خيارات البحث
النتائج 4201 - 4210 من 7,292
Environmental courts and foreign direct investments: evidence from China النص الكامل
2022
Huang, Xiaoqi | Liu, Wei | Cao, Zhi
As China’s pollution problems worsen, environmental disputes are increasing rapidly. However, only 1% of environmental disputes can be resolved via judicial channels. Based on the establishment of environmental courts since 2007, we employ the multi-period DID approach to investigate the impact of environmental courts on foreign direct investments. We find that (1) compared with cities without environmental courts, FDI of cities with environmental courts would drop by 3.32% from the average, which is consistent with the pollution haven hypothesis. Besides, we verify the credibility of the conclusion through detailed endogeneity discussions, placebo tests, and robustness tests. (2) The negative effect of environmental courts on foreign direct investments is more salient in the east, regions with higher historical environmental investment, and regions with more serious local protectionism. (3) There are two channels. The greater risks of environmental litigation and stricter environmental public supervision brought by environmental courts would lead to additional environmental violation costs, thereby inhibiting foreign direct investments. Our findings provide new causal evidence for the pollution haven hypothesis from the perspective of intensive environmental justice.
اظهر المزيد [+] اقل [-]Diazinon pesticide photocatalytic degradation in aqueous matrices based on reductive agent release in iodide exciting under UV Irradiation النص الكامل
2022
Azarpira, Hossein | Rasolevandi, Tayebeh | Mahvi, Amir Hossein | Karimy, Mahmood
Regarding the cost-effective degradation of diazinon (DIZ), the present study was conducted to develop and UV/iodide process in a photo catalyst reactor. CCD modeling applied and the results shows that the highest R-squared value (adjusted R-squared: 0.9987), the lowest P-value (2.842 e − 10), the lowest AIC (14.54), and the most insignificant lack-of-fit (0.73) belonged to the second-order model. Based on second-order model, the stationary points for time, iodide: DIZ (molar ratio %), DIZ concentration, and pH were 6.99 min, 80.15% iodide: DIZ (molar ratio %), 3.34, mg L⁻¹, and pH 7.34 (− log₁₀[H⁺]), respectively. The maximum reduction efficiency of 97.22% was obtained at the experimental conditions. The LC–MS analyses from optimal condition implied that all the DIZ molecules and its intermediates breaking to simple compounds during 15 min of processing. The data shown UI process reduced the BOD and COD levels by about 66% and 86.29% within 80 min of photoreaction, respectively. Furthermore, in kinetic investigation, with the increase in DIZ concentration, kₒbₛ and rₒbₛ increased and secondly, the conventional and PCBR reactor kₒbₛ increased by about respectively 17% and 50% with an increase in DIZ concentration from 5 to 15 mgL⁻¹. Additionally, when the DIZ concentration increase from 5 to 15 mg L⁻¹, rₒbₛ increased in the conventional and PCBR reactors respectively about 4.9 and 6 times. Figure-of-merit EEₒ changed from 12.66–17.41 to 7.26–10.15 kWhm³ for the conventional reactor, and 8.66–13.61 to 5.24–8.12 kWhm³ in PCBR, when the DIZ concentration increasing from 5 to 15 mg L⁻¹. Consequently, in the PCBR reactor, the energy consumption reduced by 14% at 5 mg L⁻¹ DIZ concentration and by 60% at 15 mg L⁻¹ DIZ concentration. Also, total cost of the system (TCS) decreases from 4.52 to 1.46 $ in conventional reactor and 1.47 to 0.42 $ in PCBR reactor when the DIZ concentration increase from 5 to 15 mg L⁻¹.
