Browsing by Author "Güler,E."
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Book Part Citation Count: 0Application of Nanofiltration for Reclamation and Reuse of Wastewater and Spent Geothermal Fluid(CRC Press, 2023) Güler, Enver; Cihanoğlu,A.; Güler,E.; Tomaszewska,B.; Kasztelewicz,A.; Baba,A.; Kabay,N.; Chemical EngineeringAfter the extraction of energy from the geothermal fluid, the consumed geothermal water can be considered as a potential water resource for agricultural and industrial purposes. The used geothermal water can also be used as a source of drinking water, which could reduce the pressure on the current clean water resources. On the other hand, geothermal fluids brought to the surface need to be treated in the most economical way before discharge into the surface environment or aquifer. Several processes have shown promising results for the treatment of geothermal water. Membrane processes such as nanofiltration (NF) and reverse osmosis (RO) can be considered as a technology for obtaining good quality irrigation water from geothermal water. This chapter summarizes the application of NF for the recovery and reuse of wastewater and spent geothermal water. © 2024 selection and editorial matter, Abdul Wahab Mohammad, Teow Yeit Haan and Nidal Hidal; individual chapters, the contributors.Book Part Citation Count: 0Current status of ion exchange membranes for electrodialysis/reverse electrodialysis and membrane capacitive deionization/capacitive mixing(Elsevier, 2022) Güler, Enver; Güler,E.; Smolinska-Kempisty,K.; Bryjak,M.; Chemical EngineeringThe world is facing several critical problems, which were integrated by the United Nation into the 17 Sustainable Development Goals (SDGs). Adopted by all the U.N. member states, the SDGs provide goals for attaining a common welfare by 2030. Among these goals, access to clean water and green energy are the most important challenges. The use of ion exchange membranes for the production of safe water and harvesting renewable energy seem to meet these challenges. This chapter will present the history and perspectives of the use of ion exchange membranes for these struggles. © 2022 Elsevier Inc. All rights reserved.Book Part Citation Count: 0Green energy generation using membrane technologies based on salinity gradient(Elsevier, 2023) Güler, Enver; Cihanoğlu,A.; Altıok,E.; Kaya,T.Z.; Eti,M.; Kabay,N.; Chemical EngineeringElectrical energy can be extracted from salinity gradients, often represented by two aqueous solutions with different salinities. This becomes very interesting when sustainable and practical electromembrane processes can be applied to convert the salinity gradient power into electric power. Reverse electrodialysis (RED), in this context, has gained much interest in the last few years. In addition to many operational and design parameters affecting the process output, ion exchange membranes (IEMs) represent core elements in RED. In this chapter, it is aimed to introduce and discuss the current trend of IEMs as well as vital operational parameters and fouling affecting the RED performance. © 2023 Elsevier Inc. All rights reserved.Book Part Citation Count: 0Ion exchange membranes in electrodialysis process for wastewater treatment(Elsevier, 2023) Güler, Enver; Cihanoğlu,A.; Güler,E.; Kabay,N.; Chemical EngineeringWater is the most important natural resource on earth. Survival without water is impossible and industries cannot operate without water as well. Availability of safe and reliable source of water is therefore essential. Different practical solutions are needed for sustainable preservation of water resources as freshwater resources are limited in terms of technical and economical aspects. Membrane technologies can be applied to water and wastewater treatment for removal of various unwanted substances from water. Recently, the utilization of membrane technologies in the water purification sector has grown exponentially. Compared to conventional reclamation methods, membrane technologies are much more efficient for removal of various contaminants and they are able to overcome more stringent water regulations. Membrane separation processes employed for water treatment include reverse osmosis, nanofiltration, ultrafiltration, microfiltration, and electrodialysis (ED). In this chapter, we reviewed the basic principles of electromembrane processes, such as ED, electrodeionization, electrodialysis reversal, and bipolar membrane ED based on ion exchange membranes (IEMs) along with few examples of the use of these processes in water and wastewater treatment. In addition, fouling of IEMs is also discussed. © 2024 Elsevier Inc. All rights reserved.Article Citation Count: 0Modeling Surface Water Quality and Nutrient Correlation with Sediment Oxygen Demand at Dam Water Reservoirs(Technoscience Publications, 2022) Genç, Aslı Numanoğlu; Işgör,B.S.; Güler, Enver; Güler,E.; Seymenoǧlu,V.C.; Department of Civil Engineering; Chemical EngineeringThe work presented here is a model approach based on WASP8 (Water analysis simulation program) a water quality model simulated to represent contaminants at the surface and bottom sediments of Kurtboǧazi dam reservoir in Ankara city. However, our water quality output variables: are temperature, nitrate, total phosphorus, total Kjeldahl nitrogen, dissolved oxygen, Chlorophyll a, and ammonia. To ensure the model represents the actual case at the reservoir, the results from the simulation model were calibrated using actual data from the Kurtboǧazi dam site, the calibration utilizes statistical techniques. The first method was the goodness-of-fit, R2 between model variables and field data, and the results were in the range of 0.86 to 1.0 indicating excellent linear association. The second technique was the RE, the values of which obtained were less than 1, elaborating acceptable results. The dam reservoir Kurtboǧazi had been affected by the negative