مقايسه دو روش پيش تصفيه انعقاد شيميايي و انعقاد الكتريكي و تركيب با سامانه غشايي اولترافيلتراسيون در تصفيه پساب كارخانه توليد خميرمايه نانوايي

چكيده انگليسي :

72 Comparison of Chemical Coagulation and Electrocoagulation and Combined them by Ultrafiltration and Nanofiltration for Treatment of the Baker s Yeast Wastewater Hossein Nouri Alavijeh h nouri2013@gmail com Date of Submission July 2015 Department of Chemical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Persian Supervisors Dr Morteza Sadeghi m sadeghi@cc iut ac ir Advisor Prof Ahmad Moheb ahmad@cc iut ac irAbstractIn this study at first effective performance of electrocoagulation method using electrodes made of aluminum Al and coagulation flocculation method using two types of coagulants lime and Polyaluminumchloride PACl in treatment of baker s yeast wastewater were studied In the electrocoagulation process effect of fourfactors including pH current density process time and magnetic stirrer mixing speed on removal efficiencyof COD and turbidity were evaluated The maximum removal efficiency of COD and turbidity in EC underoptimum operating conditions i e pH 5 current density of 120 A m2 operating time of 20 minutes andmixing speed of 200 rpm were 77 64 and 97 49 respectively Also in coagulation flocculation methodeffect of three factors including concentration of coagulant pH and fast mixing speed for lime and PAClinvestigated The maximum removal efficiency of COD and turbidity using lime as coagulant under optimumoperating conditions including concentration of 2000 milligrams per liter pH 8 and fast mixing speed of 150rpm were 68 09 and 89 39 respectively and for PACl as coagulant in optimal conditions i e concentration of 500 milligrams per liter pH 8 and fast mixing speed of 200 rpm were 71 05 and 90 62 respectively In addition of removal efficiencies of pollutions the operating cost of these two methods intheir optimal conditions according to two units of dollars per every cubic meter of wastewater $ m3 anddollar per kilogram of COD removal from wastewater $ kg COD removed evaluated and inelectrocoagulation were 0 574 and 0 217 respectively for coagulation by PACl 0 305 and 0 141 respectivelyand using lime as coagulant were 0 064 and 0 031 respectively Then the treated wastewater with twoelectrocoagulation and coagulation flocculation pretreatment processes used as feed of membrane systemsultrafiltration and nanofiltration Two types of Hollow fiber membrane polypropylene PP andpolyvinylidene fluoride PVDF in the same operating conditions ambient temperature and pressure of 6 bar used for ultrafiltration process and a spiral wound polyamide membrane at ambient temperature and pressureof 7 bar used in nanofiltration system The maximum removal efficiencies of COD and turbidity usingcoagulation flocculation as pretreatment in hybrid system of CC PVDF NF were 97 96 and 99 8 respectively and with treated wastewater of electrocoagulation pretreatment process in EC PP NF hybridsystem were 98 99 and 99 9 respectively Also for combination of two methods electrocoagulation andcoagulation flocculation the removal efficiencies of COD and turbidity were 88 88 and 99 25 for EC CCand 87 17 and 92 68 for CC EC respectively Finally with combination of EC CC system withultrafiltration and nanofiltration systems maximum COD removal efficiency of 99 67 for EC CC PVDF NF hybrid system achieved Keywords Coagulation flocculation Electrocoagulation Ultrafiltration Nanofiltration Baker s yeastwastewater hybrid methodes of wastewater treatment COD removal efficiency Turbidity removal efficiency

نوري علويجه، حسين

مقايسه دو روش پيش تصفيه انعقاد شيميايي و انعقاد الكتريكي و تركيب با سامانه غشايي اولترافيلتراسيون در تصفيه پساب كارخانه توليد خميرمايه نانوايي

روش هاي تركيبي تصفيه پساب , بازدهي حذف COD , بازدهي حذف كدورت