Tez özetleri Astronomi ve Uzay Bilimleri Anabilim Dalı 2

Investıgatıon Of Membrane Foulıng Mechanısms In The Anaerobıc Membrane Bioreactor (Anmbr): Applıcatıon Of Pharmaceutıcal Industry
In this study, treatability of etodolac chemical synthesis wastewater’s from the pharmaceutical industry was investigated in an AnMBR system and membran fouling mechanisms were researhed. The AnMBR reactor used in this study was operated with submerged membrane module (FM MP005 MF membrane, 66 cm² surface area) which was run at methanogenic phase. Reactor has a 4 L volume and was operated with pH: 7, temperature: 35^oC and continuous stirred and theoritical infinite sludge age (SRT=∞) for 557 days. COD was gradually increased to 2500 mg/L, 5000 mg/L, 7500 mg/L, 10000 mg/L, and 15000 mg/L. The COD removal efficiency up to 15000 mg/L COD loading period was approximately obtained between 85-90%. After feeding with 15000 mg/L COD, the removal efficiency consistently decreased to 60% and the lowest removal efficiency values were obtained throught all operation period. It was realized that the reduction of COD removal efficiency was caused by sulfide inhibition. Raw wastewater was ozonized and the reactor was fed with the ozonated raw wastewater (16 000 mg/L COD) for the last 167 days of operating period due to increased load values which has caused to sulfite inhibition in the AnMBR system. At the loading values of 2500, 5000, 7500, 10000 and 15000 mg/LCOD the related parameters were as follows: the flux rates of 2.1, 1.6, 1.1, 1.18 and 0.9 L L/m².h; the HRT of 12, 15.6, 22.9, 21.4 and 27.6 days. According to the analysis results of AnMBR operation period, the removal efficencies of sulfate, sulfite, etodolac and COD reached to 76%, 99%, 90% and 95%, respectively. At the beginning of operation period the TVS/TS rate was %20 and increased to 40% in short time. After feeding with ozonated raw wastewater this rate was balanced between %6-12. Ozonation had not special impact on the increase of the TVS. The experimental studies at different OLR values were investigated relationship between floc structure, the contents of EPS and SMP, surface properties, wastewater viscosity and membrane fouling. PCR and FISH analysis were performed to determine the microbial population.
Membrane fouling is the main focus of this research. Therefore, the membrane fouling mechanisms were intensively investigated by the empirical membrane pore blockage models, adsortion and adsorption-membrane pore clogging models which are calculated with ‘Sigma-Plot’ program through determination of iteration values to calculate the flux models that cause flux reduction. The membrane autopsy analysis were also conducted on the clean, dirty and stripped membrane surfaces. After 557 days of operation period, the clean, dirty and mud scraped membranes were analyzed by SEM–EDS, FT–IR, zeta potential, contact angle, confocal microscope imaging, and optikprofilometr measuremements of surface roughness. The mud deposited on membrane surface was analyzed by ICP–OES, TOC, EPS and SMP analysis. The autopsy process has showed that the cake layer deposited on the membrane was as thick as 600µm. The inorganic precipitation such as calcium and salt crystals was also observed on the surface of membrane. The roughness of dirty membranes was found the highest compared to clean and stripped membranes. The negative surface charge of the clean membrane has changed to positive value after the biological contamination.Consequently, the removal efficiencies of COD and etodolac in this study were reached to 90% and 84.1-90.7%, respectively when the resoasons of inhibition in AnMBR improved, though the increase of fouling and the flux reduction occured in membane.