حذف فلزات سنگين سرب، كادميوم و كروم با استفاده از زيست توده اصلاح شده و تثبيت شده در سديم آلژينات

چكيده انگليسي :

Removal of Lead Cadmium and Chromium from AqueousSolutions using Surface Modified and Alginate Entrapped Biomass Seyed Amir Alavi a alavi@ce iut ac ir August 18 2013 Department of Chemical Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor H Zilouei hzilouei@cc iut ac ir A Asadinezhad asadinezhad@cc iut ac irAbstractThere are heavy metals in wastewater of many industries such as the mining petrochemical oil refining paper pharmaceutical industry paint and plastic products industries Entering these metals into water resources cause toadd these metals to the food chain This action was done through the absorption of these metals bymicroorganisms and causes a lot of problems for humans To remove heavy metals there are various physical chemical and biological methods From these methods researchers pay attention to the biosorption processBecause of this method with using of a series less valuable materials are able to remove many heavy metals Biosorption is the physical and chemical absorption of heavy metals by living and non living microorganisms bacteria fungi algae and other organic object such as rice bran fruit skins leaves and skin of trees etc Atthis thesis the waste of Goldar and two brown algae Nizamuddin zanardini and marginutum were used forremoval of heavy metals such as lead cadmium and chromium The algal species Nizamuddin zanardini andmarginutum were acquired from Oman Sea coast of Chabahar and Otostegia persica known as goldar is anendemic plant that can be found in its natural habitat in Kerman province in Iran The standard stock solutions of20 mg L of Pb II Cd II and Cr VI were prepared by dissolving appropriate amount of Pb NO3 2 Cd SO4 8H2O K2 Cr2O7 in distillated water The alga was washed extensively with distilled water to removedust and other particles The clean biomass was sundried for 24 h and then in the oven at 50 C for 24 hAbsorbents were used initially as raw form and then modified with 4 phenyl 3 thiosemicarbazide and finally withsodium alginate polymer for removal three metals For these absorbents three models Langmuir Freundlich andTemkin were evaluated and the result shows a good conformity between the experimental data and Langmuirisotherm Langmuir isotherm shows a homogenous absorption on the homogenous surface and theoretical qm forabsorbent are acceptable with the experimental qm To investigate the kinetics of the process the pseudo secondorder model and intra particle diffusion was used Presenting this model intra particle diffusion was done forinvestigating of multistage absorption This absorption is as 2 3 stages In this model diagrams of sorptioncapacity inclusive sorption on the surface of biosorbent linear with high slopes penetrate the pores averagelinear slope and penetration in the biosorbent structure linear with very little slope were considered Ho spseudo second order model conform for most raw and modified absorbents The most important effectiveparameters into absorption process such as pH initial concentration and the amount of biomass was investigatedin this project The pH of the solutions was adjusted to a favorite value using 0 1 M NaOH and 0 1 M HCl Theresult shows that optimum pH for maximum removal of aqueous solution are 5 to 6 for cadmium and lead 3 to 4for chromium Another important effect observed in this project was increased absorption capacity with initialconcentration and the increase of absorption percentage with increase of biomass concentration Keywords waste Goldar Zanardini Marginutum Heavy metals Isotherms Kinetics

علوي، امير

حذف فلزات سنگين سرب، كادميوم و كروم با استفاده از زيست توده اصلاح شده و تثبيت شده در سديم آلژينات

ضايعات گلدر , زانارديني , مارجيناتوم , ايزوتروم , سينتيك