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Review Citation - Scopus: 30Reverse Electrodialysis for Salinity Gradient Power Generation: Challenges and Future Perspectives(Amirkabir University of Technology - Membrane Processes Research Laboratory, 2018) Güler,E.; Nijmeijer,K.Salinity 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 - Scopus: 22Seawater 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) Kaya,C.; Jarma,Y.A.; Muhidin,A.M.; Güler,E.; Kabay,N.; Arda,M.; Yüksel,M.In 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.Article Modeling Surface Water Quality and Nutrient Correlation With Sediment Oxygen Demand at Dam Water Reservoirs(Technoscience Publications, 2022) Abdulqader,N.N.; Işgör,B.S.; Genç,A.N.; Güler,E.; Seymenoǧlu,V.C.The 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.
