The proper management of construction and demolition wastes (CDWs) involves understanding their origins, generation, and efficient collection methods. This is especially crucial in developing countries experiencing rapid urbanization and industrialization, where new construction and the reconstruction of older, lower-quality buildings are common practices. Governmental encouragement for the reconstruction of weak buildings, often due to dangerous conditions or natural disasters like earthquakes, further contributes to the generation of vast amounts of CDWs. In this study, the masses and volumes of CDWs resulting from the Kahramanmaras and Hatay earthquakes that occurred on February 6th, 2023, and the anticipated Istanbul earthquake in Turkiye were estimated. Additionally, the amounts of mineral fraction wastes (MFWs) and scrap iron wastes (SIWs) within these CDWs were calculated, along with their economic values. The quantitative estimations of waste generation for CDW were determined as 396,473,616 tons and 293,684,160 m3 for Kahramanmaras and Hatay earthquakes, and 393,456,358 tons and 291,449,154 m3 for the anticipated Istanbul earthquake, respectively. The economic values of recyclable materials (MFWs and SIWs) were calculated as 935,677,734 and 1,268,715,571 for Kahramanmaras and Hatay earthquakes, and 928,557,005 and 1,259,060,346 for Istanbul, respectively.

This study evaluates the levels of natural radioactivity in surface soil samples across all districts of Mardin Province, Turkiye, using data from the Turkish Environmental Radioactivity Atlas. The activity concentration levels of Ra-226, Th-232, K-40, and Cs-137 were re-mapped, and radiological parameters (Raeq, DR, Hex, AEDE, AGDE, and ELCR) were calculated for an environmental risk assessment. The average Ra-226 concentration (33.66 Bq·kg−1) exceeded the Turkiye average but remained near the UNSCEAR global median. The Th-232 concentration (29.37 Bq·kg−1) was lower than both reference values, while K-40 (385.63 Bq·kg−1) was below the Turkiye average but higher than the global median. The Cs-137 concentration (20.52 Bq·kg−1) surpassed the Turkiye average, with the highest value detected in Yeşilli district of Mardin (75.05 Bq·kg−1), suggesting an anthropogenic influence. The radiological parameters indicated that the Raeq and Hex values remained within safe limits across all districts. However, the DR and AEDE exceeded UNSCEAR global medians in Ömerli and Midyat, while the AGDE was elevated in six districts. The ELCR surpassed the global median only in Ömerli. The districts of Artuklu, Derik, Kızıltepe, Mazıdağı, Midyat, and Ömerli exhibited higher natural radioactivity, whereas Dargeçit, Nusaybin, Savur, and Yeşilli had lower risk levels. Nusaybin was identified as the least radiologically hazardous district. Given these findings, radiological parameters should be considered when selecting new residential areas. Further studies with an increased number of soil samples are recommended for a more precise environmental risk assessment.

Deniz suyu birçok endüstride termik işlemlerin soğutma ve ısıtma işlemlerinde kullanılabilmektedir. Sıcak proseslerde daha yaygın olan soğutma işlemidir ve soğutma suyu kullanımına ihtiyaç duyulur. Bununla birlikte, yeniden gazlaştırma operasyonları gibi bazı endüstrilerde ısıtma da önemli bir süreçtir. Özellikle, açık çevrimli deniz suyuyla ısıtma sistemleri, sıvılaştırılmış doğal gaz (LNG) alım terminallerinde yaygın olarak kullanılabilmektedir. Bu sistemlerden soğuk su deşarjları oluşur ve bunlar deniz ortamına geri dönerler. Soğuk su deşarjları, deniz organizmaları arasında soğuk şokuna ve hipotermiye neden olabilir. Soğuk su deşarjlarının olumsuz etkilerinden dolayı, deniz ortamındaki soğutulmuş deniz suyunun seyreltilmesi için soğuk su deşarj sistemleri kullanılabilir. Soğuk su deşarjları, boru hattı sistemleri de dahil olmak üzere tek portlu veya çok portlu difüzörler olarak tasarlanabilir. Deşarj edilen soğuk su, denizde negatif yüzer jetler olarak davranırlar. Negatif yüzer soğuk su deşarjlarının uygun şekilde seyreltilmesini sağlamak zorlu bir konudur ve ayrıntılı bir tanımlama aşaması gerektirir. Soğuk su gibi yoğun jetler, deniz ortamında dibe batma eğilimindedirler. Dolayısıyla, tasarım çalışmalarında dikkate alınan soğuk su jetinin birinci seyrelmesini taban ile jet arasında oluşan etkileşim önemli ölçüde etkiler. Difüzör, tabana yeterince yakın yerleştirildiğinde jet ile taban arasındaki sınır etkileşimi artacaktır. Bu tip durumlarda, sınır etkileşiminin çarpma noktası seyrelmesi üzerine etkisinin belirlenmesi gerekir. Bu çalışmada, deneysel olarak gerçekleştirilen iki farklı difüzör yüksekliği ile aynı koşullarda USEPA VP-UM3 sayısal modeli kullanılarak elde edilen sonuçlar karşılaştırılmıştır. Bu çalışma sonucunda USEPA VP-UM3 modelinden elde edilen çarpma noktası seyrelmelerinin, soğuk su deşarjı tasarımında yaklaşık %44 daha konservatif bölgede kaldığı belirlenmiştir.

