Yazar "Kayaalp, Necati" seçeneğine göre listele
Listeleniyor 1 - 13 / 13
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Anoxic treatment of agricultural drainage water in a venturi-integrated membrane bioreactor(Multidisciplinary Digital Publishing Institute (MDPI), 2023) Kayaalp, NecatiDue to low sludge production and being a clean source without residuals, hydrogen-based autotrophic denitrification appears to be a promising choice for nitrate removal from agricultural drainage waters or water/wastewater with a similar composition. Although the incorporation of hydrogen-based autotrophic denitrification with membrane bioreactors (MBRs) enabled almost 100% utilization of hydrogen, the technology still needs to be improved to better utilize its advantages. This study investigated the anoxic treatment of both synthetic and real drainage waters using hydrogen gas in a recently developed membrane bioreactor configuration, a venturi-integrated submerged membrane bioreactor, for the first time. The study examined the effects of the inflow nitrate concentration, and the use of a venturi device on the removal efficiency, as well as the effects of the presence of headspace gas circulation and circulation rate on membrane fouling. The study found that using the headspace gas circulation through a venturi device did not significantly affect the treatment efficiency, and in both cases, a removal efficiency of over 90% was achieved. When the inlet NO− 3 –N concentration was increased from 50 mg/L to 100 mg/L, the maximum removal efficiency decreased from 98% to 92%. It was observed that the most significant effect of the headspace gas circulation was on the membrane fouling. When the headspace gas was not circulated, the average membrane chemical washing period was 5 days. However, with headspace gas circulation, the membrane washing period increased to an average of 12 days. The study found that the headspace gas circulation method significantly affected membrane fouling. When the upper phase was circulated with a peristaltic pump instead of a venturi device, the membrane washing period decreased to one day. The study calculated the maximum hydrogen utilization efficiency to be approximately 96%.Öğe A comparison of a blower and a Venturi aeration system in a submerged membrane bioreactor(Desalination Publ, 2017) Kayaalp, Necati; Ozturkmen, Gokmen; Gul, Ertugrul; Gunay, ElifA novel aeration method for submerged membrane bioreactors (MBR) was developed in this study. This method uses a Venturi injector to supply the air to the MBR. Short term experiments were performed to determine the technical applicability of integrating a venturi device into a submerged MBR. A flat-sheet, 0.1-mu m polyvinylidene fluoride membrane was used to operate the MBR. Real wastewater taken from Diyarbakir Municipal Wastewater Treatment Plant was used as feed. Membrane fouling was evaluated under three different fluxes (18, 32, and 50 L/m(2) . h) and 3 L/min aeration rate for both blower-and venturi-aerated MBR systems. Transmembrane pressure (TMP), chemical oxygen demand (COD), mixed liquor suspended solids, mixed liquor volatile suspended solids, pH, dissolved oxygen, and temperature were measured in the experimental setup. The COD removal rate was between 75-92% for blower system and 85-87% for venturi system. Effluent NH4-N concentration was between 0.0-14.7 mg/L for blower system and 0.0-0.7 for venturi system. While the effluent NO3-N was between 3.1-27.4 mg/L for blower system, it was 33.3-37.8 mg/L for venturi system. At 3 L/min aeration rate, the dissolved oxygen concentration in MBR was between 0.42-3.43 mg/L for blower-aerated system and between 6.43-7.07 mg/L for venturi-aerated system. TMP development at different fluxes in blower and venturi systems showed that integration of a venturi device with a submerged MBR improved filtration capacity significantly. The rate of TMP increase in blower-aerated system was higher than that of venturi-aerated system at the same aeration rate of 3 L/min for both systems. At the highest filtration flux tested (50 L/m(2) . h), venturi-aerated system operated three times longer than the blower system.