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Environmental pollution and energy research and development: an Environmental Kuznets Curve model through quantile simulation approach Texte intégral
2021
Bilgili, Faik | Nathaniel, Solomon Prince | Kuşkaya, Sevda | Kassouri, Yacouba
Energy research and development (R&D) and environmental sustainability is often referred to as two interrelated trends, especially in the current context of the 4ᵗʰ industrial revolution. As a primary input of energy innovations, R&D in the energy sector constitutes a vital tool in addressing global environmental and energy challenges. In this frame, we observe the effects of disaggregated energy R&D on environmental pollution within the Environmental Kuznets Curve (EKC) framework in thirteen developed countries over the period 2003–2018. By employing the panel quantile regression technique, we find an inverted U-shaped nexus between economic growth and carbon emissions only in higher carbon-emitting countries, thus, confirming the EKC hypothesis. However, the U-shaped nexus is more predominant in lower carbon-emitting countries. As such, we demonstrate that there is not any single dynamic in the relationship between economic growth and pollution as reported in previous studies. Contrary to expectations, we find that energy efficiency research and development is more effective in curbing carbon emissions compared to fossil fuels and renewable energy research and development. The empirical results indicate also that only energy efficiency R&D mitigates significantly the CO₂ emissions from the 50ᵗʰ quantile up to 90ᵗʰ quantile, although the magnitude of the negative sign is more pronounced (in absolute term) at the highest quantile (90th). In this light, our findings would guide policymakers in the establishment of sustainable energy research and development schemes that will allow the preservation of equilibrium for the environment while also promoting energy innovations.
Afficher plus [+] Moins [-]Reclaimed water driven lettuce cultivation in a hydroponic system: the need of micropollutant removal by advanced wastewater treatment Texte intégral
2021
Kreuzig, Robert | Haller-Jans, Jaqueline | Bischoff, Cornelia | Leppin, Johannes | Germer, Jörn | Mohr, Marius | Bliedung, Alexa | Dockhorn, Thomas
For a novel approach of resource-efficient water reuse, a municipal wastewater treatment plant was extended at pilot scale for advanced wastewater treatment, i.e., ozonation and biological activated carbon filtration, and a hydroponic system for reclaimed water driven lettuce cultivation. The treatment specific wastewater lines with the corresponding lettuce plants, differentiated into roots and shoots, were monitored for priority wastewater micropollutants, i.e., acesulfame (sweetener), caffeine (stimulant), carbamazepine, diclofenac, ibuprofen, sulfamethoxazole with acetyl-sulfamethoxazole (human pharmaceuticals), 1H-benzotriazole, and 4/5-methylbenzotriazole (industrial chemicals). As clearly demonstrated, conventional tertiary treatment could not efficiently clean up wastewater. Removal efficiencies ranged from 3% for carbamazepine to 100% for ibuprofen. The resulting pollution of the hydroponic water lines led to the accumulation of acesulfame, carbamazepine, and diclofenac in lettuce root systems at 32.0, 69.5, and 135 μg kg⁻¹ and in the uptake of acesulfame and carbamazepine into lettuce shoots at 23.4 and 120 μg kg⁻¹ dry weight, respectively. In contrast, both advanced treatment technologies when operating under optimized conditions achieved removal efficiencies of > 90% also for persistent micropollutants. Minimizing the pollution of reclaimed water thus met one relevant need for hydroponic lettuce cultivation.
Afficher plus [+] Moins [-]Long-term effects of liquid swine manure land surface application in an apple orchard field on soil bacterial community and heavy metal contents in apple (Malus pumila Mill.) Texte intégral
2021
Jiao, Hongchao | Yin, Qin | Fan, Cunhu | Wang, Ling | Zhao, Jingpeng | Wang, Xiaojuan | Du, Kun | Lin, Hai
This study investigated the impact of liquid swine manure (LSM) land surface application in an apple orchard on soil health and copper (Cu) and zinc (Zn) in soil and apple. Three apple plots were selected, among which two for LSM application for 5 (AY5) and 11 (AY11) years with different application rates, a long-term inorganic fertilizer application plot as the control treatment (AY0). The soil and apple samples were collected for analysis of soil physicochemical properties, bacterial diversity and abundance, and the contents of Cu and Zn in soil and apple. Results showed that the LSM application significantly increased the concentration of soil nutrients with the highest in AY5, which has a high application rate of LSM. After 5 or 11 years applied, the content of total nitrogen (TN) in AY5 and AY11 increased by 125.2% and 96.7%, total phosphorus (TP) increased by 167.6% and 148.6%, and soil organic matter (SOM) increased by 180.7% and 120.6%, respectively. The AY5 treatment significantly lowered OTUs and decreased Shannon index trend with a negative correlation between soil organic matter and Shannon index. The six predominant bacterial phyla in different treatments were similar, but the LSM application significantly increased the abundance of Chloroflexi and Firmicutes. However, the abundance of Actinobacteria and Acidobacteria significantly decreased in AY5 as compared to control treatment, followed by a significant positive correlation between the abundance of Acidobacteria and soil pH. Besides, LSM application significantly increased the contents of soil Cu, Zn, and apple Zn. Overall, the results illustrated that appropriate application rate of LSM can effectively improve apple orchard soil quality and bacterial community structure, but it will increase the risk of heavy metal accumulation in soil and apples.
