ارزيابي كارايي نشاسته به عنوان منعقد كننده همراه بنتونيت به عنوان كمك منعقد كننده در تصفيه آب

چكيده انگليسي :

Evaluation of Starch as Coagulants with Bentonit as a Coagulants aid in Water Treatment Vahid Ehsanpour V ehsanpour@cv iut ac ir 4 19 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 Mineral coagulants are frequently used forcoagulation Because of harmful metals including Aluminum and impurities as polluted monomers and heavymetals in this kind of coagulats the use of natural organic matter has been recently taken into consideration Inthis study ability of Starch as Coagulants with Bentonit as a Coagulants aid was evaluated In this study twokinds of starch laboratory starch and industrial starch and two kinds of turbid samples Zayanderood riverwater with natural turbidity and synthetic turbid water were used In order to optimize the removal efficiency four factors including pH coagulant dosage coagulant aid dosage and initial turbidity were investigated andexperiments were carried out in batch reactors Ful factorial method was used Results showed that in optimumconditions laboratory starch is capable of reducing turbidity with 84 in synthetic turbid samples ANOVAshowed that all of the experimental factors were statistically significant in Ind ANOVA results revealed that thecontribution of error term in the total results for all the samples is less than 13 Interaction analysis werecarried out to investigate the relative importance of different interactions between involved factors in thissample and it was concluded that the most important interaction in this sample happens between pH and initialturbidity Considering the behavior of the coagulants results it was concluded that bridging and sweepingmechanisms are the most important mechanisms in turbidity removal using starch and bentonit The jar test indifferent temperature showed that the turbidity omission output will be different by starch and bentonit which isdependent of raw water temperature Also the experiments showed that sedimentation and flocculationprocesses in coagulation by starch and bentonit will be completed in longer time than the frequent coagulation Overall this study showed that starch and bentonit is capable of decreasing turbidity and can be used as a cheapalternative for high cost common coagulants in wastewater treatment Key WordsTurbidity Coagulation and flocculation Starch Bentonit Full factorial

احسان پور، وحيد

ارزيابي كارايي نشاسته به عنوان منعقد كننده همراه بنتونيت به عنوان كمك منعقد كننده در تصفيه آب

كدورت , انعقاد و لخته سازي , فاكتوريل كامل