Öğe Correlation of filtration resistance with microbial polymeric substances extracted from membranes in a submerged membrane bioreactor(Wiley-Blackwell, 2014) Kayaalp, Necati; Kınacı, Cumali; Dizge, Nadir; Hamidi, Nizamettin; 0000-0002-6136-5025; 0000-0003-1775-3466; 0000-0002-7805-9315; 0000-0003-0244-0264The current understanding of membrane fouling in submerged membrane bioreactors is still insufficient. Therefore, the role of microbial polymeric substances in membrane fouling mechanisms in a submerged membrane bioreactor was systematically investigated in this study. Microbial polymeric foulants accumulated on the membrane surface and in its pores. The foulants were then extracted in three steps, without deforming the membrane structure. Moreover, filtration resistances were determined by the resistance in series model. A strong functional relationship was observed between total polymeric substances accumulated in the membrane and their fouling resistances. The greatest accumulation of polymeric substances occurred in cake layers formed on the membrane surface. Correspondingly, the greatest fouling resistance resulted from the cake layer. The results indicated that more protein accumulated on the membrane surface than carbohydrates because the proteins were stickier. Regarding the analysis of microbial polymeric substances, it was observed that the filtration with a 0.45 mu m pore size filter did not capture all of the polymeric substances that took part in membrane fouling.Öğe Dicle havzasındaki akarsularda sediment taşınımının matematiksel modellerle belirlenmesi(2016) Kayaalp, Necati; Hamidi, NizamettinDicle Havzası, M.Ö. 4500 yılından bu yana kültür ve modernleşmede önemli bir rol oynamıştır. Güneydoğu Anadolu Projesi'nin ikinci önemli su kaynağı olan bu havzanın ülkemiz sınırlan içerisinde drenaj alanı 37.280 km2, yıllık ortalama akış miktarı 14.710 milyon m3 tür. Erozyon ve onun sonucu olan sediment taşınımı ve birikimi insanlar ve toplumlar üzerinde ekolojik ve ekonomik açıdan önemli etkileri olan bir olaydır. Bir yandan erozyonla verimli tanm alanları yok olurken, diğer yandan erozyon sonucu oluşan ve nehirlerin taşıdığı sedimentle de içme, sulama ve kullanma suyu temininde çeşitli güçlüklere ve barajları doldurarak ekonomik ömürlerinin kısalmasına neden olmaktadır. Havzalarda çeşitli istasyonlarda ölçülen sediment miktarları, iklim özelliklerine, yağış-akış ilişkilerini etkileyen havza özelliklerine, ayrıca sedimentin oluşmasında ve taşınmasında önemli rol oynayan akım özelliklerine bağlı olarak değişir. Bu amaçla havzaların ölçülen sediment veriminin, bu verim üzerinde etkili olan değişkenlerle bağıntıya getirilmesi ve böylece elde edilen eşitliklerden yararlanılarak matematik modellerinin belirlenmesi, ölçüm yapılamayan benzer nitelikteki havza akarsulanndaki sediment verimlerinin tahmin edilebilmesi olanağı vermektedir. Bu araştırma çalışması, Dicle Havzası akarsulannda farklı örnekleme istasyonlarında kullanılan veriler, Elektrik İşleri Etüt İdaresi ve Devlet Meteoroloji İşleri tarafından yönetilen sürekli ölçüm ve analiz işlerinden elde edilmiştir. Dicle Havzası sınırlan içinde bulunan Dicle Nehri, Botan Çayı ve Garzan Çayı'nda taşınan süspanse- sediment miktarlannın matematiksel modellerinin kurulması amaçlanmıştır. Matematiksel model olarak Yapay Sinir Ağlan (YSA) ve Regresyon Analizi (RA) yöntemleri kullanılarak, her akarsu için kurulan 14 modelden çeşitli istatistiklere göre en az hatayı veren model uygun model olarak seçilmiştir. Her iki modelde de yağış, sıcaklık ve akım parametreleri bağımsız değişken, süspanse- sediment parametresi ise bağımlı değişken olarak ele alınmıştır. Bu çalışmadan, her üç akarsuyun süspanse-sediment miktarlannın modellenmesinde YSA modellerinin RA modellerinden daha iyi sonuçlar verdiği görülmüştür. ANAHTAR KELİMELER: Dicle Nehri, Sediment Taşınımı, Erozyon, Matematik Model, Yapay Sinir Ağlan (YSA), Regresyon Analizi (RA).Öğe Estimating IDF curves under changing climate conditions for different climate regions(IWA Publishing, 2023) Gül, Burak; Kayaalp, NecatiAlthough climate models can highlight potential shifts in intensity–duration–frequency (IDF) curves, their limited geographical and temporal resolutions limit their direct use in predicting sub-daily heavy precipitation. To use global or regional model outputs to predict urban short-term precipitation, approaches that give the requisite level of spatial and temporal downscaling are required, and these processes remain one of the difficulties that have demanded intensive effort in recent years. Although no novel methods are given in this work, there are few studies in the literature that investigate the impact of climate change on the analysis and design of infrastructure-related engineering structures. Therefore, the purpose of this research is to determine the potential changes in IDF curves because of climate change. The equi-distance quantile matching method was used to turn future rainfall forecast data from global climate models (HadGEM2-ES, MPI-ESM-MR, and GFDL-ESM2M) corresponding to RCP4.5 and RCP8.5 scenarios into standard duration rainfall data, and new IDF curves were generated. These IDF curves corresponded very well with those generated from observed data (R2 ≈ 1). The HadGEM2-ES model predicts up to a 25% rise in rainfall intensity, whereas the other two models expect up to a 50% drop.