2H2 2 and ML2H3 3 complexes which have a great desire to electrostatically sorbed by palygorskite There is also a possibility of ternary surface complexes formation in this system As a result Pb sorption by palygorskite was increased in the presence of histidine Sorption kinetics of Pb on both minerals was best tted to the power function equation both in the absence and presence of the cysteine and histidine Rate of Pb sorption on sepiolite mainly decreased in the presence of cysteine and histidine But in case of palygorskite Pb sorption rate was decreased in the presence of cystein and increased in the presence of the histidine confirming the results of equilibrium studies Keywords sorption amino acids fibrous clay minerals isotherm ternary surface complexes
استاد راهنما :
مهران شيرواني
استاد مشاور :
فرشيد نوربخش
استاد داور :
حسين شريعتمداري، جهانگير عابدي
