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Результаты 3361-3370 из 8,010
A spatial-temporal decomposition of carbon emission intensity: a sectoral level analysis in Pakistan Полный текст
2021
Azam, Muhammad | Nawaz, Saima | Rafiq, Zubair | Iqbal, Nasir
We examine the relative performance of the industry, services, and agriculture sectors in energy conservation and reduction in CO₂ emissions in Pakistan using the “spatial-temporal decomposition” method by taken data from 2006 to 2016. An efficient way to achieve low-carbon economy targets is to decompose different factors contributing to CO₂ emissions, including structure effect, intensity effect, GDP gap effect, energy use efficiency effect, and economic efficiency. We classify economic sectors into three groups based on performance, i.e., sectors performing below, average, and above-average performing. Our results indicate that the economic efficiency and energy use efficiency effects in the industry sector have remained above average. In contrast, the GDP gap effect has remained below average. In the case of structure effect and intensity effect, the agriculture sector has performed on average. In contrast, the service sector has shown mixed results in all factors. The government should pay special attention to energy use structure and innovation to improve desirable output technical efficiency to achieve the target carbon emission level.
Показать больше [+] Меньше [-]Health risk assessment of chromium contamination in the nearby population of mining plants, situated at Balochistan, Pakistan Полный текст
2021
Chandio, Tasawar Ali | Khan, Mohammad Nasiruddin | Muhammad, Maria Taj | Yalcinkaya, Ozcan | Turan, Eylem | Kayis, Ahmet Furkan
The main objective of this work was to investigate the root cause(s) of the various diseases in the local population, living in the proximity of chromium mining area. The analytical work was done on the samples of drinking water, soil and human blood, collected from the study area. The chosen study area is known as Muslim Bagh, located in the Balochistan province of Pakistan. The area is well-known for chromite hub. The hub comprises about 325 open-cast and underground mines, 100 dumping sites and 11 chrome beneficiation plants. The presented investigation is the first report of its nature on the contamination of heavy metals (HM) in the samples of drinking water and soil of the study area. The traces of different HM were also found in the random blood samples of human population in the study area. The amount of Co, Ni, Pb, As and Cr in the soil samples of the study area was obtained in the range of 990 × 10³–1837 × 10³, 1 × 10³–11 × 10³, 1 × 10³–15 × 10³, 84 × 10³–187 × 10³ and 6.9 × 10⁶–19.5 × 10⁶ (μg/kg ppb), respectively, whereas the samples of drinking water of the area found were 199–997 Co, 40–1370 Ni, 30–740 Pb, 47–890 As and 1990–13,530 (μg/kg ppb) of Cr. The obtained data of the physiochemical properties and the amount of HM show that the available drinking water sources are unfit for human consumption, mainly because of the chromium amount. Questionnaire analysis of the local population was also revealed that there was no awareness or feeling about metal poisoning in the targeted people and had no idea about the metal contaminations and diseases caused by this. Human health risk assessment for both carcinogenic and non-carcinogens concludes that the children and adults of the area are at high risk of several diseases and disorders.