Öğe Estimation of the amount of suspended sediment in the tigris river using artificial neural networks(Wiley, 2008) Hamidi, Nizamettin; Kayaalp, Necati; 0000-0003-0244-0264; 0000-0002-6136-5025The amount of sediment should be taken into consideration in the planning of water structures for efficient use of limited water resources. it is important to estimate the amount Of Sediment for the successful operation of these structures in their future performances. Such estimations can be achieved by Artificial Neural Network (ANNs) with low error percentages as seen in many other disciplines. These networks also enable the modeling of nonlinear relationships between the parameters affecting the event. The purpose of this research is to establish models for sediment amounts in the Tigris River at the Diyarbakir measurement station in Turkey. Rainfall, temperature and discharge are taken as independent variables in the models, whereas sediment is taken as the dependent variable. Fourteen different models are generated using ANNs and Regression Analysis (RA). The results are compared with each other and with the observed data. The relative error and determination coefficient are used as comparison criteria. It is concluded that due to their nonlinear modeling capability, ANNs give better results than RA.Öğe Membran biyoreaktörlerde venturi enjektörü kullanarak işletme maliyetinin azaltılmasının araştırılması(2015) Önen, Fevzi; Bağatur, Tamer; Kayaalp, Necati[Abstract Not Available]Öğe Modelling of hydrogenotrophic denitrification process in a venturi-integrated membrane bioreactor(Taylor and Francis Ltd., 2022) Gül, Ertuğrul; Kayaalp, NecatiThe aim of this study is to model a hydrogenotrophic denitrification process in a venturi-integrated submerged membrane bioreactor (MBR) system. The MBR was operated in batch mode using feed concentrations of 100 and 150 mg NO3-N/L. In contrast to most of the denitrification process models that represent the mixed culture with one composite biomass parameter, the biomass was subdivided into two main categories in this modelling study: mainly nitrate-reducing biomass and mainly nitrite-reducing biomass. The determination coefficients (r 2) in the range of 0.97–0.99 indicate that the model successfully simulates the concentrations of nitrate- and nitrite-nitrogen in the bioreactor. The maximum specific growth rate of nitrite-reducing biomass (0.06 h−1) was found to be higher than that of nitrate-reducing biomass (0.0002 h−1). Similarly, the growth yield coefficient of nitrite-reducing biomass was higher than that of nitrate-reducing biomass (0.44 vs. 0.31 g biomass/g substrate). The kinetic and stoichiometric coefficients obtained from this modelling study suggest that the limiting step determining the overall conversion rate of hydrogenotrophic denitrification process is the conversion of nitrite to nitrogen gas.Öğe Optimization of water distribution networks using hybrid BBO-IWO algorithm(Taylor and Francis Ltd., 2023) Batmaz, Veli; Kayaalp, NecatiDue to the increasing population and the pollution of existing water resources because of various factors, the need for water in the world is increasing. This requires building additional water distribution systems along with rehabilitation of existing systems. The cost of transmission and distribution constitutes more than half of the total cost of water supply systems. For this reason, by the optimum design of pipeline systems, the cost of water supply can be reduced. In this study, the optimization of pipe diameters in three networks, Two- Loop, Hanoi and GoYang, was carried out by a combination of two metaheuristic algorithms, namely Biogeography based optimization (BBO) and invasive weed optimization (IWO) under the same constraints. In addition, the Combined Gravity Network was successfully optimized with the current method for the first time in the literature.