C5–C12 volatile organic compounds at roadside,residential, and background locations in Ankara,Turkey: Temporal and spatial variations and sources

Abstract

Particle emissions of modern diesel engines are of a particular interest because of their negative health effects. The special interest is in nanosized solid particles. The effect of an open channel filter on particle emissions of a modern heavy-duty diesel engine (MAN D2066 LF31, model year 2006) was studied. Here, the authors show that the open channel filter made from metal screen efficiently reduced the number of the smallest particles and, notably, the number and mass concentration of soot particles. The filter used in this study reached 78% particle mass reduction over the European Steady Cycle. Considering the size-segregated number concentration reduction, the collection efficiency was over 95% for particles smaller than 10 nm. The diffusion is the dominant collection mechanism in small particle sizes, thus the collection efficiency decreased as particle size increased, attaining 50% at 100 nm. The overall particle number reduction was 66–99%, and for accumulation-mode particles the number concentration reduction was 62–69%, both depending on the engine load.     

Removal of 2, 4‐D from aqueous solution by the adsorbents from spent bleaching earth

Abstract

The removal of 2, 4‐D (2, 4‐ dichlorophenoxyacetic acid) from aqueous solutions by activated spent bleaching earths (SBE) was studied at 20 °C. Experiments were performed as a function of time, initial concentration, dose and particle size of the adsorbent. The Langmuir and Freundlich adsorption equations were fitted by the adsorption data obtained. The values of Langmuir and Freundlich constants were determined. The adsorption kinetic was found to follow Lagergren equation. Both the boundary layer and intraparticle diffusion played important roles in the adsorption rate of 2, 4‐D. As the size of the adsorbent increased, the time to reach equilibrium increased but adsorption capacity decreased.     

Sources of Volatile Organic Compounds in a University Building

A total of 34 volatile organic compounds (VOCs) were measured in the indoor of laboratories, offices and classrooms of the Chemical Engineering Department of Hacettepe University in Ankara in 2 week-day passive sampling campaigns. The average concentrations ranged from 0.77 to 265 μg m^?3 at the different indoor sites, with the most abundant VOC found to be toluene (119.6 μg m^?3), followed by styrene (21.24 μg m^?3), 2-ethyltoluene (17.11 μg m^?3), n-hexane (10.21 μg m^?3) and benzene (9.42 μg m^?3). According to the factor analysis, the evaporation of solvents used in the laboratories was found to be the dominant source.     

Biogeochemical cycle of arsenic and calculating the enrichment factor by using Li element

In this study, the biogeochemical cycle of arsenic in the Bosporus and the Golden Horn, which have a two-layer stratified structure, was investigated and the dominant feature in this cycle was observed to be the anthropogenic (domestic + industrial) activities. On the contrary, in the rural areas which are far from human activities, such as İğneada, the seawater–atmosphere interchange can be observed evidently in the periods covering the primary production.     

Effects of environmental hypercapnia on hemato-immunological parameters,carbonic anhydrase,and Na+, K+-ATPase enzyme activities in rainbow trout (Oncorhynchus mykiss) tissues

In this study, the effects of environmental hypercapnia on hemato-immunological parameters and the activities of respiratory enzymes such as carbonic anhydrase (CA) and Na⁺, K⁺-ATPase were investigated in rainbow trout (Oncorhynchus mykiss) tissues (gill, liver and kidney). Batches of 12 fish were exposed to 4.5 mg L^?1 (control) and 14 mg L^?1 CO₂. No mortalities occurred during the 14 days of the experimental period. Red blood cell (RBC), hemoglobin (Hb), and hematocrit (Ht) levels, and innate immune parameters such as nitro blue tetrazolium (NBT), lysozyme, and myeloperoxidase activities, and the melano-macrophage frequency were negatively affected by elevated CO₂ levels. Patterns of change in CA activity differed among the gill, liver, and kidney. Compared with the activities of CA in the control group, the CA enzyme was significantly stimulated at day 7 in the gill tissue, whereas it was stimulated at day 14 of the experiment in the liver tissue of fish exposed to 14 mg L^?1 CO₂ (P < 0.05). In contrast to the pattern of CA enzyme activities, the Na⁺, K⁺-ATPase enzymes were stimulated significantly in the liver after day 7 but inhibited in the kidney and gill (P < 0.05). These results suggest that a subchronic exposure to hypercapnia of rainbow trout tissues may lead to adaptive changes in the respiratory enzymes and negatively affects hemato-immunological parameters.     

Age Structure and Body Size Variation in Common Toad (Bufo bufo,Linnaeus 1758) from Three Different Altitudes in Turkey

Russian Journal of Ecology - We describe here for the first time the body size and age of the Common Toad (Bufo bufo) from high (Trabzon, 1090 m and Kastamonu, 925 m above sea level) and low...     

Environment as Politics: Framing the Cerattepe Protest in Twitter

Environmental protests across the globe are often studied with a particular focus on their environmental aspects, but these protests are also embedded in a local political setting shaped by governmental policies. Recent environmental protests in Turkey, which appear to be based on ecological grievances, have developed as a response to political decisions that gave priority to economic development and national interests over environmental concerns. This study examines the political character of the environmental protest in Cerattepe, and focuses on the framing practices of its players in order to see if their motivations transcended environmental concerns. The research combines framing with network analysis, and studies the propagation of frames through Twitter. It has been found that the political economic aspects became predominant in the protest network, while the frames fostered dense connections between activist groups.     