Показать больше [+] Меньше [-]Detailed characterization, antibiotic resistance and seasonal variation of hospital wastewater Полный текст
2021
Gönder, Zeren Beril | Kara, Emel Mataracı | Celik, Berna Ozbek | Vergili, Ilda | Kaya, Yasemin | Altinkum, Serdar Mehmet | Bagdatli, Yasar | Yilmaz, Gulsum
This study investigates the presence of the different classes of micro-pollutants such as pharmaceutical active compounds (PhACs) (20 antibiotics, 8 analgesics and anti-inflammatories, 5 cytostatic agents, 7 β-blockers, 4 lipid regulators, 13 psychiatrics, 1 antidiabetic, 1 receptor antagonist, 1 local anaesthetic, 1 antihypertensive and their 5 metabolites), hormones (8 compounds), X-ray contrast agents (6 compounds), benzotriazoles (3 compounds) and pesticides (6 compounds), and antibiotic resistance in hospital wastewater (HWW) of a medical faculty in Istanbul, Turkey. In addition, the seasonal variations of the selected PhACs and X-ray contrast agents and antibiotic resistance were evaluated for 2 years in a total of eight samples. In the PhACs, sulfamethoxazole and its metabolite (4 N-acethyl-sulfamethoxazole) in the antibiotic group and paracetamol in the analgesic and anti-inflammatory group were found at 100% of frequency and the highest concentrations as 35, 43 and 210 μg/L, respectively. The mean concentrations of psychiatric compounds were found less than 0.25 μg/L except carbamazepine (1.36 μg/L). Bisphenol A in hormone group had the highest concentration up to 14 μg/L. In the hormone group compounds, 17-α-Ethinylestradiol and 17-β-Estradiol were detected at lower mean concentrations of 0.2 and 0.05 μg/L, respectively. 1H-benzotriazole had the highest concentration with the mean concentration of 24.8 μg/L in benzotriazole group compounds. The compounds in X-ray contrast agents group were noted as compounds detected at the highest concentration in HWW up to 3000 μg/L. Antibiotic resistance against azithromycin, clindamycin and trimethoprim-sulfamethoxazole antibiotics was observed around 50% in the winter period. The seasonal variation was detected for the most of the investigated PhACs, especially in antibiotic group which was in line with those significant differences in antibiotic resistance rates in the studied antibiotics between winter and summer seasons.
Показать больше [+] Меньше [-]Effect of heat treatment on the emission rate of radon from red sandstone Полный текст
2021
Li, Pengfei | Sun, Qiang | Tang, Shengli | Li, Delu | Yang, Tian
High temperature and pore structure are important factors affecting the emission rate of radon in rocks. This study mainly focused on the correlation between radon emission rate and temperature in red sandstone. The results showed that in the temperature range of 25–400 °C, as the temperature increased, the connectivity of the internal pores of the sample became better, resulting in a significantly increased radon emission rate. The radon emission rate at 400 °C was 2.86 times the original. To explain the changes that occurred in the internal structure of the samples, the porosity characteristics of the samples after heat treatment were studied by nuclear magnetic resonance (NMR). It was found that the pore structure was also an important factor affecting the rate of radon emission. The smaller pore size of the micropores (r < 0.1 μm) inhibited the emission of radon in the sandstone. These results helped in understanding the mechanism of radon emission rate and provide an important basis for predicting rock fragmentation and coal fire.
Показать больше [+] Меньше [-]Synthesis Approaches to Magnetic Graphene Oxide and Its Application in Water Treatment: A Review Полный текст
2021
Wang, Junfeng | Li, Xuerong | Tang, Linwang | Ma, Xinyu | Lu, Liuxian | Chen, Yunnen | Zhong, Changming
Magnetic graphene oxide (MGO) is an inorganic composite material composed of graphene oxide (GO) that has the characteristics of GO and magnetic material. The application of MGO in water treatment can effectively solve problems such as difficult recovery of the adsorbed GO from liquid, low efficiency, and high treatment cost, which are regarded as having important academic research value. In this study, the properties, synthesis approaches, and characterization methods of MGO, as well as its adsorption effect and the mechanism of this composite material as an adsorbent of heavy metals, organic dyes, and rare earth ions during water treatment, are comprehensively summarized. Finally, the future development of MGO as a high-efficiency adsorbent is discussed to provide references regarding application of MGO in the field of water treatment.
Показать больше [+] Меньше [-]Local dispersion characteristics of dust in large open-air piles under the action of one-way wind Полный текст
2021
Duan, Zhenya | Wang, Yan | Jiao, Qiheng | Wang, Jie | Liu, Yongzhen
A large amount of dust particles produced by the wind in an open-air pile is one of the important reasons for air pollution. Studying the law of dust diffusion in local areas is of great significance for the atmospheric particulate control. In this study, a pile of sodium carbonate in a large open-air pile in Weifang, China, is regarded as the research object. The dispersion characteristics of dust particles around the pile under the action of unidirectional wind are studied through wind tunnel test and numerical simulation. The complex atmospheric environment is simplified as unidirectional wind, and the influence of different wind speeds on the dispersion of particles with diverse sizes in the pile is studied. Although a large gap exists between the assumption and the real atmospheric environment, this study provides a reference for the evaluation of the pollution scope of blowing dust and prevention and control of pollution. Results show that a high-concentration range of the dust exists near the pile behind the wind direction and may continue to spread to the height due to the influence of a whirlpool, and the dispersion distance and width can increase with the increase in wind speed. The increase in particle diameter increases the kinetic energy loss of particles for the fluid. Under the same starting speed, the dispersion distance of dust decreases with the increase in particle diameter. With the increase in particle diameter, the dust concentration distribution presents the trend of interior hollowing and high-concentration area fragmenting.
