Person: MERTOĞLU, BÜLENT
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MERTOĞLU
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BÜLENT
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Publication Metadata only Investigation of nitrogen converters in membrane bioreactor(TAYLOR & FRANCIS INC, 2011) MERTOĞLU, BÜLENT; Ozdemir, Burcu; Mertoglu, Bulent; Yapsakli, Kozet; Aliyazicioglu, Cigdem; Saatci, Ahmet; Yenigun, OrhanIn this study, the activity and diversity of nitrogen converters, ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB), ammonia-oxidizing archaea (AOA) and Anammox bacteria in a pilot-scale membrane bioreactor (MBR) were investigated and monitored using amoA and 16S rDNA-based molecular tools. The pilot-scale MBR (100 m(3)/day) was located inside the full-scale Pasakoy Advanced Wastewater Treatment Plant (WWTP), and operated for approximately 5 months without sludge purge. During 148 days of operation, volatile suspended solids (VSS) concentration increased from 2,454 mg/L to 10,855 mg/L and the average organic carbon and ammonia nitrogen removal rates were 92% and 99%, respectively. Real-time PCR results indicated that the fraction of AOB increased from 2.94% to 4.05% when VSS concentration reached to 3,750 mg/L throughout 148 days of operation. At higher VSS concentrations, the fraction of AOB declined gradually to 1.15% while the fraction of Nitrospira population was varied between 8.23 and 13.01%. However, significant change or any positive and negative correlations between VSS concentration and Nitrospira population were not observed in this period. The phylogenetic analysis revealed that MBR harbored diverse AOB community which was related to the Nitrosomonas and Nitrosospira lineage. Candidatus Nitrospira defluvii was the only detected NOB in this study.Publication Metadata only Identification of nitrifiers and nitrification performance in drinking water biological activated carbon (BAC) filtration(ELSEVIER SCI LTD, 2010) MERTOĞLU, BÜLENT; Yapsakli, Kozet; Mertoglu, Bulent; Cecen, FerhanIn this study laboratory scale biological activated carbon (BAC) columns were operated with water taken from a surface water reservoir in Istanbul. The aim was to evaluate the efficiency of nitrification in columns packed with two different granular activated carbon grades (open superstructure/chemically activated and closed superstructure/steam activated carbon) and to examine the probable beneficial effect of pre-ozonation. The occurrence and diversity of ammonia-oxidizing bacteria were investigated using 16S rDNA and amoA gene based molecular techniques. Nearly complete removal of NH4+-N was achieved by nitrification in both carbon types. The nitrification efficiency did not change in columns fed with ozonated water. However, the type of feed (either raw or ozonated) played a more important role than the type of GAC with respect to the dominance of nitrifier species in BAC columns. In biofilters ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) were most closely related to Nitrosomonas spp. and Nitrospira spp. as determined by cloning and slot-blot analysis, respectively. The fraction of the AOB population in the biomass was high as detected by real-time PCR. The amoA/16S rDNA ratio varied from 28.7% to 2.1% along the depth of filters. In spite of similar removal efficiencies, BAC columns fed with ozonated water harbored different types of AOB than columns that were receiving raw water. (C) 2010 Elsevier Ltd. All rights reserved.Publication Metadata only Evaluation of Biological Activated Carbon (BAC) process in wastewater treatment secondary effluent for reclamation purposes(ELSEVIER SCIENCE BV, 2011) MERTOĞLU, BÜLENT; Kalkan, Cigdem; Yapsakli, Kozet; Mertoglu, Bulent; Tufan, Deniz; Saatci, AhmetThe effects of two different granular activated carbon (GAC) types (steam activated, PK1-3 and chemically activated, CAgran) on dissolved organic carbon (DOC) removal. nitrification and denitrification were evaluated in BAC columns for wastewater reclamation/reuse purposes. Continuous-flow laboratory-scale BAC columns were operated for 320 days using the secondary effluent water of Pasakoy Advanced Wastewater Treatment Plant. During the first 83 days of column operation, when adsorption was the dominant mechanism, the average DOC removal efficiency was 81% for PK1-3 and 64.5% for CAgran. Later on, the efficiencies dropped to 45.9% for PK 1-3 and 37.8% for CAgran. which shows