Civil Engineering / İnşaat Mühendisliği
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Review Citation - WoS: 14Citation - Scopus: 25Sustainability of Water, Sanitation, and Hygiene: From Prehistoric Times To the Present Times and the Future(MDPI, 2023) Angelakis, Andreas N.; Capodaglio, Andrea G.; Passchier, Cees W.; Valipour, Mohammad; Krasilnikoff, Jens; Tzanakakis, Vasileios A.; Suermelihindi, Guel; Baba, AlperContaminated water and poor sanitation are associated with disease transmission. Absent, inadequate, or improperly managed water resources and sanitation systems expose individuals to preventable health risks. Billions of people lack access to these basic services today and will remain in this condition for decades to come. As we are usually thinking and talking about water, sanitation and hygiene services have changed. Looking back at the history of water, sanitation, and hygiene can help us understand the challenges and opportunities of these issues and draw lessons to achieve sustainable development in the future. Throughout history, civilizations have successfully experimented with treating water and using it for drinking, sanitation, and agriculture. For example, the Minoan civilizations originally focused on water treatment and cleaning to improve the aesthetic properties of drinking water. During prehistoric times, Minoan and Indus Valley civilizations, dating back to about 2000 BC, were the first to focus on the treatment of water supplies. From the early Minoan period, they relied on rainwater collection. During historic times, Hippocrates was the first to invent and used a water filter in the form of a cloth bag, at about 400 BC, known today as the Hippocrates Sleeve. The Romans perfected existing water technologies on a larger scale and initiated their spread throughout the Empire. Hygiene in ancient Rome was promoted by the famous public baths and toilets, which were supplied with water through widely branched aqueducts that had a high standard of cleanliness for the time and were regularly maintained.Article Citation - WoS: 4Citation - Scopus: 4Destratification of Thermally Stratified Water Columns by Air Diffusers(Elsevier, 2023) Elçi, Şebnem; Hazar, Oğuz; Bahadıroğlu, Nisa; Karakaya, Derya; Bor, AslıThis study aims at improving the understanding in order to optimise an aeration system for artificial destratification to control cyanobacteria growth in the reservoirs. Previous applications for artificial destratification in reservoirs were based on installations based on computational methods, where neither the effect of air bubble size and configuration nor the effect of air density in the bubble plume could be investigated. This study seeks for an optimized design with the help of experimental and numerical analyses. In order to perform experimental studies, a novel water tank enabling the heating/cooling of the water column as desired and a diffuser system were manufactured. During the experimental studies, effect of bubble size, bubble slip velocity, and other parameters of air diffuser on destratification efficiency were investigated. Based on the nondimensional parameters, a new destratification efficiency formula is obtained by the Genetic Algorithm (GA) approach. Additionaly, the hydrodynamics of the water tank during the mixing process by air diffuser was simulated via 3D numerical model and validated with experimental results. The Eulerian multiphase model with the ‘degassing’ boundary condition and k-ω turbulence model are found to be suitable for the purposes of the study. Based on the error analysis of comparisons of the model and observations, the best configuration of air diffuser is proposed, and the numerical model is found to be successful in simulating the destratification of thermally stratified water columns by air diffuser.Article Citation - WoS: 17Citation - Scopus: 28Effect of Geogenic Factors on Water Quality and Its Relation To Human Health Around Mount Ida, Turkey(MDPI Multidisciplinary Digital Publishing Institute, 2017) Baba, Alper; Gündüz, OrhanWater-rock interactions strongly influence water quality. Waters originating from highly altered zones affect human health. Mount Ida region in western Anatolia is an example for such geogenic interactions and additional anthropogenic impacts. A water quality monitoring study was held and a total of 189 samples were collected from 63 monitoring stations to characterize the quality of water resources and its relation with human health. The results indicated that waters originating from altered volcanic rocks that are mainly used for drinking purposes have low pH, high conductivity and elevated trace element levels. In addition, a number of acidic mining lakes were formed in the open pits of abandoned mine sites in the study area and pyrite oxidation in altered volcanic rocks resulted in extremely acidic, high mineral content and toxic waters that demonstrate an eminent threat for the environmental health in the area. Overall, the water quality constituents in Mount Ida region had a spatially variable pattern and were locally found to exceed the national and international standards, mainly due to geogenic alteration zones and anthropogenic intervention.Article Citation - WoS: 19Citation - Scopus: 21Effects of Basin Activities and Land Use on Water Quality Trends in Tahtali Basin, Turkey(Springer Verlag, 2013) Elçi, Şebnem; Selçuk, PelinBi-weekly water quality data from seven monitoring stations located within Tahtali Watershed, İzmir, Turkey and digital land use/land cover data of the same watershed are analyzed in this study. To examine the changes in land use associated with urbanization, the satellite images of the main pool of the Tahtali reservoir prior to filling and subsequent to filling, respectively, are analyzed. Aerial photos of the basin taken in 1995 (October) are compared with images taken in 2005 (November) from the IKONOS satellite through use of several GIS techniques. New residential buildings, greenhouses, and industrial buildings are presented in separate layers, and changes in basin activities are quantified. The effects of urbanization on the water quality are investigated through statistical analysis. The seasonal Kendall test is applied to the water quality parameters monitored bi-weekly at seven stations within the basin for the duration 1997-2005. There was no trend in phosphorus, but there was a negative trend in boron and nitrate and a positive trend in the parameters of biological oxygen demand (BOD) and chemical oxygen demand (COD). The improvement in nitrate concentrations is attributed to the new regulations on the use of fertilizers in greenhouses. However, increase of BOD and COD concentrations is related to the growing settlement areas and industrial zones, which point to the insufficient wastewater treatment within the basin. Soil erosion within the basin is also quantified by the universal soil loss equation using available maps. Estimated total soil loss rate increased about 2. 