Extracting urban impervious surfaces from Sentinel-2 and Landsat-8 satellite data for urban planning and environmental management

Environmental Science and Pollution Research - Impervious surface is mainly defined as any surface which water cannot infiltrate the soil. Due to the impact of urban impervious surfaces (UIS) on...     

Application of a scenario-based modeling system to evaluate the air quality impacts of future growth

The structure and design of future urban development can have significant adverse effects on air pollutant emissions as well as other environmental factors. When considering the future impact of growth on mobile source emissions, we generally model the increase in vehicle kilometers traveled (VKT) as a function of population growth. However, diverse and poorly planned urban development (i.e., urban sprawl) can force higher rates of motor vehicle use and in return increase levels of pollutant emissions than alternative land-use scenarios. The objective of this study is to develop and implement an air quality assessment tool that takes into account the influence of alternative growth and development scenarios on air quality.The use of scenario-based techniques in land use planning has been around since the late 1940s and been tested in many different applications to aid in decision-making. In this study, we introduce the development of an advanced interactive scenario-based land use and atmospheric chemistry modeling system coupled with a GIS (Geographical Information System) framework. The modeling system is designed to be modular and includes land use/land cover information, transportation, meteorological, emissions, and photochemical modeling components. The methods and modularity of the developed system allow its application to both broad areas and applications.To investigate the impact of possible land use change and urbanization, we evaluated a set of alternative future patterns of land use developed for a study area in Southwest California. Four land use and two population variants (increases of 500k and 1M) were considered. Overall, a Regional Low-Density Future was seen to have the highest pollutant emissions, largest increase in VKT, and the greatest impact on air quality. On the other hand, a Three-Centers Future appeared to be the most beneficial alternative future land-use scenario in terms of air quality. For all cases, the increase in population was the main factor leading to the change on predicted pollutant levels.     

Removal of AOX, total nitrogen and chlorinated lignin from bleached Kraft mill effluents by UV oxidation in the presence of hydrogen peroxide utilizing TiO2 as photocatalyst

Background, aim, and scope  The pulp and paper industry is the sixth largest polluter discharging a variety of gaseous, liquid, and solid wastes into the environment. Effluents from bleached Kraft mill effluents (BKME) are polluting waters to a great extent These effluents cause considerable damage to the receiving waters if discharged untreated since they have high levels of biological oxygen demand (BOD), chemical oxygen demand (COD), chlorinated compounds (measured as AOX), suspended solids (mainly fibers), fatty acids, tannins, resin acids, lignin and its derivatives, sulfur and sulfur compounds, etc. This study aimed to remove adsorbed organic halogen (AOX), total nitrogen, and lignin-degrading products in the wastewater (4,500 m³/h) from the paper mill in the pulp and paper industry, which is discharged to sea from a plant located in western Turkey. Materials and methods  The photocatalytic degradation of AOX, total nitrogen, and chlorinated lignin in BKME have been investigated in different parameters, such as time, H₂O₂ and TiO₂ concentration. In addition, for investigating the effect of chlorine on the removal of lignin, pure lignin solution was prepared in equal amounts to chlorinated lignin degradation products found in BKME. The same experiments were conducted for this solution. Experiments were carried out in photocatalytic reactor made of Pyrex glass. The mercury lamp was used as a radiation source. All irradiation was carried out under constant stirring. The existence of dissolved O₂ is an important factor which increases the photocatalytic degradation. Hence, we used an air pump for the aeration of the wastewater solutions. The temperature of the wastewater was controlled and adjusted to 25°C by thermostat pump in conjunction with a cooler. At the end of all experiments, AOX, total nitrogen and lignin concentrations were analyzed according to standard methods. All experiments were performed in duplicate and average values were used. Results and discussion  When the effect of H₂O₂ and time were investigated, it was observed that the AOX concentration increased from 3.0 to 11.0 mg/L by only UV. However, when H₂O₂ was added, AOX concentration decreased from approximately 3.0 to 0.0 mg/L. The optimal conditions for the removal of AOX appear to be an initial H₂O₂ concentration of 20.0 mL/L and reaction time of 50 min. In addition, at the same experiment conditions, it was seen that the total nitrogen concentration decreased from 23.0 to 15.0 mg/L by only UV and by increasing H₂O₂ concentration, the concentration of 20.0 mL/L H₂O₂ appears to be optimal (9.0 mg/L). The AOX, total nitrogen and lignin degradation products and pure lignin go through a minimum when the concentration of H₂O₂ and TiO₂ increases at constant pH and UV intensity. The kinetics for the degradation of AOX, total nitrogen and lignin degradation products followed a pseudo-first order law with respect to the products, and the degradation rates (min⁻¹) for the UV/TiO₂/H₂O₂ system were higher than that of the corresponding values for the UV/H₂O₂ system. Conclusions  The AOX, total nitrogen and lignin concentration go through a minimum when the concentration of H₂O₂ and TiO₂ increases at constant pH and UV intensity. It was found that the UV/TiO₂/H₂O₂ system has proved capable of the degradation of total nitrogen as well as chlorinated and degraded lignin in BKME. Recommendations and perspectives  The photocatalytic process can be considered a suitable alternative for the remove of some compounds from the BKME. Nevertheless, further studies should be carried out to confirm the practical feasibility of BKME. Another result obtained from the study is that pre-purification carried out with UV/TiO₂/H₂O₂ photocatalytic process may constitute an important step for further purification processes such as adsorption, membrane processes, etc.