بهينه سازي جذب زيستي مالاشيت گرين از محلول هاي آبي توسط ريز جلبك هاي سبزsenedesmus quadircauda chlorella vulgaris

چكيده انگليسي :

Optimization of Malachite Green Biosorption From Aqueous Solutions by Green Microalgae Scenedesmus quadricauda and Chlorella vulgaris Masoud Kousha E mail masoudkousha76@gmail com Department of Natural Resources Isfahan University of Technology Isfahan Iran 84156 83111Degree M sc Language FarsiO Farhadian Assist Prof Supervisor omfarhad@cc iut ac irS Dorafshan Assist Prof Supervisor sdorafshan@cc iut ac irAbstractThe present study was carried out to optimize the various conditions for biosorption of malachite green MG ions onto Scenedesmus quadricauda and Chlorella vulgaris biomass by applying Response Surface Method RSM The effects of process parameters such as initial MG concentration 2 6 and 10 mg L initialsolution pH 3 4 5 and 6 algae amount 40 80 and 120 mg L and contact time 10 50 and 90 min on thedye biosorption were analyzed using three level Box Behnken design Biosorption of dye from aqueoussolution was optimized in a batch mode The analysis of variance ANOVA for removal efficiency of MGions for S quadricauda and C vulgaris was used in order to validity a model Then the second orderpolynomial analysis and quadratic model was employed to find out the relationship between removalefficiency of MG and four independent variables In the quadratic models the regression equation obtainedafter the ANOVA indicated the correlation coefficient R2 as 0 9918 and 0 9936 for MG removal of S quadricauda and C vulgaris respectively Values of insignificant lack of fit of 0 6744 and 0 7171 obtainedfor S quadricauda and C vulgaris respectively P values of both models for MG removal by algae were 0 0001 Probability F less than 0 05 indicated model are significant Also the minimum value of standarderror design 0 42 around the central point indicates that present model can be used to conduct the designspace Thus the high R2 value insignificant lack of fit p value significant models P value and minimumvalue of standard error design indicating its high adequacy and validity of models in predicting the MGremoval percentage by S quadricauda and C vulgaris Therefore these models were used for furtheranalysis The contour plots show the type of interaction between the tested variables and hence allow us toobtain the optimum conditions On the basis the MG removal efficiency onto these algae was increased witha decrease in initial MG concentration at 2 10 mg L and an increase in initial solution pH 3 to 6 biomassamount nearly 40 to 100 mg L and contact time of reaction at 10 90 min In the optimum experimentalconditions the results showed that maximum dye removal efficiency of C vulgaris biomass 91 2 is morethan S quadricauda biomass 72 0 for biosorption of MG ions from aqueous suspensions In thisconditions various kinetic models of pseudo first order pseudo second order and intra particle diffusionwere examined and pseudo second order could much better explain the sorption kinetics of dye than othermodels R2 0 99 The FT IR spectroscopy method was used to obtain information on the nature of possibleinteractions between the functional groups of algal biomass and MG ions These observations indicated thatseveral functional groups especially carboxyl hydroxyl and amine groups on the surface of the S quadricauda and C vulgaris biomass are responsible for binding of MG ions in the biosorption process Furthermore different removal efficiency of MG onto S quadricauda and C vulgaris biomass can beattributed to different interaction between dye molecule and algal biomass These findings revealed that thesealgae are suitable biomaterial for MG removal from wastewaters Keywords Biosorption Scenedesmus quadricauda Chlorella vulgaris Response surfacemethodology Malachite green

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بهينه سازي جذب زيستي مالاشيت گرين از محلول هاي آبي توسط ريز جلبك هاي سبزsenedesmus quadircauda chlorella vulgaris

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