2011 YÜksek lisans tez özetleri

Application Of Experimental Design And Reuse Of Dairy Industry Wastewater By Membrane Technology

In this study, reuse of biologically treated dairy industry wastewater by using two-steps membrane process based on the nanofiltration and reverse osmosis advanced treatment scheme was aimed. The effect of filtration conditions on membrane removal efficiency and flux decline was investigated. Membrane fouling was also evaluated with contact angle, AFM and ESEM measurements.

In the first step of treatment scheme, the suitable nanofiltration membrane type and the filtration conditions (pH, temperature and transmembrane pressure) were determined by using Taguchi experimental design. L₁₆ orthogonal array which has four factors with four levels was selected. In addition, pollutant removal efficiencies of membranes and fouling mechanisms (flux declines) were evaluated in the first step of the treatment scheme. ANOVA method was applied for statistical analysis of the experimental results performed by using Taguchi experimental design method. As a result of ANOVA analysis, pH value of wastewater was found to be the most important factor on the flux decline caused by membrane fouling. Also, membrane, temperature and pH factors were found to be most important for SAK₂₅₄ removal while membrane and pH factors were found to be most important for conductivity and ammonia nitrogen removal. In addition, membrane factor was found to be important on the total hardness, chloride and sulfate removal. The membrane type and optimum filtration conditions were determined as Desal 5DL, pH=6; T=20⁰C; ΔP=12 bar, respectively for the first step of treatment by considering flux decline caused by fouling. Confirmation experiment was performed with combination of the optimum levels. It was determined whether the observed flux decline results (total flux decline, flux decline caused by fouling) obtained from confirmation experiment are in good agreement with predicted results or not within the calculated confidence intervals. At the second step of the treatment, the composite permeate obtained from the first step was treated by using a reverse osmosis membrane under 20 and 40 bars transmembrane pressures. The permeate quality obtained from reverse osmosis membrane (T=20⁰C; ΔP = 20 bar) was found to be better than process water used in the factory that supplied wastewater.

As a result, it was shown that process water could be obtained from biologically treated dairy industry wastewater by using two-steps membrane process based on the nanofiltration and reverse osmosis.

Bozkurt Ümit

Danışman : Yrd. Doç. Dr. Gülsüm Yılmaz

Anabilim Dalı : Çevre Mühendisliği

Mezuniyet Yılı : 2011

Tez Savunma Jürisi : Y. Doç. Dr. Gülsüm YILMAZ

Prof. Dr. Nilgün BALKAYA

Prof. Dr. Süleyman TANYOLAÇ

Prof. Dr. Nazlı ARDA

Doç. Dr. Bülent MERTOĞLU