ارزيابي عملكرد دانه بلوط به عنوان منعقد كننده و كمك منعقد كننده در تصفيه آب Evaluation of Oak Seed as Coagulant and Coagulant aid in Water Treatment

چكيده انگليسي :

Evaluation of Oak Seed as Coagulant and Coagulant Aid in Water Treatment Pooya Paydary Pooya paydary@yahoo com 4 12 2011 Department of Civil Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiAmir Taebi Harandi amirth@cc iut ac irAbstractTurbidity removal not only produces limpid water but also destroys pathogens by removing colloidal particlesand the microorganisms attached to them and prevents a large number of waterborne diseases In the water andwastewater treatment industry coagulation is a common process in removing turbidity in the form of suspendedand colloidal materials Many coagulants are widely used in conventional water treatment processes includinginorganic and polymeric coagulants In recent years because of problems associated with usage of thesecoagulants including cost and health related issues there has been considerable interest in the development ofusage of natural coagulants which can be produced or extracted from microorganisms animal or plant tissues The advantages of these coagulants over the synthetic ones include safety to human health biodegradability anda wider effective dose range for various colloidal suspensions In this study ability of Oak seed as a coagulantand coagulant aid was evaluated To achieve this goal tannic acid one of the main constituents of oak seed wasused In this study two kinds of tannic acid laboratory tannic acid and industrial tannic acid and two kinds ofturbid samples Zayanderood river water with natural turbidity and synthetic turbid water were used In order tooptimize the removal efficiency seven factors including pH coagulant dosage rapid mixing rate slow mixingrate slow mixing time sedimentation time and initial turbidity were investigated and experiments were carriedout in batch reactors and on four samples Lab Tannic acid Syn Turbidity Lab Tannic acid Natural Turbidity Ind Tannic acid Syn Turbidity and Ind Tannic acid Natural Turbidity Taguchi method was used in order todecrease the number of experiments expenses and time Using an L32 array optimum conditions for each of thesamples were determined Results showed that in optimum conditions laboratory tannic acid is capable ofreducing turbidity with 60 7 and 51 9 efficiency in synthetic and natural turbid samples while industrialtannic acid yielded 49 4 and 46 9 turbidity removal efficiency for synthetic and natural turbid samples ANOVA showed that all of the experimental factors were statistically significant in Ind Tannic acid Syn Turbidity and Ind Tannic acid Natural Turbidity samples and in Lab Tannic acid Syn Turbidity and Lab Tannic acid Natural Turbidity samples coagulant dosage was found to be the only statistically insignificantparameter ANOVA results revealed that the contribution of error term in the total results for all the samplesexcept Lab Tannic acid Natural Turbidity sample is less than 16 and for this sample is equal to 18 Interaction analysis were carried out to investigate the relative importance of different interactions betweeninvolved factors in this sample and it was concluded that the most important interaction in this sample happensbetween rapid mixing rate and slow mixing rate Considering the behavior of the coagulants and the IR testresults it was concluded that bridging and sweeping mechanisms are the most important mechanisms in turbidityremoval using tannic acid Overall this study showed that tannic acid is capable of decreasing turbidity and canbe used as a cheap alternative for high cost common coagulants in wastewater treatment Key WordsTurbidity Coagulation and flocculation Oak seed Taguchi Tannic acid

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ارزيابي عملكرد دانه بلوط به عنوان منعقد كننده و كمك منعقد كننده در تصفيه آب Evaluation of Oak Seed as Coagulant and Coagulant aid in Water Treatment

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