impact arising from dissolved oxygen depletion in the hypolimnetic layer during stratification periods and that had been well documented. However, the processes of oxygen consumption at the sediment-water interface are still difficult to grasp conceptually and mainly linked to sediment oxygen depletion and the phenomena of sediment oxygen demand SOD. The novelty of this research work is the development of a quality model to predict the reactions of state variables that are occurring at the water body and how they interact with each other and their influence on the overall quality status of the Kurtboǧazi reservoir, and the crucial factors influencing the depletion of oxygen at the water column; secondly, the effect of anoxic condition on the benthic flux and the impact of anoxia condition on the ratio of nitrogen to phosphorus ratio at the reservoir. It was evident from the results of calibration that the model successfully simulated the correlation of the parameters influencing the anoxic condition, and benthic flux and ratio shift from nitrogen-limited during the summer to phosphorus-limited at the beginning of winter. © 2022 Technoscience Publications. All rights reserved.Article Citation Count: 4New generation radiation-grafted PVDF-g-VBC based dual-fiber electrospun anion exchange membranes(Elsevier Ltd, 2024) Güler, Enver; Rajabalizadeh Mojarrad,N.; Alkan Gürsel,S.; Güler,E.; Yarar Kaplan,B.; Chemical EngineeringAnion Exchange Membranes (AEM) have the potential to solve the cost issues of fuel cell technologies due to their basic environment that can allow the use of cheaper components. However, there is still a need to develop an ideal inexpensive, mechanically robust AEM with high ionic conductivity and ion exchange capacity (IEC). In this work, we present various dual-fiber electrospun membranes based on a novel radiation-grafted copolymer. First, the synthesis route of radiation-induced grafting of vinyl benzyl chloride (VBC) onto poly (vinylidene fluoride) (PVDF) to prepare PVDF-g-VBC was optimized. Then, PVDF-g-VBC powders were used to fabricate dual-fiber electrospun mats with inert PVDF and commercial Fumion-FAA-3 ionomer. Dual-fiber electrospun mats were hot-pressed and then quaternized with trimethylamine. Finally, mechanical properties, ion exchange capacity, ionic conductivity, and morphology of these prepared dual-fiber electrospun membranes were investigated. The dual-fiber membrane prepared with PVDF-g-VBC (88% of the total weight of the membrane) and PVDF: Fumion-FAA-3 (1:2) mix (12 wt%) realized ionic conductivity of 4.67 mS/cm at 25 °C, high ion exchange capacity of 1.35 mmol/g with Young's Modulus of 761 MPa. The membrane based on the combination of radiation grafting and dual-fiber electrospinning was prepared for the first time in literature and offers the prospect of tuning and fine-control of mechanical and physicochemical properties of AEMs. © 2023 Hydrogen Energy Publications LLCReview Citation Count: 28Reverse electrodialysis for salinity gradient power generation: Challenges and future perspectives(Amirkabir University of Technology - Membrane Processes Research Laboratory, 2018) Güler, Enver; Nijmeijer,K.; Chemical EngineeringSalinity gradient energy, which is also known as Blue energy, is a renewable energy form that can be extracted from the mixing of two solutions with different salinities. About 80% of the current global electricity demand could potentially be covered by this energy source. Among several energy extraction technologies, reverse electrodialysis (RED), using anion and cation exchange membranes for ionic transport that is converted into an electrical current at the electrodes, is most promising. This study provides a brief overview of recent advances in RED technology. Furthermore, it discusses future research directions and prospects to expand the true potential of this technology for power generation. Major emphasis should be on the development of task-specific membranes and stacks, the control of fouling and the design of new applications and hybrid processes. © 2018 MPRL. All rights reserved.Article Citation Count: 19Seawater desalination by using nanofiltration (NF) and brackish water reverse osmosis (BWRO) membranes in sequential mode of operation(Amirkabir University of Technology - Membrane Processes Research Laboratory, 2020) Yüksel, Melis; Jarma,Y.A.; Güler, Enver; Güler,E.; Kabay,N.; Arda,M.; Yüksel,M.; Law; Chemical EngineeringIn this study, the applicability of nanofiltration (NF) membranes as a pretreatment prior to reverse osmosis (RO) in seawater desalination was investigated. The membranes used were NF270 and NF90 as the NF membranes, while the brackish water (BW) RO membrane BW30 was used as the RO membrane. In desalination tests, permeates of the NF membranes were collected and used as the feed to the BW30 membrane. The calculated permeate fluxes were 6.7 L/h.m2, 11.3 L/h.m2, 24.3 L/h.m2, and 36.6 L/h.m2 for single BW30-35 bar, NF270-30 bar + BW30-35 bar, NF90-30 bar + BW30-25 bar and NF90-30 BW30-35 bar, respectively. The calculated water recovery and rejected salt values were 51.6%, 41.4%, 24.8%, 15.4% and 98.2%, 98.2%, 96.0%, 91.0% for NF90-30 bar + BW30-35 bar, NF90-30 bar + BW30-25 bar, NF270-30 bar + BW30-35 bar and single BW30-35 bar, respectively. The qualities of the product waters of integrated systems (NF+BWRO) and the single BWRO system were also investigated. Boron rejection was fairly well with average boron rejections of 59.3% and 60.2% by NF90-30 bar + BW30-25 bar and NF90-30 bar + BW30-35 bar combinations, respectively while single BW30-35 bar gave an average rejection of 49.6%. The results obtained showed that the quality of product water obtained using single BWRO did not comply with the irrigation standards, while the integrated systems provided total compliance to irrigation standards with the exception of boron. © 2020 MPRL. All rights reserved.