Показать больше [+] Меньше [-]Does the pollution haven hypothesis prevail in Turkey? Empirical evidence from nonlinear smooth transition models Полный текст
2021
Bulut, Umit | Ucler, Gulbahar | Inglesi-Lotz, Roula
The pollution haven hypo thesis (PHH) postulates that foreign direct investment (FDI) inflows can increase environmental deterioration in developing countries as multinational firms tend to transfer their dirty industries to these countries. Turkey, as a developing economy, has witnessed intense FDI inflows over the last decades. Within this scope, the goal of this paper is to examine whether the pollution haven hypothesis (PHH) prevails in Turkey within the scope of the environmental Kuznets curve (EKC) hypothesis over the period 1970–2016. To that end, the paper employs unit root and cointegration methods based on the nonlinear smooth transition models. The empirical findings of the paper indicate that both hypotheses are valid in Turkey. The findings also imply that environmental quality in Turkey is negatively related to electricity production from renewable energy sources.
Показать больше [+] Меньше [-]Polycyclic Aromatic Hydrocarbons (PAH) in Atmospheric Particles (PM2.5 and PM2.5–10): Integrated Evaluation of the Environmental Scenario in Urban Areas Полный текст
2021
Ceratti, Alessa Maria | da Costa, Gustavo Marques | Alves, Darlan Daniel | Cansi, Laura Meneguzzi | Hansen, Jessica | Brochier, Filipe | de Quevedo, Daniela Müller | Osorio, Daniela Montanari Migliavacca
The 16 United States Environmental Protection Agency (US EPA) priority polycyclic aromatic hydrocarbons (PAHs) are considered carcinogenic and mutagenic for humans and are emitted by anthropogenic sources mainly in urban areas. For this purpose, the carcinogenic risk in the Metropolitan Region of Porto Alegre/RS (RMPA), Brazil, was investigated due to its demographic density (421.8 inhabitants/km²), industrialization, and high flow of vehicles. The concentration of the 16 PAHs present in PM₁₀–₂.₅ and PM₂.₅ was evaluated, and so their origins, the carcinogenic risk of inhalation, and their interaction with meteorological parameters. Dichotomous sampler was used to collect the PM₁₀–₂.₅ and PM₂.₅ in the cities of Canoas (CA) and Novo Hamburgo (NH) in RMPA for having different industries and demographic densities. Extracts containing PAHs were analyzed by gas chromatography coupled to mass spectrometry to determine the concentration of PAHs. Thirteen PAHs were found, mainly in PM₂.₅. The carcinogenic risk was above the US EPA recommended safety range (1 × 10⁻⁶) in PM₂.₅ and PM₂.₅–₁₀ at both NH and CA. Naphthalene obtained the highest concentration, but the presence of benzo[a]pyrene was determinant for the higher carcinogenic risk in PM₂.₅. PAHs in RMPA are emitted mainly from burning by vehicles, increasing concentrations in cold seasons. Due to anthropogenic similarities between CA and NH, the interactions among meteorological parameters and air pollutants were the same. High interaction was observed between PM₂.₅, naphthalene, and meteorological parameters. The integrated evaluation of the factors used by this study shows the relevance of obtaining these data for the prevention of human health.