اظهر المزيد [+] اقل [-]Effective removal of Sb(V) from aqueous solutions by electrocoagulation with composite scrap iron-manganese as an anode النص الكامل
2022
Zhou, Yongchao | Zheng, Wenxin | Zhang, Wenming | Zhang, Yiping | Fang, Lei
Improving the removal rate of pentavalent antimony (Sb(V)) by electrocoagulation (EC) is of great significance to the environment. In this paper, the EC with composite scrap iron and manganese filings as an anode (Fe–Mn EC) was investigated for the high-efficiency elimination of Sb(V). The results showed that Fe–Mn EC can enhance the removal of Sb(V) by 11.18–17.36% compared with the traditional iron electrocoagulation (Fe EC). Meanwhile, Sb(V) removal increased with the growth of current concentration as well as Mn content in the anode. However, the Sb(V) removal rate was inhibited when Mn content exceeded 20%. Moreover, the flocs generated during the Fe and Fe–Mn EC (Fe flocs and Fe–Mn flocs) were analyzed both structurally and theoretically using XRD, SEM, BET, and adsorption experiment. The results indicated that the components of Fe–Mn flocs were mostly Mn-substituted FeOOH, which appeared as the structure of nanometer flakes and large internal surface areas. Meanwhile, the Fe–Mn flocs had the ability of much faster Sb(V) adsorption rate; its Sb(V) adsorption capacity was 2.5 times more than that of the Fe flocs. The thermodynamics constants of both Fe and Fe–Mn flocs proved that adsorption was associated with monolayer physical adsorption. To the best of our knowledge, this is the first report of the electrocoagulation with composite scrap iron-manganese as an anode to remove Sb, which provide a new idea and potential technical support for the removal of Sb(V).
اظهر المزيد [+] اقل [-]Physalis pubescens L. alleviates testicular disruptions associated with streptozotocin-induced diabetes in male Wistar rats, Rattus norvegicus النص الكامل
2022
Ali, Atef Abdel-Moneem | Essawy, Ehab Abdel-Raouf | Mohamed, Noha Sayed | Abdel Moneim, Ahmed E. | Attaby, Fawzy Ali
Testicular impairment is a serious complication of diabetes that is mediated by oxidative stress and inflammation. Physalis has antioxidative and anti-inflammatory actions. Thus, the present study investigated the ameliorative role of Physalis juice (PJ) prepared from the fruits against testicular damages in streptozotocin (STZ)-induced diabetic rats. Adult male Wistar rats were divided randomly into five groups (n=6): control, orally administered 5 mL PJ/kg daily (PJ), injected intraperitoneally with a single dose of 55 mg STZ/kg without treatment (STZ), or treated daily with PJ (STZ+PJ) or with 500 mg metformin/kg (STZ+Met), for 28 days. The STZ group showed a marked elevation in the blood glucose level by 230%, whereas remarkable declines in the serum levels of testosterone (44%), follicle-stimulating hormone (FSH) (48%), and luteinizing hormone (LH) (36%), as compared to controls. In comparison to controls, the testis of the STZ group showed remarkable declines in the testis weight (15%), the glutathione (GSH) content (45%), mRNA and protein levels of B-cell lymphoma-2 (Bcl-2) (48 and 35%), mRNA and activities of superoxide dismutase (SOD) (63 and 40%), catalase (CAT) (56 and 31%), glutathione peroxidase (GPx) (51 and 44%), and glutathione reductase (GR) (62 and 43%), whereas marked elevations in the levels of interleukin-1 beta (IL-1β (169%), tumor necrosis factor-alfa (TNFα) (85%), nitric oxide (NO) (96%), malondialdehyde (MDA) (83%), mRNA and protein levels of Bcl-2-associated X protein (Bax) (400 and 61%), and mRNA level of caspase-3 (Cas-3) (370%). Some histopathological alterations were observed in the testicular tissue of the STZ group. In contrast, PJ markedly alleviated all the abovementioned disturbances. In conclusion, PJ at a dose of 5 mL/kg attenuated the diabetes-associated testicular impairments, which may be due to its antioxidative, anti-inflammatory, and antiapoptotic actions.
اظهر المزيد [+] اقل [-]Reducing the negative impact of ceftriaxone and doxycycline in aqueous solutions using ferrihydrite/plant-based composites: mechanism pathway النص الكامل
2022
Olusegun, Sunday J. | Mohallem, Nelcy D. S. | Ciminelli, V. S. T.
