Determination of optimum conditions of cheese whey treatment in an anaerobic treatment sludge reactor

VIDETERMINATION OF OPTİMUM CONDİTİONS OF CHEESE WHEYTREATMENT IN AN ANAEROBIC TREATMENT SLUDGE REACTOR(M.Sc. Thesis)Esra ÖZTÜRKGAZI UNIVERSITYINSTITUTE OF NATURAL SCIENCESFebruary 2007ABSTRACTIn this study, optimum conditions for the treatment of cheese whey in ananaerobic sludge reactor were determined by using a batch system. Twentyglass reactors each having 250 mL volume were used. Reactor temperature andpH can be controlled, and different design conditions can be providedsimultaneously. Gases produced as a result of the activities of microorganismsduring the anaerobic digestion were collected in graduated burettes. Reactionmixture consists of the cheese whey and inoculation microorganisms containingtreatment sludge that was taken from an anaerobic digester. In this study,effects of temperature (X1), pH (X2) and volumetric ratio of treatment sludge onanaerobic treatment were investigated. Experiments were designed by usingBox-Wilson experimental design method. Statistical analysis of experimentalresults were made by using ?Design Expert 7.03? package program. Afterevaluation of the experimental results, percent reduction of COD ( Chemicaloxygen demand) (Y1) had been expressed with Y1 = 37,13+ 2,80*X1 + 1,87*X3 +1,17*X1X2 + 1,88*X1X3-1,51*X2X3 -2,41*X12-3,49*X22-2,15*X32 modelequation as a function of given parameters above. R2 value had been estimatedas 0.9596 .The highest percent reduction of COD was found as 39.17 % at 37.80C, pHvalue of 7.19 and volumetric percent of treatment sludge of 14.20.VIIIt was determined that the most effective parameter on COD reduction percentis temperature and volumetric percentage of treatment sludge was found as thesecond effective parameter. Also it was found that, first order effect of anotherindependent parameter pH on COD reduction percent is negligible where as itsbinary interactions with other parameters was important.Science Code : 903.1.066Key Words : Anaerobic digestion, cheese whey, treatment sludge,statistical analysis,COD reductionPage Number : 113Adviser : Assoc. Prof. Dr. İrfan ARAsisst. Prof. S. Ferda MUTLU