Hydrochemical,isotopic, and reservoir characterization of the Pasinler (Erzurum) geothermal field,eastern Turkey

The reservoir temperature and conceptual model of the Pasinler geothermal area, which is one of the most important geothermal areas in Eastern Anatolia, are determined by considering its hydrogeochemical and isotope properties. The geothermal waters have a temperature of 51 °C in the geothermal wells and are of Na–Cl–HCO₃ type. The isotope contents of geothermal waters indicate that they are of meteoric origin and that they recharge on higher elevations than cold waters. The geothermal waters are of immature water class and their reservoir temperatures are calculated as 122–155 °C, and their cold water mixture rate is calculated as 32%. According to the δ¹³C_VPDB values, the carbon in the geothermal waters originated from the dissolved carbon in the groundwaters and mantle-based CO₂ gases. According to the δ³⁴S_CDT values, the sources of sulfur in the geothermal waters are volcanic sulfur, oil and coal, and limestones. The sources of the major ions (Na⁺, Ca²⁺, Mg²⁺, Cl^?, and HCO₃ ^?) in the geothermal waters are ion exchange and plagioclase and silicate weathering. It is determined that the volcanic rocks in the area have effects on the water chemistry and elements like Zn, Rb, Sr, and Ba originated from the rhyolite, rhyolitic tuff, and basalts. The rare earth element (REE) content of the geothermal waters is low, and according to the normalized REE diagrams, the light REE are getting depleted and heavy REE are getting enriched. The positive Eu and negative Ce anomalies of waters indicate oxygen-rich environments.     

The Starzach site in Southern Germany: a site with naturally occurring CO<Subscript>2</Subscript> emissions recovering from century-long gas mining as a natural analog for a leaking CCS reservoir

In this paper, we present the Starzach site, a region featuring numerous natural CO₂ emission spots, such as mofettes, that reappeared after a longer period of extensive industrial CO₂ mining. We discuss the results of a detailed literature study on the geological setting and the activities related to the gas mining in combination with own measurements to introduce the site as an example on how gas leakage from an insecure CCS reservoir could manifest at the surface. The site is in particular interesting for such investigations as the CO₂ emissions started to replenish after the end of the CO₂ mining and offers the unique possibility to investigate an increase in degassing activity as it might be expected for an active CCS site where leakage is suspected. Based on the geological setting and soil, gas emission, and isotope investigations, we further discuss the source of the CO₂ emission and the gas ascent to the ground surface via deep-reaching faults, latter being so far excluded by previous work. The combination of our extensive literature review and recent field investigations allowed us to draw new geological conclusions for the site that were under discussion for a long time and to give insight into the site’s potential for CCS-related analog studies in the future.     

Porosity and wave velocity evolution of granite after high-temperature treatment: a review

The evolution of porosity and changes in wave velocity in granite after high-temperature treatment has been experimentally investigated in different studies. Statistical analysis of the test results shows that there is a temperature threshold value that leads to variations in porosity and wave velocity. At a temperature that is less than 200 °C, the porosity of granite slowly increases with increases in temperature, while the wave velocity decreases. When the temperature is greater than 200 °C (especially between 400 and 600 °C), the porosity quickly increases, while the wave velocity substantially decreases. The temperature ranges of room temperature to 200 and 200–400 °C correspond to the undamaged state and the micro-damage state, respectively. The results confirm that there is an important link between the variations of physical and mechanical properties in response to thermal treatment. By studying the relationships among rock porosity, wave velocity and temperature, this provides the basis for solving multi-variable coupling problems under high temperatures for the thermal exploitation of petroleum and safe disposal of nuclear waste.     

Biosorption with autochthonous and allochthonous fungal biomasses for bioremediation and detoxification of landfill leachate

Landfill leachates are not adequately treated in traditional wastewater treatment plants, on account of their problematic peculiarities: i.e., dark colour, high concentration of recalcitrant pollutants and COD, and high toxicity. In this work, 19 biomasses (15 autochthonous and 4 allochthonous) were exploited in biosorption treatment for the remediation of a leachate (influent) and the effluent coming from the biological oxidation with activated sludge and nitrification–denitrification treatment. The effects of the initial pH, the biomass amount, and the medium for the biomass pre-culture were considered. The best configuration was: pH 5, 5 g L^??1 biomass cultivated on STY medium. Eventually, the two most effective biomasses, Cunninghamella bertholletiae MUT 2861 and Aspergillus fumigatus MUT 4050, were used in consecutive 2 h cycles in a batch biosorption experiment. The effectiveness of the treatment decreased in subsequent cycles in terms of decolourisation (31–15%). COD, Cl^?, SO₄^2?, total N, and toxicity were removed mainly in the second cycle of treatment (up to ??36, ??12, ??15, ??17 and ??49%, respectively). The results suggest that the effluent toxicity was basically due to uncoloured substances, which were mainly removed after coloured molecules.     