Dams and hydraulic structures are built on rivers in order to protect water resources due to global warming, to collect surface waters to provide drinking water and/or irrigation water, to prevent floods and to establish hydroelectric power plants. Dams, for example, are hydraulic structures that have more or less positive or negative environmental interactions on surface water and groundwater. One of the environmental interactions of dams and similar hydraulic structures is the seepage of accumulated water in its reservoir from upstream bottom of the dam. This seepage can affect the level and location of groundwater, reduce the accumulation of water in the reservoir, and cause piping in the ground below the construction of the dam body. In order to control the seepage, the methods of increasing the seepage length by using sheet pile and clay blanket on the dam foundation are frequently used. In this study, in the physical laboratory model, the variations in the seepage lengths that occur under the hydraulic structure section in the soil with two different grain diameters of 0.85 mm and 1.5 mm, depending on the dam structure, soil and barrier structures (sheet pile and upstream clay blanket), were experimentally investigated. As a result, it was determined that the seepage occurs less in the soil with a smaller grain diameter of 0.85 mm, the smaller the soil particle diameter has a reducing effect on the seepage, and the use of sheet pile increases this effect positively. In addition, it has been determined that the clay blanket in the upstream is effective compared to the general conditions, but the use of sheet pile provides the most efficiency.

Radionuclides Ra-226, Th-232, and K-40 can be found in various concentrations in the surface soil. High concentrations of radionuclides in the surface soil may cause radiological risks. This study investigated natural radioactivity levels and artificial radionuclide (Cs-137) levels in the Istanbul University-Cerrahpasa, Avcilar region, Istanbul, Turkey. Radioactivity concentrations were analyzed using the gamma-ray spectrometer. The mean activity concentration of Ra-226, Th-232, K-40, and Cs-137 is 28.55, 29.57, 385.72, and 3.09 Bq kg(-1), respectively. Radiological parameters radium equivalent activity, absorbed dose rate, annual effective dose equivalent, external hazard index, and excess lifetime cancer risk were calculated using activity concentrations. The radiological parameters values were lower than UNSCEAR values, except for the annual gonadal dose equivalent (approximately 10% higher). There is a strong correlation between radiological parameters and radionuclides. Generally, the activities of radionuclides in the region fall within the recommended limits, thus Istanbul-Avcilar region can be considered safe for settlement.

Open-cycle cooling water systems and their discharges 'thermal wastewater outfalls' can be commonly used by seaside-located thermal power plants. Lower dilution performance having thermal wastewater outfalls may be one of the sources of greenhouse gas water vapour evaporation. Thermal wastewater jets of outfalls are positively buoyant, and they are commonly discharged from horizontally located nozzles on multi-port diffusers. In this study, impact point dilution increments of thermal wastewater singular jets (+10 degrees C heated) were investigated under the conditions of originally horizontally located, then downward inclined nozzle conditions using US Environmental Protection Agency-Visual Plumes model system for receiving water densities between 1,015-1,035 kg/m(3). Nozzle downward inclination angles of thermal discharges and impact point dilution increment ratios were found as in the range between for 12 degrees-13 degrees: 0.3 and 1.2, for 13 degrees-15 degrees: 0.6 and 2.6, and for 14 degrees-20 degrees: 1.5 and 6.3 for nozzle diameters of 0.1 m, 0.2 m, and 0.5 m, respectively.