The adsorption of ceftriaxone (CET) and doxycycline (DOX) from aqueous solution using ferrihydrite/plant-based composites (silica rice husk) to reduce their negative impact on the ecosystem was adequately studied. On the other hand, phosphate and humic acid are often found in water and soil; in view of this, their effects on the adsorption of CET and DOX were investigated. The results showed that the removal of ceftriaxone decreased with an increase in pH, while that of doxycycline did not. Ferrihydrite with 10% silica rice husk (Fh-10%SRH) has the highest maximum adsorption capacity of 139 and 178 mg g⁻¹ for CET and DOX, respectively, at room temperature based on Liu’s adsorption isotherm. This implies that the presence of silica rice husk increases CET and DOX uptake due to an increase in the pore volume of FH-10%SRH. The results showed that phosphate had a significant inhibition role on CET adsorption and minor on DOX, whereas humic acid salt affected neither case. Increase in temperature up to 333 K favored the adsorption of both contaminants. The proposed adsorption mechanisms of ceftriaxone are electrostatic interaction, n-π interaction, and hydrogen bond, while that of DOX entails n-π interaction and hydrogen bond.
اظهر المزيد [+] اقل [-]Assessing the influence of intertropical discontinuity on total column ozone variation over West Africa النص الكامل
2022
Arowolo, Ayomide Victor | Oluleye, Ayodeji
The focus of this study is to evaluate the influence of intertropical discontinuity (ITD) on the variation of total column ozone (TCO). Relevant information is supplied on the temporal and spatial variability of TCO along the ITD zone, which is an important factor influencing the earth’s atmosphere. Several studies over the years have established the relationship and have influence several atmospheric processes on TCO. However, the relationship between intertropical discontinuity and TCO over West Africa has a gap. This study tends to examine the influence ITD has on TCO variation using the West African region as a case study. The study used wind, ozone, and dewpoint temperature data for the period between 1980 and 2019. To assess the variability and trend over the study region, several statistical methods were used, including Pearson correlation, Mann–Kendall, and linear regression model. The Mann–Kendall test shows an increasing trend throughout the months over the study region. Spatial analysis also revealed that regions north of the ITD have a higher concentration of TCO than the southern region of the ITD between April and September. However, ITD influence was more visible during the wet months of June to August (JJA) as the highest concentration of TCO was observed during this period across all latitude, but more deviation was observed between latitude 10 to 18° N, while the least occurrence is observed when ITD is at its minimum position in the month of December to February (DJF). The ACRV shows that 14° N exhibit the highest variation with a value of 4.84, while the deviation is also at its highest with value of 13.65. The monthly position of ITD for 40 years was also analysed to observe the monthly deviation along the ITD region 40 years, and the spatial distribution of TCO was analysed from January to December. It is of note that during the cause of this study, low-ozone values of 220DU are not found in the study region. The highest and the lowest value of TCO is 295 DU and 227 DU, respectively, with an average range of 68DU.
اظهر المزيد [+] اقل [-]Spatial distribution of trace elements in surface sediments of Hooghly (Ganges) river estuary in West Bengal, India النص الكامل
2022
Trifuoggi, Marco | Ferrara, Luciano | Toscanesi, Maria | Mondal, Priyanka | Ponniah, Jonathan Muthuswamy | Sarkar, Santosh Kumar | Arienzo, Michele
The spatial distribution of trace elements in surface sediments of the Hooghly estuary was studied over the monsoons in 2014–2017. As, Cd, Ni, Pb and U were two- to sixteen-fold the crust means with increasing levels toward the estuary, with Ni peak during the post-monsoon. Pearson’s correlation matrix, cluster analysis, enrichment factors and pollution index revealed the anthropic source and association of trace elements with Fe, Mn and Al and of Pb with U. Geoaccumulation index revealed for Ni an extremely contaminated situation at the estuary water during monsoon and for Cd a heavily contaminated situation at freshwater location. The potential contamination index was >6; thus, sediments were very severely contaminated by As, Cd and Ni with worst situation for As and Cd at fresh and brackish water and during post-monsoon. The overall ecological risk was severe, 300≤RI<600 at all sites and seasons, especially after the monsoon, at fluvial and brackish locations.
اظهر المزيد [+] اقل [-]Impacts of horseradish peroxidase immobilization onto functionalized superparamagnetic iron oxide nanoparticles as a biocatalyst for dye degradation النص الكامل
2022
Keshta, Basem E. | Gemeay, Ali H. | Khamis, Abeer A.