Hydrothermal alteration and evolution of Zr-Th-U-REE mineralization in the microgranite of Wadi Ras Abda,North Eastern Desert,Egypt

Ras Abda plutonic suite, North Eastern Desert of Egypt, consists predominantly of Neoproterozoic calc-alkaline older granites. Minor exposures of pink microgranite are occurring along Wadi Ras Abda within the older granites. Previous studies on this area demonstrated that the microgranite is altered in some parts and contains anomalous concentrations of rare metal elements (Zr, Th, and U). These altered and mineralized zones are re-assessed using field observations, chemical analysis, and by the application of various transmitted light and electron microscopic techniques. The rare metals exist as mineral segregation grew freely into open cavities of the microgranite and concordant with the NNE strike-slip fault movement. The mineralized zones contain an assemblage of secondary magnetite, zircon, uranothorite, columbite-(Mn), fergusonite-(Y), and allanite-(Ce). The extreme abundance of zircon in the mineralized zone, along with other evidence, indicates a hydrothermal origin of this zircon together with associated rare metals. The geochemical investigation and mass balance calculations revealed extreme enrichment of Zr, Th, U, Y, Nb, Ta, and REE. Post-magmatic hydrothermal alterations resulted in such pronounced chemical and mineralogical heterogeneity. The hydrothermal fluids are thought to be oxidizing, alkaline and of medium temperature (>?250 °C). The average contents of the elements Zr (1606 ppm), Th (1639 ppm), U (306 ppm), Nb (955 ppm), and REE (1710 ppm) in the mineralized microgranite reach sub-economic levels and could be a potential source of these elements.     

Spatio-temporal variations of respirable particles at residential areas located in the vicinity of opencast coal projects,India: a case study

The objective of the study is to investigate spatio-temporal variations of PM₁₀, PM_2.5, and PM₁ concentrations at seven residential sites, located in the vicinity of opencast coal projects, Basundhara Garjanbahal Area (BGA), India. Meteorological parameters such as wind speed, wind direction, relative humidity, and temperature were collected simultaneously with PM concentrations. Mean concentrations of PM₁₀ in the range 215 ± 169–526 ± 412 μg m^?3, PM_2.5 in the range of 91 ± 79–297 ± 107 μg m^?3, PM₁ in the range of 68 ± 60–247 ± 84 μg m^?3 were obtained. Coarse fractions (PM_2.5–10) varied from 27 to 58% whereas fine fractions (PM_1–2.5 and PM₁) varied in the range of 51–73%. PM_2.5 concentration was 41–74% of PM₁₀ concentration, PM₁ concentration was 31–62% of PM₁₀ concentration, and PM₁ concentration was 73–83% of PM_2.5 concentration. Role of meteorology on PM concentrations was assessed using correlation analysis. Linear relationships were established among PM concentrations using least square regression analysis. With the aid of principal component analysis, two components were drawn out of eight variables, which represent more than 75% of variance. The results indicated that major sources of air pollutants (PM₁₀, PM_2.5, PM₁, CO, CO₂) at the residential sites are road dust raised by vehicular movement, spillage of coal generated during transportation, spontaneous combustion of coal, and biomass burning in village area.     

The Red Sea depositional architecture: insights from 3D modeling

More than half a century of geological and exploration studies have taken place in the Red Sea area, and still very limited information is available to the geological community in regard to the lithological distribution and the stratigraphic architecture. In this study, extensive well data was used to build the first lithologic and stratigraphic 3D models of the entire Red Sea to better understand the lithological distribution. The potential models have been constrained by bathymetric and geophysical data. Studied data demonstrate that up to 5 km of sediments were deposited in the Red Sea. It is mainly comprised of limestones, evaporites, and shales. Our models show that the evaporite body represents more than 70% of the Red Sea succession. In particular, the evaporite succession seems to be well developed in the southern region. Salt dome features are present and developed close to the margins. The models suggest that domal formation did not enable thick carbonate accumulation in some parts of the basin but the carbonate generally follows the evaporite trend. The models help to identify the main controls leading to salt diapir by highlighting the distribution of this body and the geometry of geological structures. Syn-rift faulting and rifting has been one of the most prominent structural features. Complex interplay of tectono-stratigraphic events played a significant role in shaping the stratigraphic evolution of the Red Sea basin with multiple evolution phases of paleoenvironment and paleogeographic were recognized based on the models. Our synthesis and interpretation support that moderately deep marine conditions dominated in the Miocene, whereas shallow seas dominated the whole basin during the Plio-Pleistocene period as a result of episodic marine invasion. However, lacustrine environment may have prevailed at the Oligocene time in isolated half grabens.     