Cement is a composite material and it consists of different raw materials. The raw materials which are used in the cement production industry are commonly obtained from rocks such as limestone, gypsum, clay, and iron ore. In addition, the cement raw materials may also include natural radionuclides such as Ra-226, Th-232, and K-40, which may have an adverse effect on human health. Hence, determination of natural radioactivity level is very important for human health safety. In this study, natural activity concentrations of Ra-226, Th-232, and K-40 are investigated in cement and cement raw materials in Turkey as a case study. In addition, eight different radiological parameters and indices were calculated from activity concentrations. The natural radioactivity due to the presence of Ra-226, Th-232, and K-40 was measured using the gamma spectrometer coupled with HPGe detector. The mean measured activity concentrations of Ra-226, Th-232, and K-40 in the raw materials were 38.14, 92.66, and 636.63 Bq kg(-1), respectively, with higher activity concentrations in coal for Ra-226 and trass for Th-232 and K-40. Mean activity concentrations of natural radionuclides (Ra-226, Th-232, and K-40) in cement samples were found as 34.26, 58.2, and 512, respectively. The results showed that coal and fly ash are the principal contributors for the presence of Ra-226 activity concentration, trass and iron ore materials for the presence of Th-232, and clay and trass raw materials for the presence of K-40 in cements.

In this study, geo-accumulation index (I-geo), enrichment factor (EF), potential ecological risk (Er), and risk index (RI) of five metals (Cu, Pb, Zn, Hg, and Cd) and Sc (as reference element for enrichment factor calculation) in soil samples were applied for assessing the pollution pattern and possible sources of heavy metals. Soil samples were collected from 27 different locations in Avcilar in the European part of Istanbul, Turkey. The mean I-geo values of Cu, Pb, Zn, Hg, and Cd were found between 0.12 and 0.96, which means that the soil contamination levels of these metals were uncontaminated to moderately contaminated. The EF mean values of Cu, Pb, Zn, Hg, and Cd were 1.70, 1.30, 1.30, 2.29, and 1.26, respectively. These EF results indicated that Cu, Pb, Zn, and Cd in the study area soil were affected by natural sources, whereas Hg was mainly caused by nature and partly influenced by human activities. The order of the mean values of Er in the soil samples was in the following descending order of Hg > Cd > Cu > Pb > Zn. Most of the soil samples showed low and moderate ecological risks.

Rhodamine B (RhB) as a dye tracer is widely used both in laboratory scale and in-situ studies about determination of wastewater plumes' movement and their dilution characteristics in marine environments. RhB added salt (mainly NaCl) water solutions are used on brine outfall laboratory physical model experiments. Some of the experiments in laboratory tanks can be conducted via taking samples inside the discharged brine jets. Taken samples can be measured by optical methods such as ultraviolet visible spectrophotometry for determination of dye tracer concentrations and dilution levels. However, absorbance specifications of a dye tracer, like RhB, might be affected by high concentrations of NaCI in discharge solutions. This study, aimed at determining the effect of variable NaCl concentration, which represents the discharged solutions, on prepared with RhB as a dye tracer which are diluted with distilled water in the laboratory. Absorbance levels of variable dilutions of source discharge solution were obtained and their differences were compared with different levels of NaCI concentrations. In order to decrease the experimental errors for tap water used in lab scale dye tracer studies, a mathematical expression for Salinity (S)-Absorbance (I)/Concentration(c) relation was suggested in the studied range for salinity 30-100 ppt.