To enhance the dye removal efficiency by natural enzyme, horseradish peroxidase (HRP) was immobilized onto amine-functionalized superparamagnetic iron oxide and used as a biocatalyst for the oxidative degradation of acid black-HC dye. The anchored enzyme was characterized by vibrating sample magnetometry, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetry, scanning electron microscopy, Brunauer–Emmett–Teller and Barrett–Joyner–Halenda methods, nitrogen adsorption–desorption measurements, Zeta potential, energy dispersive X-ray spectroscopy, and transmission electron microscopy. The Michaelis constant values of free and immobilized HRP were determined to be 4.5 and 5 mM for hydrogen peroxide and 12.5 and 10 mM for guaiacol, respectively. Moreover, the maximum values of free and immobilized HRP were 2.4 and 2 U for H₂O₂, respectively, and 1.25 U for guaiacol. The immobilized enzyme was thermally stable up to 60°C, whereas the free peroxidase was stable only up to 40°C. In the catalytic experiment, the immobilized HRP exhibited superior catalytic activity compared with that of free HRP for the oxidative decolorization and removal of acid black-HC dye. The influence of experimental parameters such as the catalyst dosage, pH, H₂O₂ concentration, and temperature on the removal efficiency was investigated. The reaction followed second-order kinetics, and the thermodynamic activation parameters were determined.
اظهر المزيد [+] اقل [-]Ectomycorrhizal fungi enhance the tolerance of phytotoxicity and cadmium accumulation in oak (Quercus acutissima Carruth.) seedlings: modulation of growth properties and the antioxidant defense responses النص الكامل
2022
Sun, Wen | Yang, Baoshan | Zhu, Yidan | Wang, Hui | Qin, Guanghua | Yang, Hanqi
Ectomycorrhizal fungi (EMF), which form symbiotic ectomycorrhiza with tree roots, mediate heavy metal tolerance of host plants. To investigate the roles of EMF in the growth, modulation of oxidative stress, and cadmium (Cd) accumulation and translocation in Quercus acutissima seedlings, ectomycorrhizal seedlings inoculated with Suillus luteus were treated with different Cd concentrations (0.1, and 5 mg kg⁻¹) for 14 days. EMF accelerated seedling growth and Cd accumulation in roots under the highest Cd concentration of 5 mg kg⁻¹. Catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) activities increased in the leaves of ectomycorrhizal seedlings under the highest Cd concentration. Superoxide dismutase (SOD) trended to increase under both Cd concentrations. Although reduced glutathione (GSH) increased after inoculation of EMF under both Cd concentrations, the release of malondialdehyde increased in the leaves and roots under the highest Cd concentration, indicating that the defense role of EMF in Q. acutissima depends on the Cd concentration. These results indicate that EMF mitigate Cd stress by promoting plant growth and nutrient uptake while modulating the antioxidant system to reduce oxidative stress.
اظهر المزيد [+] اقل [-]Removal of Hydrocarbons from Wastewater Using Sugarcane Bagasse النص الكامل
2022
de la Concepción Martínez-Nodal, Pastora | Rodríguez-Rico, Iván Leandro | Domínguez, Elena Rosa | Rodríguez-Machín, Lizet
The presence of hydrocarbons in wastewater causes innumerable problems for ecosystems and is a pollution problem that needs to be solved. This paper shows the results obtained in the removal of hydrocarbons (diesel) using natural sugar cane bagasse (BN). Thermodynamic and kinetic studies of the biosorption process were carried out at two temperatures: 25 °C and 35 °C and studies in a column packed with (BN) at granulometry (+1–2 mm). The results obtained in the equilibrium and sorption studies were adjusted using the Langmuir and Freundlich sorption isotherm models. The thermodynamic parameters show a predominance of a physical sorption; in a process is exothermic and spontaneous. The pseudo second-order model better fits the kinetics of hydrocarbon biosorption with natural bagasse (R² ≥ 0.98). The rupture curve where the point is reached at 6 h of operation was obtained experimentally. Scanning electron microscopy studies coupled to EDX of depleted BN show that it undergoes changes in its structure, showing a degree of surface dismemberment. The increase in the C/O ratio shows the presence of hydrocarbons that were adsorbed. In the thermogravimetric study, the anaerobic pyrolysis stage of cellulose (200 °C and 400 °C) decreases energetically and the loss of mass is less; this behavior is associated with the adsorbed hydrocarbon (diesel). The results obtained showed that BN has potential as a hydrocarbon biosorbent, with removals of 60.3% of total hydrocarbons (HCT) present in real wastewater, coming from a Power Plant that operates with diesel.
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