Effect of climate change on water resources in the Yuanshui River Basin: a SWAT model assessment

The Yuanshui River Basin is one of the most important river basins ensuring food production and livelihoods in the Hunan and Guizhou Provinces of China. Based on digital elevation model, land use, soil, and meteorological data, the soil and water assessment tool was used to analyze the response of water resources in the basin to climate change. Specifically, the monthly runoff from the Yuanshui River Basin was simulated. Runoff measurements from the 1961–1990 series were used to calibrate model parameters, and measurements from the 1991–2010 series were used for model validation. The Nash–Sutcliffe efficiency coefficient, correlation coefficient, and water balance error were used to evaluate the simulation results; the values obtained for these parameters were 0.925, 0.929, and 2.0%, respectively, indicating that the established model can be applied successfully to runoff simulations. To evaluate the effects of climate change and human activities on runoff, 24 different climate scenarios were modeled. By comparing the model simulation results with the baseline scenario, the effects of climate change were analyzed by year, during the dry season, and during extremely dry conditions. The results showed that runoff decreased with increasing air temperature and decreasing precipitation, and that the effects of rainfall on runoff were greater than those of air temperature. Under the same baseline conditions, the effects of climate change on runoff were most pronounced during extremely dry months.     

Land readjustment for minimizing public expenditures on school lands: a case study of Turkey

Education infrastructure issues have been one of the most important topics in developing countries that have difficulty reserving money for education infrastructure needs, especially Turkey. Development plans have a crucial role in meeting school infrastructure needs in Turkey. Generally, the expropriation method has been used for land transitions from private to public ownership. However, scarcity of monetary resources for such land transitions and legal/technical deficiencies delays the process. The main objectives of this paper are to respond to the need of the education sector by using land management tools and to identify the most suitable land management tool for allocating basic and primary school lands free of charge. Current trends, education indicators, management responsibility and financial resources, statistical and economical information, education infrastructure needs, and qualitative-quantitative characteristics of the pupils in the Turkish education system are analyzed based on national and international reports. Then, the property right problems experienced in the process of allocating school lands are defined. Methods of transferring school lands to public ownership are examined, and the benefit-cost relationships are revealed. Land readjustment (LR) would make an important contribution to planning decisions and the implementation stage in the sustainable management of school lands.     

Aerosol-trace gases interactions and their role in air quality control of Delhi city (India)

Atmospheric dust is considered to be the major cause of poor air quality due to its contribution to high particulate levels, but their interaction with the acidic gases helps in controlling the level of SO₂ and NO₂ through ambient neutralization reactions. In the present study, the interaction of acidic gases such as SO₂ and NO₂ with alkaline dust was investigated during October, 2013–July, 2014 at a site named as Babarpur located at the Trans-Yamuna region of Delhi. The concentration of SO₂ ranged from 10 to 170 μg/m³ with an average of 36 μg/m³ while that of NO₂ ranged from 15 to 54 μg/m³ with an average of 26?±?8 μg/m³. The results were observed to be well within the National Ambient Air Quality Standard (NAAQS) limits prescribed by the Central Pollution Control Board (CPCB). The average concentrations of SO₂ during day and night time were recorded as 31?±?18 and 43?±?53 μg/m³ respectively while the mean concentrations of NO₂ during day and night time were recorded as 26?±?7 and 27?±?12 μg/m³ respectively. A positive correlation between SO₄^2? and NO₃^? was also observed indicating their secondary aerosol formation. In aerosol phase, average concentrations of SO₄^2? during day and night time were 3.9?±?0.3 and 6.5?±?2.3 μg/m³ respectively while that of NO₃^? were 9.5?±?1.5 and 7.3?±?0.5 μg/m³ respectively. Molar ratios of Ca²⁺/SO₄^2?, NH₄⁺/SO₄^2?, and NH₄⁺/NO₃^? were observed as 8, 5, and 1.7 during daytime and 1.5, 0.4, and 0.8 during nighttime respectively. Such molar ratios confirmed high concentrations of sulphate (SO₄)^2? and low concentrations of nitrate (NO₃^?) during night time, thereby indicating different pathway of aerosol formation during day and night time. Surface morphology and elemental composition of aerosol samples showed various oval, globular, and platy shapes where the diameter varied from few nm to ~5 μm depending on their precursors. There were certain shapes like grossularite, irregular aggregate, grape-like, triangular, and flattened which indicate the crustal origin of aerosols and their possible role in SO₂ and NO₂ adsorption.