In this study, effects of shallow water depths on initial dilution levels of heated water discharge from thermal effluent outfalls concerning water surface boundary effects using an inclined circular port were investigated.Receiving water environment was selected as stagnant and uniform characteristics.The inclination angle of discharge port was θ = 60°.Normalized port depths, H/dF, which was obtained from water depth (H) over port diameter (d) multiplied by densimetric Froude number (F) of jet defined as dF, were calculated for experimental set-ups.H/dF values were 3.871, 1.545, 1.160, 0.774, and 0.388 from deep to shallower depths, respectively.Rhodamine B was used as tracer of experiments.Normalized forms of impingement point horizontal distance values, x i /dF, and vertical distance values, y i /dF were decreased according to decreased water depths, H/dF.According to obtained results of this study, jet impingements occurred in the upper boundary of the receiving water body and they got closer to the nozzle when H/dF values decreased.In addition, the decreasing H/dF values caused a decrease in dilutions of horizontal distances for both complete jet centerlines (especially impact points compared to experimental) and VP estimates of free jet conditions.According to this study, VP dilution estimations were found very close to experimental impingement point dilutions no matter how VP software originally designed for only free jet conditions.This study suggests VP UM3 model can calculate realistic and conservative jet centerline dilutions at the impingement point in very limited depths in the range of normalized water depth ratio H/dF between 0.388 and 1.545.

Domestic wastewater marine outfall diffusers can be set up with sharp-edged circular ports. These simple and cylindrical ports opened on diffuser pipe wall have two main types: (1) sharp-edged port in thin-walled diffuser pipe (TN) and sharp-edged port in thick-walled diffuser pipe (TK). Because of less minor head loss, TK has 20% higher flow rate capacity than TN in same hydraulic head condition. No matter how TKs are better than TN type, TK type ports are still open-ended holes in very dynamic seawater ambient. TK ports suffer from clogging risk because of sediment transportation and seawater intrusion into diffuser pipe during less wastewater flow rate periods. In order to protect TK ports, an elastomer and one-way flow providing "duckbill" check valve (DBV) with same nominal size can be mounted on circular ports. This rehabilitation method could specifically be applied on domestic wastewater discharging marine outfalls after start of their operational period. However, additional DBV part could change original hydraulic and initial dilution conditions, due to increased minor head losses and jet velocities. In this study, TK to DBV nozzle type conversion effects on initial dilution were discussed. Q = 0.5 m(3)/s design flow rate, t = 30 years lifespan, H = 20-50 m port depths, and rho = 1,015-1,035 kg/m(3) receiving water densities, 12 different diffusers with d = 150 mm diameter sized TK circular ports were designed and converted to 150 mm regular (not wide type) DBV nozzles. All hydraulic parameters and initial dilutions of before and after DBV usage were recalculated from literature data for line source in this study. Initial dilution comparisons between original and DBV converted conditions as Delta S (%) were varied from -10.77 to 6.53 for at the end of lifespan, t = 30 years with 33% positive values. For the first days of life span, t = 0 year, Delta S (%) were varied from -9.10 to 10.94 range with 50% positive values.

The natural radioactivity levels and some radiological parameters of Turkish Portland cements (PC) originated in various regions were determined in this study. The activity concentration of cement samples for 226Ra, 232Th, and 40K were measured using a gamma-ray spectrometer with high purity germanium radiation detector. The PC samples had activity concentrations of 33.0, 16.7, and 239.5 Bq kg−1 for 226Ra, 232Th, and 40K, respectively. The mean value of radium equivalent value (Raeq) was found to be 75.4 Bq kg−1. The radium equivalent values in the cement samples were lower than the acceptable level of 370 Bq kg−1. The calculated radiological parameters were found to be below the acceptance levels.

Most of the domestic wastewater discharging marine outfall diffusers have simply opened circular ports on the diffuser pipe wall. In order to protect the diffuser from seawater intrusion and clogging by sediments during lower flow rate periods, duckbill check valve (DBV) can be mounted on circular ports. Because of the DBV use instead circular ports at the same conditions, jet velocity at port could be increased. It was reported in some of the studies that the initial dilution was also increased in changed diffusers with DBVs. In this study, the initial dilution estimations of multiport diffusers were compared before and after DBV mounted conditions of horizontally opened circular sharp edged ports on the thin pipe wall. For Q=0.5m(3)/s design flow rate, t=30-year lifespan, H=20-50m port depths and, (a)=1,015-1,035kg/m(3) receiving water densities, 12 different diffusers with d=150mm diameter sized circular ports were designed. With the same total head, all diffusers were converted to 150-mm DBV nozzles. All hydraulic parameters and initial dilutions of before and after DBV usage were recalculated from the literature data for line source in this study. Dilution comparisons for the end of the project were shown that all DBV used results were lower than circular port results as S (%) from -0.19 to -19.18 ranges. Except for two of the lower density values at the shallowest port depths, S (%) had similar results for project start year.