the operational time period when breakthrough is reached and DOC removal is dominantly due to biodegradation. BAC columns were also capable of removing total nitrogen; removal efficiencies were observed to be 54.0% for the biofilter packed with PK1-3 and 51.5% for the one packed with CAgran. The results also showed that DOC and ammonia nitrogen concentrations immediately decrease due to dilution and biodegradation at the top of the BAC columns. This study establishes that a carefully operated BAC system, which was used for tertiary treatment of a secondary effluent, can remove organic carbon and total nitrogen to a significant extent. (C) 2010 Elsevier B.V. All rights reserved.Publication Metadata only Treatment of landfill leachate using UASB-MBR-SHARON-Anammox configuration(SPRINGER, 2013) MERTOĞLU, BÜLENT; Akgul, Deniz; Aktan, Cigdem Kalkan; Yapsakli, Kozet; Mertoglu, BulentLeachate treatment is a challenging issue due to its high pollutant loads. There are several studies on feasible treatment methods of leachate. In the scope of this study, high organic content of young leachate was eliminated using an upflow anaerobic sludge blanket (UASB) and a membrane bioreactor (MBR) in sequence and effluent of the system was given to single reactor for high activity ammonia removal over nitrite (SHARON) and anaerobic ammonia oxidation (Anammox) reactors to remove nitrogen content. All reactors were set up at lab scale in order to evaluate the usage of these processes in sequencing order for leachate treatment. COD and TKN removal efficiencies were over 90 % in the combined processes which were operated during the study. The biodegradable portion of organic matter was removed with an efficiency of 99 %. BOD5 concentration decreased to 50 mg/L by UASB and MBR in sequence even the influent BOD5 concentration was over 8,000 mg/L. Although high nitrogen concentrations were observed in raw leachate, successful removal of nitrogen was accomplished by consecutive operations of SHARON and Anammox reactors. The results of this study demonstrated that with an efficient pretreatment of leachate, the combination of SHARON-Anammox processes is an effective method for the treatment of high nitrogen content in leachate.Publication Metadata only Short- and long-term effects of copper on anammox under gradually increased copper concentrations(SPRINGER, 2021) MERTOĞLU, BÜLENT; Aktan, Cigdem Kalkan; Yapsakli, Kozet; Mertoglu, BulentThis study aims to determine both short- and long-term response of enriched anammox culture to Cu. Assessment of short-term inhibition is based both on total applied Cu concentration and potential bioavailable fractions like intracellular, surface-bound, soluble and free Cu ion. The half maximal inhibitory concentration (IC50) values for total applied, soluble, intracellular and cell-associated concentrations were determined as 4.57 mg/L, 1.97 mg/L, 0.71 mg/L, 1.11 mg/L, respectively. Correlation between the surface-bound fraction of Cu and inhibition response was weak, suggesting that Cu sorbed to biomass was not directly responsible for the effects on anammox activity. There was a disparity between the results of short- and long-term experiments in terms of inhibition threshold concentration (i.e. short-term IC50 = 4.57 mg/L vs long-term IC50 = 6.74 mg/L). Candidatus Kuenenia (59.8%) and Candidatus Brocadia (40.2%) were the two main anammox genera within the initial biomass sample. One of the most interesting finding of the study is the demonstration that a complete wash-out of C. Brocadia genus at an applied Cu concentration of 6.5 mg/L. This strongly indicates that C. Brocadia were not able to tolerate high copper concentrations and all nitrogen conversion was carried out by C. Kuenenia during the Cu exposure period.Publication Metadata only Anammox-zeolite system acting as buffer to achieve stable effluent nitrogen values(SPRINGER, 2017) MERTOĞLU, BÜLENT; Yapsakli, Kozet; Aktan, Cigdem Kalkan; Mertoglu, BulentFor a successful nitrogen removal, Anammox process needs to be established in line with a stable partial nitritation pretreatment unit since wastewater influent is mostly unsuitable for direct treatment by Anammox. Partial nitritation is, however, a critical bottleneck for the nitrogen removal since it is often difficult to maintain the right proportions of NO2-N and NH4-N during long periods of time for Anammox process. This study investigated the potential of Anammox-zeolite