Показать больше [+] Меньше [-]Separation and characterization of refractory colored dissolved effluent organic matter in a full-scale industrial park wastewater treatment plant Полный текст
2021
Islam, Ashraful | Sun, Guangxi | Shang, Wei | Zheng, Xingcan | Li, Pengfeng | Yang, Min | Zhang, Yu
Colored dissolved organic matter (DOM) is a significant indicator of refractory DOM in wastewaters, and fluorescent DOM is an essential part indicating colorants. However, little is known about the composition and contribution of colored DOM to wastewater. This study provided some insights on the persistent yellowish color in biological effluent through use of a multi-characterization approach, and evaluated the effect of two advanced treatments (O₃ and granular active carbon (GAC)) in a full-scale wastewater treatment plant. The multi-characterization technique incorporated resin fractionation, excitation-emission matrix spectroscopy (EEM) combined with fluorescence regional integration (FRI), size-exclusion chromatography (SEC), and X-ray photoelectron spectroscopy (XPS) analysis. The fractionation results showed that hydrophobic acid (HPOA) and hydrophilic (HPI) substances are abundant in colorants, and HPI-type colorants are comparatively resistant or unable to be removed through GAC and O₃ individually. FRI-based EEMs showed that F₃ (fulvic acid–like organics) and F₅ (humic acid–like organics) mainly account for the yellowish color, and their combined fractions of total colorants are 50%, 31%, and 48% in biological, biological + O₃, and biological + GAC effluents, respectively. SEC for measurement of the apparent molecular weight revealed that these colorants may have molecular weights in the range 2–5 kDa. The XPS analysis indicated that these colorants possess ether or hydroxyl and nitro (C-O/C-N) chromophoric groups with conjugated aromatic structures. For C-O/C-N, O₃ showed good removal efficiency overall. GAC showed exceptionally high efficiency for HPOA but very low efficacy toward HPI-type colorants in terms of C-O/C-N chromophoric functional group removal.
Показать больше [+] Меньше [-]Effect of nanoparticle on rheological properties of surfactant-based nanofluid for effective carbon utilization: capturing and storage prospects Полный текст
2021
Kumar, Ravi Shankar | Goswami, Rishiraj | Chaturvedi, Krishna Raghav | Sharma, Tushar
Previous studies have shown insufficient dispersion and thermal stability of nanofluids for high-temperature carbon capture and storage applications. Compared to the other NPs, TiO₂ nanofluids exhibit superior stability due to their high zeta potential. In previous studies, TiO₂ nanofluids have shown superior performance in heat transfer and cooling applications along with importing the stability of other nanofluids like SiO₂ in form of nanocomposites. Therefore, in this study, a nanofluid formulation consisting of titania nanofluid in a base solution of ethylene glycol (EG) with different co-stabilizers such as surfactants was synthesized for better dispersion stability, enhanced electrical, and rheological properties especially for the use in high-temperature industrial applications which include carbon capture and storage along with enhanced oil recovery. The formulated nanofluid was investigated for stability using dynamic light scattering (DLS) study and electrical conductivity. Additionally, the formulated nanofluid was also examined for thermal stability at high temperatures using an electrical conductivity study followed by rheological measurements at 30 and 90 °C. At a high temperature, the shear-thinning behavior of EG was found highly affected by shear rate; however, this deformation was controlled using TiO₂ nanoparticles (NPs). Furthermore, the role of surfactant was also investigated on dispersion stability, electrical conductivity followed by viscosity results, and it was found that the nanofluid is superior in presence of anionic surfactant sodium dodecyl sulfate (SDS) as compared to nonionic surfactant Triton X-100 (TX-100). The inclusion of ionic surfactant provides a charged layer of micelles surrounding the core of a NP and it produced additional surface potential. Consequently, it increases the repulsive force between two adjacent NPs and renders a greater stability to nanofluid while nonionic surfactant allowed monomers to adsorb on the surface of NP via hydrophobic interaction and enhances the short-range interparticle repulsion, to stabilize nanofluid. This makes titania nanofluid suitable for widespread high-temperature applications where conventional nanofluids face limitations. Finally, the application of the synthesized titania nanofluids was explored for the capture and transport of CO₂ where the inclusion of the anionic surfactant was found to increase the CO₂ capturing ability of titania nanofluids by 140–220% (over the conventional nanofluid) while also showing superior retention at both investigated temperatures. Thus, the study promotes the role of novel surfactant-treated titania nanofluids for carbon removal and storage and recommends their applications involving carbonated fluid injection (CFI) to carbon utilization in oilfield applications.
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