In this study, the effect of bottom depth interaction on initial dilution differences of cold water discharge was experimentally investigated. 5 degrees C cooled and dye tracer added cold water were horizontally discharged from a submerged circular nozzle from an elevated position into a stagnant and homogeneous receiving water in an experimental tank. Minimum initial dilutions were measured in cold water jet centreline in jet body and density current. Jet boundaries and geometric parameters were obtained from instantaneous image series of cold water jets. According to this study, for 24.54% decrease of normalised nozzle-bottom distance, y(0)/dF, normalised impact point distance, x(i) / dF was 24.43% decreased, and normalised impact point dilution, S-i / F was 13.65% decreased.

Three‐dimensional laser‐induced fluorescence (3D LIF) was applied for the first time to investigate hydrodynamics and mixing in an ozone contactor used for water disinfection. The unsteady, three‐dimensional flow and mixing in the contactor was visualized and quantitatively analyzed, providing information that has not been possible to supply with traditional tracer techniques. In particular, the results obtained from a model reactor with a sidestream venturi injection suggested that the overall reactor hydrodynamics were close to a plug flow despite the jet injection at the inlet. The inflow separated into two streams as it reached the opposite wall, and the streams swirled as they traveled through the reactor, allowing a “plug‐flowlike” condition to develop in each water stream. The 3D LIF technique is expected to be useful for the design and optimization of ozone contactors and other disinfection reactors, including chlorine contactors and ultraviolet reactors.

Air Pollution emissions due to motor vehicle-related traffic on motorways are sent into the atmosphere. Along with many pollutants from motor vehicles because of fossile fuel usage, heavy metals are also emitted as particles with exhausted gas. Heavy metals are one of the important parameters among environmental pollution sources. Heavy metals from motor vehicles may be found as PM in motorway atmosphere and be involved in street dust by depositing on roads as atmospheric precipitates. Bridge tollhouses are one of the most closely encountered environments of human beings with this kind of dust. In this study, time-related changes of atmospheric precipitate depositing per unit area were determined on breathing height of tollhouse workers, as well as concentrations of lead (Pb), copper (Cu), zinc (Zn), cadmium (Cd), and nickel (Ni) were measured. The study area was Istanbul Bosphorus Bridge, which is one of the busiest points of the world (referred to as the junction point of Asia and Europe) after it was merged to international D-100 motorway. According to the results obtained from the samples collected in ten different times during thirteen months, average lead concentration was found to be 1454.65 mg/kg dry soil, where the concentrations of copper, zinc, cadmium, and nickel were 399.12, 2034.78, 24.37, and 140.92 mg/kg dry soil, respectively.

In this study, methane emission was measured using micro gas chromatographic methods in Hasdal and Yakacik sanitary landfill areas in Istanbul City. Methane levels were found as 27.76-36.90% in Hasdal and 13.52-51.78% in Yakacik. Methane effects oil environmental and public health were discussed.

In Istanbul, the biggest city in Turkey, a large amount of solid waste is produced by the population. The bio-degradation of these wastes deposited in regular areas lead to the evolution of landfill gases. They carry a high risk of explosion and flammability, so it is of great importance to safely remove them from solid waste landfill, or as a second alternative, to find a utility for them. In this study, the major landfill gas emissions produced in Istanbul Kernerburgaz-Odayeri solid waste landfill were investigated. In the area, CH4, CO2, and O-2 measurements were made for one year, including the monitoring of all seasonal variations. In these measurements, it was determined that methane varied from 0.2-60%, while carbon dioxide showed 0.540% change, and oxygen was found to be within 0.1-19.3%. In addition, it was found for methane that 37.5% portion of the results obtained was within 5-15% (explosion interval), while 46.25% showed higher concentrations than its flaming threshold, i.e., 15%. It will have a positive effect to conveniently remove the gases in Kemerburgaz region solid waste landfill site, in terms of reduction of global greenhouse effect and explosion risk, as well as preventing these gases to reach polluting, concentrations.