biofilter to buffer inequalities in nitrite and ammonium nitrogen in the influent feed. Anammox-zeolite biofilter combines the ion-exchange property of zeolite with the biological removal by Anammox process. Continuous-flow biofilter was operated for 570 days to test the response of Anammox-zeolite system for irregular ammonium and nitrite nitrogen entries. The reactor demonstrated stable and high nitrogen removal efficiencies (approximately 95 %) even when the influent NO2-N to NH4-N ratios were far from the stoichiometric ratio for Anammox reaction (i.e. NO2-N to NH4-N ranging from 0 to infinity). This is achieved by the sorption of surplus NH4-N by zeolite particles in case ammonium rich influent came in excess with respect to Anammox stoichiometry. Similarly, when ammonium-poor influent is fed to the reactor, ammonium desorption took place due to shifts in ion-exchange equilibrium and deficient amount were supplied by previously sorbed NH4-N. Here, zeolite acted as a preserving reservoir of ammonium where both sorption and desorption took place when needed and this caused the Anammox-zeolite system to act as a buffer system to generate a stable effluent.Publication Metadata only Zeolit dolgulu filtrelerde Anammox kültürünün yetiştirilmesi(2009-05-28) BAKIRCI, KOZET; YİĞİT HUNCE, SELDA; MERTOĞLU, BÜLENT; BAKIRCI K., YİĞİT HUNCE S., Yılmaz A. G., MERTOĞLU B.Publication Metadata only Inhibitory effects of free ammonia on Anammox bacteria(SPRINGER, 2012) MERTOĞLU, BÜLENT; Aktan, Cigdem Kalkan; Yapsakli, Kozet; Mertoglu, BulentAnammox bacteria can effectively treat high ammonia and nitrite concentrations under anoxic environments. However, the presence of high ammonia and nitrite concentrations may cause free ammonia and nitrous acid inhibition at high pH and temperature environments. In this study, the inhibitory effect of free ammonia on Anammox bacteria was investigated in a lab-scale upflow fixed-bed reactor with Kaldnes biofilm carriers. Results of continuous operation showed that inhibition was not observed in the Anammox reactor when the free ammonia concentration gradually increased up to 150 mg/L. However, Anammox activity suddenly dropped to 10 % when the free ammonia concentration reached to 190 mg/L. Nevertheless, high influent ammonia and nitrite concentrations up to 1,500 and 500 mg/L, respectively, did not noticeably inhibit the Anammox activity. Gradually decreasing Anammox activity was also supported by fluorescent in situ hybridization (FISH) analysis. FISH and 16S rRNA gene analysis results revealed that main Anammox organisms were phylogenetically related to Candidatus Kuenenia stuttgartiensis, Candidatus Jettenia asiatica and Candidatus Brocadia anammoxidans.Publication Metadata only Identification and quantitative evaluation of nitrogen-converting organisms in a full-scale leachate treatment plant(ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD, 2011) MERTOĞLU, BÜLENT; Yapsakli, Kozet; Aliyazicioglu, Cigdem; Mertoglu, BulentThe presence of ammonia nitrogen in landfill leachates poses a significant problem for treatment plant operators. The nitrification-denitrification process mostly carries out the nitrogen conversion in biological treatment systems. However, recent research shows that other processes by anaerobic ammonia-oxidizing bacteria (Anammox) and ammonia-oxidizing archaea (AOA) were also responsible for the removal of nitrogen in biological systems. In this study, the nitrogen-converting microorganisms in the Bursa Hamitler Leachate Treatment Plant were identified and monitored by using molecular tools. Fluorescent in situ hybridization (FISH) and slot-blot hybridization results showed that the Nitrosomonas and Nitrospira species were the dominant ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB), respectively. Quantitative real-time PCR results indicated that AOB, NOB, AOA and Anammox bacteria exist in the leachate treatment plant. However, the removal of ammonia can be ascribed mainly to nitrification because AOB (1.5%) and NOB (11.3%) were predominant among all nitrogen-converting bacteria. The results of the phylogenetic analysis based on amoA and 16S rDNA gene revealed that the uncultured bacterium clone 4-24, Kuenenia stuttgartiensis genome fragment KUST_E and the uncultured Crenarchaeota clone NJYPZT-C1 belong to AOB, Anammox and AOA populations, respectively, and were the dominant species in their cluster. (C) 2010 Elsevier Ltd. All rights reserved.