Afficher plus [+] Moins [-]Role of multidrug resistance-associated proteins in cancer therapeutics: past, present, and future perspectives Texte intégral
2021
Elfadadny, Ahmed | El-Husseiny, Hussein M. | Abugomaa, Amira | Ragab, Rokaia F. | Mady, Eman A. | Aboubakr, Mohamed | Samir, Haney | Mandour, Ahmed S. | El-Mleeh, Amany | El-Far, Ali H. | Abd El-Aziz, Ayman H. | Elbadawy, Mohamed
Cancer, a major public health problem, is one of the world’s top leading causes of death. Common treatments for cancer include cytotoxic chemotherapy, surgery, targeted drugs, endocrine therapy, and immunotherapy. However, despite the outstanding achievements in cancer therapies during the last years, resistance to conventional chemotherapeutic agents and new targeted drugs is still the major challenge. In the present review, we explain the different mechanisms involved in cancer therapy and the detailed outlines of cancer drug resistance regarding multidrug resistance-associated proteins (MRPs) and their role in treatment failures by common chemotherapeutic agents. Further, different modulators of MRPs are presented. Finally, we outlined the models used to analyze MRP transporters and proposed a future impact that may set up a base or pave the way for many researchers to investigate the cancer MRP further.
Afficher plus [+] Moins [-]Enhanced adsorption capacity of tetracycline on tea waste biochar with KHCO3 activation from aqueous solution Texte intégral
2021
Li, Bin | Huang, Yingying | Wang, Zixin | Li, Jiale | Liu, Zhuo | Fan, Shisuo
Activation is an important pathway that can enhance the adsorption capacity of biochar. In this study, a modified tea waste biochar (MTWBC) was prepared via a two-step pyrolysis approach with KHCO₃ activation. Pristine tea waste biochar (TWBC) was also produced as control via one-step pyrolysis without activation. Various characterizations were undertaken to investigate the influence of modification on the morphology, composition, carbon structure, surface area, and functional group of biochar, including scanning electron microscope (SEM), surface area and pore analyzer, element analysis, point of zero charge (pHPZC), X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). After KHCO₃ activation treatment, the surface area, total pore volume, and micropore volume of MTWBC reached 1981 m²·g⁻¹, 0.8547 cm³·g⁻¹, and 0.6439 cm³·g⁻¹ which were 7.34-fold, 7.27-fold, and 7.30-fold increases, respectively, compared with TWBC. The aromaticity, hydrophilicity, and polarity of the MTWBC increased after modification. More graphitization with less defective structures occurred in MTWBC after modification. The C-, O-, and N-containing groups in MTWBC also changed after the reaction of KHCO₃. The pseudo-second-order and Freundlich models best described the adsorption process on biochar. The maximum adsorption capacity of tetracycline (TC) on MTWBC reached 293.46 mg·g⁻¹, which was 15-fold more than that of TWBC (19.68 mg·g⁻¹). An alkaline environment decreased the TC adsorption on biochars. The presence of Na⁺, K⁺, Ca²⁺, and Mg²⁺ inhibited TC adsorption onto biochars. The influence of Cu²⁺ on TC adsorption by biochars depends on its initial concentration. The enhanced adsorption capacity of TC on MTWBC was mainly attributable to the large surface area, the improved pore volume, and more aromatic structure. The adsorption mechanism was based on pore filling and π-π EDA interaction. Therefore, KHCO₃ activated biochar has the potential to remove TC from aquatic environments.
Afficher plus [+] Moins [-]Nitrogen process in stormwater bioretention: the impact of alternate drying and rewetting on nitrogen migration and transformation Texte intégral
2021
Chen, Yao | Chen, Renyu | Liu, Zhen | Yu, Xuehua | Zheng, Shuang | Yuan, Shaochun
Nitrogen migration and transformation in the stormwater bioretention system were studied in laboratory experiments, in which the effects of drying-rewetting were particularly investigated. The occurrence and distribution of nitrogen in the plants, the soil, and the pore water were explored under different drying-rewetting cycles. The results clearly showed that bioretention system could remove nitrogen efficiently in all drying-rewetting cycles. The incoming nitrogen could be retained in the topsoil (0–10 cm) and accumulated in the planted layer. However, the overlong dry periods (12 and 22 days) cause an increase in nitrate in the pore water. In addition, nitrogen is mostly stored in the plants’ stem tissues. Up to 23.26% of the inflowing nitrogen can be immobilized in plant tissues after a dry period of 22 days. In addition, the relationships between nitrogen reductase activity in the soil and soil nitrogen content were explored. The increase of soil TN content could enhance the activity of nitrate reductase. Meanwhile, the activity of hydroxylamine reductase (HyR) could be enhanced with the increase of soil NO₃⁻ content. These results provide a reference for the future development of nitrogen transformation mechanism and the construction of stormwater bioretention systems.
