تصفيه پساب كارخانه توليد خمير مايه با سامانه تركيبي انعقاد سازي- اولترافيلتراسيون

چكيده انگليسي :

103 Baker s Yeast Wastewater Treatment by Combined Coagulation Ultrafiltration Process Mohammadreza Rajaeeyeh Reezax@yahoo com Date of Submission Jul 6 2013 Department of Chemical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language PersianSupervisor Morteza Sadeghi m sadeghi@cc iut ac irAbstractThe high load of organic materials such as sugars carbohydrates and fermented products is one of the maincharacteristics of the wastewaters of food industries These organic compounds exist in food industry swastewater causes some significant pollution in the environment The baker s yeast is a valuable substance inbread production process This substance increases alimental value palatability and volume of the bread Molass by product of sugar manufacturing is mainly used as a main raw material in the yeast production Molass contains 45 50 sugars 15 20 nonsugar organic substances 10 15 ash minerals and about20 water The sugars existed in the molasses are a source of carbon and energy in the yeast fermentationprocess However a major part of the nonsugar substances in the molasses are not assimilable by the yeastand then released unchanged to the wastewater The most part of the waste in the yeast production processare contains these compounds In addition waste water contains other substances like the added chemicalsduring fermentation e g antifoams propionic acids brine etc yeast metabolites and residual yeast cells Since these ef uents have high BOD and COD they need to be treated before discharging In this researchcoagulation flocculation process and membrane separation as a new approach was used to baker s yeastwastewater treatment The coagulation has been done in two ways befor membrane and during membranefiltration inline coagulation The first objective of this study was to investigate and enhancement of theefficiency of pre coagulation process on waste water treatment This target followed by changing the type ofcoagulant Alum Poly Aluminium Chloride PAC and lime and optimization of operating condition duringcoagulation Membrane separation was performed by poly propylene PP and poly vinylidene flouride PVDF The effects of trans membrane pressure cross flow velocity temperature and type of membranewere studied on permeate flux turbidity and COD removal in membrane process The obtained results showthat the flux of permeate increase and the turbidity and COD removal efficiency decrease by trans membranepressure cross flow velocity and temperature It also observed that coagulation and settling before UF hasbetter result than Inline coagulation It maybe due to that flocks need more time to enlarge In combinedprocess coagulation filtration of wastewater poly aluminum chloride has higher efficiency thanaluminuim sulphate and lime The combination of coagulation also has examined and was found to be quitee ective The combination of PAC and lime has had most efficiency and economic advantages incomparison to other combinations of coagulants At the optimum conditions in coagulation step the removalof turbidity and COD were 81 and 68 respectively At the best conditions in filtration step for PVDFmembrane the permeate flux turbidity and COD removal were 59 l m2h 99 and 74 5 respectively Forthis wastewater using PP membrane in filtration step at best conditions leads to permeate flux turbidity andCOD removal of 81 l m2h 97 and 65 respectively The highest turbidity and COD removal efficiency onthe coagulation and membrane filtration processes were obtained as 99 and 91 respectively Keywords Baker s yeast wastewater treatment Ultrafiltration membrane Chemical pretreatment hollow fiber membrane permeate flux turbidity removal COD removal

رجائيه، محمدرضا

تصفيه پساب كارخانه توليد خمير مايه با سامانه تركيبي انعقاد سازي- اولترافيلتراسيون

پيش تصفيه شيميايي , ميزان جريان تراوش يافته , ميزان حذف كدورت , ميزان حذف COD