In Turkey, Southeastern Anatolia region is the highest in terms of solar radiation level. However, the provinces in the region are subject to Particulate Matter (PM) coming from the Sahara desert, the Syrian Desert and the Arabian Desert by atmospheric transport. The daily limit of PM₁₀ and PM₂.₅ set by WHO for health is often exceeded in Sanliurfa. PM₁₀ and PM₂.₅ pollutants also accumulate on the Photovoltaic (PV) panels and cause loss of PV panel performance. In this study, the effects of atmospheric dust deposition on the performance of PV panel was determined for both monocrystalline and polycrystalline technologies under Sanliurfa atmospheric conditions. Two panels with the same characteristics were used for each PV panel group from 2 different PV technologies. One of the panels in the group was cleaned by washing with distilled water every Monday while the other was not cleaned. Thus, the effect of the dust accumulation on the PV panel was determined by comparison to the cleaned PV panel. PV panel power is measured with I–V meter. Panel surface temperature, solar radiation and other meteorological parameters are measured simultaneously. The measurements were done every Monday, Wednesday and Friday at 12:00 am from May 1 to December 31, 2019. It is observed that the dust accumulation reduces the PV power output up to 8% depending on the amount of radiation. During the summer months, the power loss on the average is 4.33% for monocrystalline and 4.57% for polycrystalline. In the autumn months, it is less than 1.77%.

This study estimates air pollution at urban background level for Quito, Ecuador, using the Urban Background Model (UBM) developed at Aarhus University, Denmark. Hourly concentrations of CO, NO₂, NOₓ, O₃, PM₂.₅ and SO₂ were calculated for the year 2009. UBM performance is evaluated at six monitoring locations. The air pollution emission inventory was scaled, using calibration factors, until modeled concentrations were in line with observations. Predicted values were graphically and statistically evaluated by comparison to measurements. The statistical assessment is conducted for: Fraction of predictions within a factor of two of the observations (FAC2), Fractional mean bias (FB), Normalized mean-square error (NMSE) and Normalized absolute difference (NAD). Results show that the UBM model successfully predicts concentrations of CO, NO₂, NOₓ, O₃ and PM₂.₅ while the predicted SO₂ concentrations are unsatisfactory. PM₂.₅ modeling meets the criteria of acceptance, but their results depend largely on the regional levels, so the quality of this information is extremely relevant. The UBM model was applied for the years 2008 and 2010 using meteorological data retrieved from the modeling sites with emissions and calibration factors derived for the year 2009, showing a performance similar to that of 2009. The findings confirm the applicability of UBM to predict air pollution at the urban background level in Quito. Satisfactory results are obtained by applying meteorological data derived from any of the available monitoring stations. The unsatisfactory results for SO₂ suggest that emission data should be reviewed and that this cannot be obtained simply by scaling.

The concentrations, size distributions, and elemental compositions of atmospheric aerosol particles over a small but representative (in terms of size, population, and geographical characteristics) insular coastal city in the North Aegean Sea were measured during winter and summer. Mean PM₂.₀ and PM₁.₀ concentrations at the city centre were respectively 26 and 21 μg m⁻³ during the cold period, and 21 and 15 μg m⁻³ during the warm period. Although these concentrations are considerably lower compared to corresponding values of PM₂.₅ and PM₁.₀ recorded in large cities in the region, they are still very close to the mean annual standards set by the EU for PM₂.₅. Higher average mass concentrations (by ca. 26–36% for Total Suspended Particles, PM₂.₀ and PM₁.₀) were observed in the cold period compared to those in the warm period due to the additional emissions from domestic heating and the weaker atmospheric dilution. The elemental composition measurements showed that crustal and anthropogenic elements (i.e., K, Ca, Ti, Mg, Fe, As, S) in the collected particle samples were also enriched when polluted air masses were transported from Northeastern Turkey. These measurements also showed that natural sources contribute sea-salt and re-suspended soil to the particulate matter load in the city's atmosphere. Non-exhaust traffic emission sources were also found to be an important contributor, as indicated by the good correlations (R² = 0.40–0.91) between crustal and traffic-related elements (i.e., Zn, Cr, Cu, and Mn). Overall, PM measurements in the urban environment in the region are relatively high, being influenced by both local sources and long-transported air masses.