Afficher plus [+] Moins [-]Biocatalyst physiology and interplay: a protagonist of MFC operation Texte intégral
2021
Mukherjee, Priya | Pichiah, Saravanan | Packirisamy, Gopinath | Jang, Min
Microbial fuel cells (MFC) have been foreseen as a sustainable renewable energy resource to meet future energy demand. In the past, several studies have been executed in both benchtop and pilot scale to produce electrical energy from wastewater. The key role players in this technology that leads to the operation are microbes, mainly bacteria. The dominant among them is termed as “exoelectrogens” that have the capability to produce and transport electron by utilizing waste source. The current review focuses on such electrogenic bacteria’s involvement for enhanced power generation of MFC. The pathway of electron transfer in their cell along and its conduction to the extracellular environment of the MFC system are critically discussed. The interaction of the microbes in various MFC operational conditions, including the role of substrate and solid electron acceptors, i.e., anode, external resistance, temperature, and pH, was also discussed in depth along with biotechnological advancement and future research perspective.
Afficher plus [+] Moins [-]Growth and determinants of CO2 emissions: evidence from selected Asian emerging economies Texte intégral
2021
Mujtaba, Aqib | Jena, Pabitra Kumar | Joshi, Debanam Priyam Priyadarshi
The study analyzes the impact of economic growth, energy consumption, foreign direct investment inflows, population, population density, labor force, and trade openness on carbon dioxide emissions in seven emerging Asian economies over the period 1991–2017. To this end, it uses cross-section dependence test, second-generation unit root test, panel cointegration, and the bound test for cointegration and the autoregressive distributed lag estimations. The findings of the study are as follows: first, the kinked exponential growth is estimated for all the variables on the individual data set of seven countries. Second, the study finds a positive association of economic growth, energy consumption, population, and population density on carbon dioxide emissions. Third, it finds that the foreign direct investment inflows are negatively associated with carbon dioxide emissions. The paper also suggests potential implications and some future research avenues.
Afficher plus [+] Moins [-]Geopolitical risks, energy consumption, and CO2 emissions in BRICS: an asymmetric analysis Texte intégral
2021
Zhao, Weijun | Zhong, Ruoyu | Sohail, Sidra | Majeed, Muhammad Tariq | Ullah, Sana
Environmental pollution is a geopolitical problem, and researchers have not considered it seriously yet. This study examines the asymmetric influence of geopolitical risk on energy consumption and CO₂ emissions in BRICS economies using the non-linear autoregressive distributed lag model (NARDL) testing method over the period of 1985–2019. Therefore, we observed that in the long run, a positive and negative change in geopolitical risk has negative effect on energy consumption in India, Brazil, and China. The outcomes confirmed that an increase in geopolitical risk has negative effect on CO₂ emissions in Russia and South Africa. Although a decrease in geopolitical risk has negative effects on CO₂ emissions in India, China, South Africa, it has positive coefficient in Russia in the long run. Based on empirical findings, we also revealed that asymmetries mostly exist in terms of magnitude rather than direction. Our empirical results are country and group specific. The findings call for important changes in energy and environment policies to accommodate geopolitical risks.
Afficher plus [+] Moins [-]Genomic markers for the biological responses of Triclosan stressed hatchlings of Labeo rohita Texte intégral
2021
Sharma, Sunil | Dar, Owias Iqbal | Kirpal Singh, | Ṭhākara, Śarada | Kesavan, Anup Kumar | Arawindara Kaura,
Triclosan (TCS) used commonly in pharmaceuticals and personal care products has become the most common pollutant in water. Three-day-old hatchlings of an indigenous fish, Labeo rohita, were given 96h exposure to a nonlethal (60 μg L⁻¹) and two moderately lethal concentrations (67 and 97 μg L⁻¹) of TCS and kept for 10 days of recovery for recording transcriptomic alterations in antioxidant/detoxification (SOD, GST, CAT, GPx, GR, CYP1a and CYP3a), metabolic (LDH, ALT and AST) and neurological (AchE) genes and DNA damage. The data were subjected to principal component analysis (PCA) for obtaining biomarkers for the toxicity of TCS. Hatchlings were highly sensitive to TCS (96h LC₅₀ = 126 μg L⁻¹ and risk quotient = 40.95), 96h exposure caused significant induction of CYP3a, AChE and ALT but suppression of all other genes. However, expression of all the genes increased significantly (except for a significant decline in ALT) after recovery. Concentration-dependent increase was also observed in DNA damage [Tail Length (TL), Tail Moment (TM), Olive Tail Moment (OTM) and Percent Tail DNA (TDNA)] after 96 h. The damage declined significantly over 96h values at 60 and 67 μg L⁻¹ after recovery, but was still several times more than control. TCS elicited genomic alterations resulted in 5–11% mortality of exposed hatchlings during the recovery period. It is evident that hatchlings of L. rohita are a potential model and PCA shows that OTM, TL, TM, TDNA, SOD and GR (association with PC1 during exposure and recovery) are the biomarkers for the toxicity of TCS. Graphical abstract
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