Tez özetleri Astronomi ve Uzay Bilimleri Anabilim Dalı

Investıgatıon of Advanced Treatment Alternatıves for Wastewater

of Baker’s Yeast Industry Treated Bıologıcally
In this study, reuse of biologically treated baker’s yeast industry wastewater by using membrane and ozonation advanced treatment scheme was aimed. It was investigated the usage of recycled water for the purpose of agricultural irrigation. In this context, it was aimed to contribute to literature and industrial application. In the first section of this study, advanced treatment of baker’s yeast wastewater by membrane processes was studied. This section experiments comprised of membrane screening, determining of optimum filtration conditions, enchament of permeate quality for agricultural irrigation. In the membrane screening membrane performance (pollutant removal efficiencies) and membrane fouling (flux declines, contact angle measurements) were evaluated together for studied membranes (FM UP020, FM UP005, NF 270, NF 90 and Desal 5DL). The lowest total flux decline (35%) and flux decline caused by fouling (%5) was occurred for Desal 5DL. The highest removal efficiencies were obtained by NF 90 membrane whereas 90% total flux decline was occurred. Desal 5DL was decided as suitable membrane in membrane screening part. The experiments were conducted at different pH (3, 7 and 10), transmembrane pressure (12, 18 and 24 bar) and temperature (25 ⁰C, 35 ⁰C and 45 ⁰C) values for determining the effects of filtration conditions on the pollutant removal and membrane fouling. The optimum filtration conditions were determined as pH:7; transmembrane pressure: 12 bar and temperature: 25 ⁰C. Membrane fouling mechanisms at different filtration conditions were evaluated using contact angle, AFM (Atomic Force Microscopy) and FTIR (Fourier Transform Infrared Spektroscopy) measurements. Lower flux decline caused by membrane fouling was occured for NF 90 membrane rather than BW 30 membrane in the enchament of permeate quality part. In the second section of this study, advanced treatment of baker’s yeast wastewater by ozonation processes was studied. The effect of different pH (3, 7.5, 9 and 11) and temperature (25⁰C, 35⁰C and 45⁰C) values on the pollutant removal efficiencies and ozone consumption. Higher color removal efficiency (96–98%) was obtained whereas rather lower conductivity removal efficiency (10%) was obtained by ozonation at optimum conditions. Higher permeate quality was achieved with BW 30 membrane that used followed by the ozonation process.
In the third section of this study, it was evaluated the usage of water obtained by two step NF treatment and ozonation/reverse osmosis treatment as agricultural irrigation. As a result, B grade agricultural irrigation was obtained for both proposed treatment process. Also, II. grade agricultural irrigation was achieved as compared to agricultural irrigation chemical quality.