The mass concentrations and content of water-soluble anions (Cl⁻, NO₃⁻, SO₄²⁻) and cations (Na⁺, NH₄⁺, K⁺, Mg²⁺, Ca²⁺) in the PM₂.₅ particle fraction were measured, and an investigation of their relationship and their contribution to the total PM₂.₅ mass measured was conducted at an urban background site as part of the Croatian monitoring network for air quality located in Rijeka, Croatia. Daily samples of PM₂.₅ particle fraction were collected over 2017 on PTFE filters using a low volume sampler Sven Leckel SEQ 47/50. Mass concentrations of the PM₂.₅ particle fraction were determined by gravimetry according to the standard HRN EN 12341:2014 (EN 12341:2014). The content of water-soluble inorganic anions and cations were determined using a Thermo Scientific ICS-5000 capillary ion chromatograph. Results show that the annual average PM₂.₅ mass concentration was 9.65 μg m⁻³ and did not exceed the limit value of 25 μg m⁻³ given by the Regulation on the level of pollutants in air (OG No. 117/12). The annual average mass concentrations of ions in PM₂.₅ particle fraction was SO₄²⁻> NH₄⁺> NO₃⁻ > Ca²⁺> K⁺> Na⁺> Cl⁻ > Mg²⁺. The contributions of total anion mass and total cation mass to the total PM₂.₅ mass were 25.4% and 12.8%, respectively. The acidic property of PM₂.₅ was obtained in spring and winter and slightly acidic in summer and autumn. For a prediction of the pollutant sources, we ran a factor analysis which was performed using the statistical packages STATISTICA 13.0. After varimax rotation, the obtained four principal component factors were found to account for 86% of the variance. Factor loadings > 0.7 were considered significant.

Precipitation chemistry is important for understanding atmospheric chemistry and transportation mechanism for a region. Therefore, 6-h rain samples were collected manually on the Black Sea Region of Turkey between March 2019 and May 2019. Totally, 21 wet deposition samples were collected in 12 rainy days. The collected rain samples were analyzed by ion chromatography for ions, including Cl⁻, NO₂⁻, NO₃⁻, SO₄²⁻, Na⁺, Ca²⁺, Mg²⁺, K⁺, NH₄⁺. Volume weighted mean (VWM) concentrations of ions were calculated and were in the order of Na⁺ > Ca²⁺ > Cl⁻ > SO₄²⁻ > NO₃⁻ > Mg²⁺ > K⁺ > NH₄⁺> NO₂⁻. The pH values of individual precipitation varied from 4.70 to 8.07. Anion to cation ratio was 0.74 ± 0.34 thus it was an indication of anion deficiency. A strong correlation between NH₄⁺ and SO₄²⁻, NH₄⁺ and NO₃⁻, Ca²⁺ and SO₄²⁻, Ca²⁺, and NO₃⁻ was found in the samples due to the neutralization process. The back trajectory model was used to find the long-range sources and the influence of air masses coming from Saharan, Europe, and the Black Sea. Calcium ion was found to be an effective ion in the neutralization processes by analysis of multiple linear regression and neutralization factor calculation. Approximately 79.5% of SO₄²⁻ and 59.7% of NO₃⁻ were neutralized by Ca²⁺ and NH₄⁺. The washout mechanism for Na⁺, Mg²⁺, Ca²⁺, and K⁺ was dominantly observed on the March 12, 2019. Rainout mechanism was seen on the April 13, 2019 rain event due to the long-range transportation from Saharan Dust.

Recently, there has been renewed interest in the relationship between economic globalization and environmental pollution since various globalization indices are developed. Although several attempts have been made to investigate the impact of globalization on the environment, no known empirical research has focused on exploring the causal relationship between ecological footprint and economic globalization index (provided by KOF Swiss Economic Institute) considering also its subcomponents—trade and financial globalization indices. In this study, a new panel data technique for the causality analysis is developed (namely, panel Fourier Toda-Yamamoto approach) and applied to ecological footprint-economic globalization nexus in 14 MENA (Middle East and North Africa) countries during the period 1981–2016. The empirical results highlight that ecological footprint Granger causes economic, trade, and financial globalization for the panel. Besides, it is found that financial globalization has a predictive power to predict further values of environmental degradation in the MENA countries. The empirical results of this paper have a number of practical implications for policymakers. Especially, policymakers should be careful about implementing environmental policies since they may affect economic (trade and financial) activities negatively.

