Environmental Engineering / Çevre Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/4321
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Article Citation - WoS: 3Citation - Scopus: 4Enhancing Biogas Production From Chicken Manure Through Vacuum Stripping of Digestate(Springer Heidelberg, 2023) Sengur, Ozlem; Akgul, Deniz; Bayrakdar, Alper; Calli, BarisThe vacuum stripping's combined ammonia removal and disintegration effect on chicken manure digestate was evaluated for the first time at different pH values (8.5, 9.5, and 10.5) and temperatures (30, 50, and 70 degrees C). In this way, the potential increase in biogas production by recirculating the vacuum-stripped digestate to the anaerobic digester was determined. Experimental results showed that increasing pH and temperature significantly increase TAN removal, but pH is more effective. A significant portion of the ammonia was removed in the first 30 min. Therefore, a second set of stripping tests was performed for 30 min and at 70 degrees C and pH 10.5. After 30-min tests, a biomethane potential (BMP) assay was performed using the vacuum-stripped digestate to determine how vacuum stripping affects biomethane production. Despite having the lowest disintegration efficiency, the highest biomethane potential (56.2 +/- 29.7 mL CH4/gVS) was obtained with the digestate, which was subjected to vacuum stripping at 70 celcius without pH adjustment, and 48.7% more methane was produced than the control set. The lower residual biomethane potential in vacuum-stripped digestate at pH 9.5 and 10.5 was attributed to Na+ inhibition resulting from high NaOH consumption for pH adjustment.Article Citation - WoS: 21Citation - Scopus: 21Remote Sensing-Based Monitoring and Evaluation of the Basin-Wise Dynamics of Terrestrial Water and Groundwater Storage Fluctuations(Springer, 2023) Khorrami, Behnam; Gündüz, OrhanThe recent dynamics of terrestrial water storage (TWS) and groundwater storage (GWS) fluctuations were investigated based on the Gravity Recovery And Climate Experiment (GRACE) observations over 25 basins of Türkiye. Coarse-resolution GRACE estimates were downscaled based on the Random Forest algorithm. The impacts of precipitation (P) and evapotranspiration (ET) on the variations of water storage were also assessed. The findings demonstrated good performance for the RF model in simulating finer resolution estimates of TWS. The results indicated a diminishing trend of TWS and its hydrologic components over all the basins from 2003 to 2020. The Doğu Akdeniz Basin with the annually decreasing TWS and GWS of 1.15cm/yr and 1.10cm/yr was the most critical basin of Türkiye. The least storage loss was observed in the Batı Karadeniz Basin with the annual TWS and GWS loss of 0.38cm/yr and 0.45cm/yr , respectively. Based on the results, Türkiye has lost, on average, an estimated 5.16km3/yr and 4.09km3/yr of its TWS and GWS, respectively, which are equivalent to the total storage loss of 92.88km3 and 73.62km3 of TWS and GWS during the last 18 years. The results also indicated that P and ET interact differently with the variations of TWS and GWS. The net water flux was revealed to be partially correlated with the total water storage fluctuations, suggesting the governing role of other deriving forces particularly the anthropogenic factors in the spatiotemporal variations of Türkiye’s water storage; therefore, a sector-specific analysis of the water storage variations is crucial for the country, particularly by concentrating more on the dynamics of GWS. Graphical Abstract: [Figure not available: see fulltext.]. © 2023, The Author(s), under exclusive licence to Springer Nature Switzerland AG.Article Citation - WoS: 1Citation - Scopus: 1Groundwater Recharge Estiaton in the Alaşehir Sub-Basin Using Hydro-Geochemical Data; Alaşehir Case Study(Springer, 2021) Tonkul, Serhat; Baba, Alper; Şimşek, Celalettin; Demirkesen, Ali CanThe issue of groundwater recharge has gained importance in countries where there is not enough water supply to the aquifer. However, groundwater recharge is a difficult parameter to determine. This difficulty stems from factors such as the location of the area to be studied, time, cost, and hydrological data. Numerical, isotope, and chemical approaches are used in groundwater recharge investigations. Numerical and chemical approaches are more costly and time-consuming than chemical approaches. This study aims to ascertain alluvial aquifer recharge in Alaehir (Manisa) sub-basin using chemical approaches (Chloride Mass Balance Method) and its applicability. For this purpose, research wells were drilled at 25 different points in the alluvial aquifer, water sampling was done in wet and dry periods, and rainwater water samples were collected. Groundwater recharge was calculated by using chemical approaches from the chloride concentrations of the water samples collected. An annual average of 74.84 mm of recharge was found in the Alaehir sub-basin. This value corresponds to 16.38% of annual rainfall. At the same time, it was examined the groundwater and geothermal mixing mechanism to demonstrate the applicability of the Chloride Mass Balance Method. It was concluded that geothermal fluid in Alaehir sub-basin mixed with groundwater at a rate of 17%.Article Citation - WoS: 5Citation - Scopus: 7Effect of High Salinity and Temperature on Water-Volcanic Rock Interaction(Springer, 2021) Gören, Ayşegül Yağmur; Gören, Ayşegül Yağmur; Topçu, Gökhan; Demir, Mustafa Muammer; Demir, Mustafa M.; Baba, Alper; Baba, AlperIn order to understand the processes occurring in natural hydrothermal systems, it was carried out a series of water-volcanic rock interaction studies in the laboratory and an intermediate volcanic rock samples from geothermal production wells in Tuzla geothermal field (TGF) in western Turkey. A high-pressure autoclave was used to conduct water-rock interaction experiments under similar conditions of the field. Rainwater and seawater were treated with volcanic rocks at 140 degrees C (reservoir temperature) and 4.5 bar pressure. The change in the ionic content of the resulting fluids was examined in terms of the type of volcanic rocks and mineral saturation index. The results indicate that talc and diopside minerals in geothermal systems may cause scaling at high temperatures depending on the geothermal fluid and pH.