Environmental Engineering / Çevre Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/4321
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Article Citation - WoS: 13Citation - Scopus: 14Boron Removal From Geothermal Brine Using Hybrid Reverse Osmosis/Microbial Desalination Cell System(Elsevier, 2023) Jarma, Yakubu A.; Kabay, Nalan; Baba, Alper; Ökten, Hatice Eser; Gören, Ayşegül YağmurAgriculture sector leads worldwide as the most water consuming sector with water demand. Since natural water resources cannot keep up with the demand, a shift from conventional water resources to unconventional ones is needed. While geothermal water was gaining importance for its energy content, small-scale (<10 L/s) energy plants were not required to reinject their spent geothermal brine. As geothermal resources align with agricultural areas in Western Anatolia, discharge of untreated brine might have severe adverse effects on crop yields and soil quality. In this study, we investigated use of spent geothermal brine for irrigation after treatment with Reverse Osmosis/Microbial Desalination Cell (RO/MDC) hybrid process. Treatment efficiencies for B, COD, As, Li, Fe, Cr concentrations and energy production values were determined. Treated water was initially evaluated for irrigation considering three quality categories (I, II, and III) comprised of parameters such as electrical conductivity (EC), total dissolved solids (TDS), and sodium adsorption ratio (SAR), along with sodium, chloride and boron concentrations. Additionally, magnesium adsorption ratio (MAR) and permeability index (PI) were used to evaluate for irrigation suitability. Although B concentrations in MDC-treated permeate (3.29 mg/L) and concentrate (2.99 mg/L) streams were not low enough to meet Quality I criterion (<0.7 mg/L), they can be still utilized in irrigation of moderate-to-high tolerant plants. Furthermore, PI and MAR parameters pointed to suitability for irrigational use. © 2022Article Citation - WoS: 10Citation - Scopus: 12Novel Hybrid Adsorption-Electrodialysis (aded) System for Removal of Boron From Geothermal Brine(American Chemical Society, 2022) Altınbaş, Bekir Fırat; Orak, Ceren; Ökten, Hatice Eser; Yüksel, AslıA novel hybrid adsorption-electrodialysis (AdED) system to remove environmentally harmful boron from geothermal brine was designed and effective operating parameters such as pH, voltage, and flow rate were studied. A cellulose-based adsorbent was synthesized from glycidyl methacrylate (GMA) grafted cellulose and modified with a boron selective n-methyl-d-glucamine (NMDG) group and characterized with SEM-EDX, FT-IR, and TGA analyses. Batch adsorption studies revealed that cellulose-based adsorbent showed a remarkable boron removal capacity (19.29 mg/g), a wide stable operating pH range (2-10), and an adsorption process that followed the Freundlich isotherm (R2= 0.95) and pseudo-second-order kinetics (R2= 0.99). In the hybrid AdED system, the optimum operating parameters for boron removal were found to be a pH of 10, a voltage of 10 V, a flow rate of 100 mL/min, and an adsorbent dosage of 4 g/L. The presence of the adsorbent in the hybrid system increased boron removal from real geothermal brine (containing 199 ppm boron) from 7.2% to 73.3%. The results indicate that the designed AdED system performs better than bare electrodialysis for boron removal from ion-rich real geothermal brine while utilizing environmentally friendly cellulose-based adsorbent.Article Citation - WoS: 33Citation - Scopus: 37Energy Production From Treatment of Industrial Wastewater and Boron Removal in Aqueous Solutions Using Microbial Desalination Cell(Elsevier, 2021) Gören, Ayşegül Yağmur; Ökten, Hatice EserAs a result of a much needed paradigm shift worldwide, treated saline water is being considered as a viable option for replacing freshwater resources in agricultural irrigation. Vastly produced geothermal brine in Turkey may pose a significant environmental risk due to its high ionic strength, specifically due to boron. Boron species, which are generally found uncharged in natural waters, are costly to remove using high-throughput membrane technologies such as reverse osmosis. Recent advances in bioelectrochemical systems (BES) has facilitated development of energetically self-sufficient wastewater treatment and desalination. In this study, removal of boron from synthetic solutions and real geothermal waters, along with simultaneous energy production, using the microbial desalination cell (MDC) were investigated. Optimization studies were conducted by varying boron concentrations (5, 10, and 20 mg L-1), air flow rates (0, 1, and 2 L min(-1)), electrode areas (18, 24, 36, and 72 cm(2)), catholyte solutions, and operating modes. Even though the highest concentration decrease was observed for 20 mg-B L-1, 5 mg-B L-1 concentration experiment gave the closest result to the 2.4 mg-B L-1 limit value asserted by WHO. Effect of electrode surface area was proven to be significant on boron removal efficiency. Employing the optimum conditions acquired with synthetic solutions, boron and COD removal efficiencies from real geothermal brine were 44.3% and 90.6%, respectively. MDC, being in its early levels of technology readiness, produced promising desalination and energy production results in removal of boron from geothermal brine.