The present work describes the synthesis of α-MnO₂ nanorods using a natural extract of Brassica oleracea (cabbage) and the formulation of its nanohybrids with polycarbazole, i.e., α-MnO₂/PCz. Synergistic interaction between PCz and MnO₂ is revealed from infrared spectroscopy (IR) studies while the composition is determined by X-ray photoelectron spectroscopy (XPS). The formation of α-MnO₂ nanorods is confirmed via high-resolution transmission electron microscopy (HRTEM). The indirect bandgap of α-MnO₂ is reported as 2.5 eV while for the nanohybrids it is found to be ranging between 2.3 and 2.5 eV. Results show that 91% and 89% of degradation is achieved within 30 min and 90 min under the microwave and UV irradiation respectively. Hydroxyl radicals (•OH) and superoxide (•O₂⁻) radicals are responsible for photocatalytic degradation of the drug Bactrim DS which is confirmed by radical scavenging experiments. The nanohybrids show promising catalytic activity under UV as well as microwave irradiation.

Silver contamination of soil systems has been shown to have significant negative effects on soil microbial communities and key functional processes. However, few studies to date have addressed the influence that soil physico-chemical characteristics may have on silver toxicity. In this study, the influence of soil pH soil was investigated on the toxicity of both silver nano-(NP) and micron-(MP) particles to microbial communities and community functioning in a pastureland soil. An acidic soil, pH 5.1, was harvested from an agricultural pastureland and divided into two batches, one of which was adjusted with calcium carbonate to a neutral pH of 7. The effect of 50 mg kg⁻¹ of AgNP and AgMP amendment on the acidic soil and the neutral soil microbial communities was then examined in a microcosm-based experiment. Our results found dehydrogenase activity, which was used as a proxy measure for microbial activity, to be far more susceptible to both AgNP and AgMP contamination in the acidic soil than in the neutral soil. Additionally, both AgNPs and AgMPs significantly affected bacterial and fungal community structures in the acidic soil; however, community structures in the pH-neutral soil amended with AgNPs and AgMPs remained similar to those in the unamended control. The results from this study indicate that soil pH was an influential factor affecting AgNP toxicity in our soil system with the acidic soils far more susceptible to silver contamination than the neutral soil.

This study examines the Environmental Kuznets Curve (EKC) hypothesis in the context of 12 members of the OPEC by utilizing data on both the aggregate gross value added and the services’ sectoral value-added between 1992 and 2015. This empirical work contributes to the literature by applying the panel spatial techniques which resulted in the findings as follows. Firstly, the results verify the authenticity of the EKC hypothesis for the aggregate level of gross value added as perceived from its inverted-U shaped association with CO2 emissions. Secondly, the disaggregated analysis affirms the heterogeneity of the validity of the EKC hypothesis across the subsectors within the services sector; this justifies the importance of analyzing the EKC hypothesis from a comprehensive (disaggregated) perspective for unearthing key sector-specific policy implications. The results reveal that the EKC hypothesis holds only in the context of construction services only but not for the cases of restaurant services, tourism and transportation services. These key findings call for effective measures to be undertaken to address the adverse environmental impacts that can be attributed to thse three sub-sectors for which the EKC did not hold. In line with the overall findings from the empirical exercises, it is recommended that the concerned OPEC members reduce their monotonic dependency on the consumption of fossil fuels, oil in particular, and gradually incorporate renewable energy resources into the energy-mix particularly within their respective services sector.

This study investigates the heterogeneous causal linkages between urbanization, the intensity of electric power consumption, water-based pollutant emissions, and GRP in regional China by developing an urbanization-augmented “Stochastic Impacts by Regression on Population, Affluence, and Technology” (STIRPAT) model. A whole country panel of 29 provinces as well as region sub-panels of China, for the period 1999 to 2018, are estimated employing common correlated effects mean group approach (CCEMGA), which offers robustness against heterogeneous characteristics and cross-sectionally dependent series. From the theoretic modeling aspect, the intensity of electric power consumption and urbanization have been introduced as the determinants of water-based pollutant emissions in the STIRPAT modeling framework. Based on empirical results, first, GRP growth has shown appealing behavior in the form of its heterogeneous impacts on water-based pollutant emissions growth in the case of different regions. For instance, its impact is noted to be positive and statistically significant for the western region, which turned positive but statistically insignificant for the intermediate region. And it further turned significantly negative in the case of the eastern region. We call this phenomenon as “development level-based emission mitigation effect.” Second, in terms of the impact of GRP growth on urbanization, the “development-based urbanization ladder effect” has been found. Based on heterogeneous causal links, firstly, the existence of a positive bilateral causal link between the intensity of electric power consumption and GRP growth and urbanization and GRP growth has been validated. Secondly, a positive unidirectional causal link emerged from urbanization to the intensity of electric power consumption and water-based pollutant emissions growth. Thirdly, the causal connection between GRP growth and water-based pollutant emissions growth remained very interesting and of mixed nature. Based on empirical findings, useful policies are extended. Graphical abstract