Öğe Sızıntı Suyu Arıtımı Yapan Membran Biyoreaktörlerde Membran Kirlenmesine Etki Eden Faktörler ve Tıkanma Kontrolü(2017) Kayaalp, Necati; Atay, Burcu; Koyuncu, İsmail; Özgün, Hale; Erşahin, Mustafa Evren; Dereli, Recep KaanKatı atıkların arazide depolanması yüksek kirlilikte sızıntı suyu oluşumuna neden olduğu için yüzeysel ve yeraltı su kaynakları için önemli bir tehdit oluşturmaktadır. Diğer biyolojik arıtma yöntemleriyle karşılaştırıldığında, membran biyoreaktörler (MBR) ile yüksek kalitede arıtılmış su elde edilebildiğinden, MBR'lerin sızıntı suyu arıtımında son yıllarda daha çok tercih edildiği görülmektedir. Bu çalışmanın amacı sızıntı suyu arıtımı yapan MBR'lerde tıkanma nedenlerinin ortaya konulması ve tıkanmayı azaltmak için en uygun metodun belirlenmesidir. Sızıntı suyu arıtımı yapan tam ölçekli iki MBR tesisi (MBR-1 ve MBR-2) kıyaslandığında; karbonhidrat bazlı çözünmüş mikrobiyal ürünler (ÇMÜk) değeri MBR-2 tesisinde MBR-1'e göre yaklaşık 5 kat daha fazladır. Her iki tesis için hücre dışı polimerik maddeler (HPM) miktarında ÇMÜ miktarı kadar fark olmamakla birlikte, MBR-2'de MBR-1'e göre HPM miktarı daha yüksektir. Bu durum MBR-2'de görülen tıkanma problemlerinde, ÇMÜ'nün başlıca rol oynadığını göstermektedir. Tıkanma kontrolü ile ilgili deneysel sonuçlar dikkate alındığında, membran tıkanmasını azaltacak en uygun yöntemin 50 mg/L konsantrasyonda toz aktif karbon (TAK) eklenmesi olduğu belirlenmiştir.Öğe Tarımsal Drenaj Sularının Geri Kazanımı(2018) Kayaalp, Necati; Üzen, NeşeTarımsal Drenaj Sularının Geri Kazanımı adlı bu projede, tarımsal faaliyetler sonucu olusan atıksuların karakterize edilmesi ve arıtılarak yeniden kullanılması ile ilgili çalısmalar yapılmıstır. Proje kapsamında Harran Ovası sulama sahası çalısma yeri olarak seçilmis ve seçilen noktalarda olusan drenaj sularının karakterizasyonu yapılmıstır. Buna ek olarak nitrat ve tuz içerigi nispeten yüksek olan çesitli noktalardan alınan drenaj sularının, laboratuvar ölçekli sistemler ile arıtımı gerçeklestirilmistir. Yapılan karakterizasyon çalısması sonucunda drenaj sularının karbon içeriginin sınırlı oldugu, bazı kanallarda drenaj suyunun tuz ve nitrat konsantrasyonlarının sulama suyu standartlarının üstünde oldugu gözlenmistir. Yapılan arıtma çalısmasında drenaj sularından nitrat gideriminin hidrojene dayalı ototrofik bir proses ile giris NO3-N konsantrasyonunun 50?100 mg/L olması durumunda %98 oranında giderim veriminin elde edilebilecegi görülmüstür. Drenaj sularının TDS degerlerinin 3000?5000 mg/L olması durumunda düsük enerjili ters ozmos membranları ile %93?98 tuz giderim veriminin elde edilebilecegi gözlenmistir.Öğe Testing of System Performance for Different Aerator Configuration Using Venturi(2018) Bagatur, Tamer; Kayaalp, Necati; Onen, FevziAbstract: A venturi tube or pipe part or device allows air bubbles to be inserted into flowing water from air inletholes and so increases dissolved oxygen (DO) levels in water. Therefore, the aim of this paper is to evaluatesystem design and experimental results related to configuration of venturi tube in air vacuum and aerationprocess. Different aerator modules constructed using venturi tubes connected in either single or double in parallel(with single or double outlet pipe line) were evaluated and compared for their air flowrate, vacuum capacity,oxygen transfer coefficients (OTC), standard oxygen transfer rate (SOTR), and standard oxygenation efficiency(SOE) determined by clean water tests. The experimental results indicated that the double parallel design(connected to a single outlet pipe line) generally performed better than the single and double parallel (connectedto a double outlet pipe line) design in terms of transferring oxygen into water.Öğe A venturi device reduces membrane fouling in a submerged membrane bioreactor(Iwa Publishing, 2016) Kayaalp, Necati; Ozturkmen, GokmenIn this study, for the first time, a venturi device was integrated into a submerged membrane bioreactor (MBR) to improve membrane surface cleaning and bioreactor oxygenation. The performances of a blower and the venturi device were compared in terms of membrane fouling and bioreactor oxygenation. Upon comparing membrane fouling, the performances were similar for a low operation flux (18 L/m(2).h); however, at a medium flux (32 L/m(2).h), the venturi system operated 3.4 times longer than the blower system, and the final transmembrane pressure was one-third that of the blower system. At the highest flux studied (50 L/m(2).h), the venturi system operated 5.4 times longer than the blower system. The most notable advantage of using a venturi device was that the dissolved oxygen (DO) concentration of the MBR was in the range of 7 to 8 mg/L at a 3 L/min aeration rate, while the DO concentration of the MBR was inadequate (a maximum of 0.29 mg/L) in the blower system. A clean water oxygenation test at a 3 L/min aeration rate indicated that the standard oxygen transfer rate for the venturi system was 9.5 times higher than that of the blower system.