5 times that of 1995 when the changed land use composition in 2005 is considered in the calculations.Article Citation - WoS: 22Citation - Scopus: 28Geochemical Characterization of Acid Mine Lakes in Northwest Turkey and Their Effect on the Environment(Springer Verlag, 2013) Şanlıyüksel Yücel, Deniz; Baba, AlperMining activity generates a large quantity of mine waste. The potential hazard of mine waste depends on the host mineral. The tendency of mine waste to produce acid mine drainage (AMD) containing potentially toxic metals depends on the amounts of sulfide, carbonate minerals, and trace-element concentrations found in ore deposits. The acid mine process is one of the most significant environmental challenges and a major source of water pollution worldwide. AMD and its effects were studied in northwest Turkey where there are several sedimentary and hydrothermal mineral deposits that have been economically extracted. The study area is located in Can county of Canakkale province. Canakkale contains marine, lagoon, and lake sediments precipitated with volcanoclastics that occurred as a result of volcanism, which was active during various periods from the Upper Eocene to Plio-Quaternary. Can county is rich in coal with a total lignite reserve >100 million tons and contains numerous mines that were operated by private companies and later abandoned without any remediation. As a result, human intervention in the natural structure and topography has resulted in large open pits and deterioration in these areas. Abandoned open pit mines typically fill with water from runoff and groundwater discharge, producing artificial lakes. Acid drainage waters from these mines have resulted in the degradation of surface-water quality around Can County. The average pH and electrical conductivity of acid mine lakes (AMLs) in this study were found to be 3.03 and 3831.33 μS cm-1, respectively. Total iron (Fe) and aluminum (Al) levels were also found to be high (329.77 and 360.67 mg L-1, respectively). The results show that the concentration of most elements, such as Fe and Al in particular, exceed national and international water-quality standards. © 2012 Springer Science+Business Media New York.Article Citation - WoS: 1Citation - Scopus: 2How Do Contaminated Reservoir Bottom Sediments Affect Water Quality? an Assessment Using Swim Model(Water Environment Federation, 2013) Elçi, Şebnem; Şimşek, Sinem ElifIn this study, an approach for the assessment of long term effects of contaminated sediments on the surface water quality of a future reservoir is presented. A one-dimensional sediment-water interaction model designed to simulate contaminants associated with the sediments, and the transfer of these contaminants to the overlying water column, was developed. The effect of contaminated bottom sediments on water quality was investigated under different stratification conditions. The numerical model was applied to an existing reservoir (Tahtali Reservoir) for validation and projected contaminant concentrations based on the soil and water samples collected before inundation of the land. Results were compared with the concentrations obtained from water samples collected during its operation. Next, transfer to a planned reservoir (Çamli Basin, Izmir) of four heavy metals - copper, zinc, chromium, and lead - existing in bottom sediments of the planned reservoir is modeled. A ten year projection of heavy metal concentrations for the Çamli Reservoir showed concentrations to be higher than those acceptable by the World Health Organization (WHO). Construction of a treatment facility is recommended if the reservoir is to be utilized for providing domestic water.Article Citation - WoS: 184Citation - Scopus: 233Effects of Thermal Stratification and Mixing on Reservoir Water Quality(Springer Verlag, 2008) Elçi, ŞebnemIn this study, the effect of thermal stratification on water quality in a reservoir has been investigated by field observations and statistical analysis. During the summer period, when stratification is evident, field observations indicate that the observed dissolved oxygen concentrations drop well below the standard limit of 5 mg l-1 at the thermocline, leading to the development of anoxia. The reasons for variations in the dissolved oxygen concentrations were investigated. Variations of air temperature and other meteorological factors and lateral flows from side arms of the lake were found to be responsible for the increase of dissolved oxygen concentrations. It was also observed that turbidity peaked mostly in the thermocline region, closely related to the location of the maximum density gradient and thus low turbulence stabilizing the sediments in the vertical water column. Relatively cold sediment-laden water flowing into the lake after rain events also resulted in increased turbidity at the bottom of the lake. Nondimensional analysis widely used in the literature was used to identify the strength of the stratification, but this analysis alone was found insufficient to describe the evolution of dissolved oxygen and turbidity in the water column. Thus correlation of these parameters was investigated by multivariate analysis. Fall (partial mixing), summer (no mixing), and winter (well mixed) models describe the correlation structures between the independent variables (meteorological parameters) and the dependent variables (water-quality parameters). Statistical analysis results indicate that air temperature, one day lagged wind speed, and low humidity affected variation of water-quality parameters. © The Japanese Society of Limnology 2008.