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Morphological, molecular, and biochemical study of cyanobacteria from a eutrophic Algerian reservoir (Cheffia) 全文
2022
Benredjem, Lamia | Berredjem, Hajira | Abdi, Akila | Casero, Maria Cristina | Quesada, Antonio | Fosso, Bruno | Marzano, Marinella | Pesole, Graziano | Azevedo, Joana | Vasconcelos, Vitor
The cyanobacteria management in water bodies requires a deep knowledge of the community composition. Considering the reliable and thorough information provided by the polyphasic approach in cyanobacteria taxonomy, here we assess the cyanobacterial community structure of the Cheffia reservoir from Algeria. Cyanobacteria were identified on the basis of morphological traits and next-generation sequencing (NGS); toxins-related genes were localized in addition to the identification of toxins; temperature and nutrient level of water samples were also determined. The polyphasic approach was essential for cyanobacteria investigation; 28 genera were identified through 16S rRNA metabarcoding with the dominance of taxa from Microcystis (34.2%), Aphanizomenon (20.1%), and Planktothrix (20.0%), and morphological analysis revealed the association in this water body of five species within the genus Microcystis: M. aeruginosa, M. novacekii, M. panniformis, M. ichthyoblabe, and M. flos-aquae. The presence of mcyE genotypes was detected; moreover, HPLC–PDA and LC–ESI–MS/MS revealed the production of microcystin-LR. Results obtained in our study are very important since this ecosystem is used for water supply and irrigation; as a consequence, a good water management plan is essential.
显示更多 [+] 显示较少 [-]Reuse of lead glass sludge in the fabrication of thermally insulating foamed glass with outstanding properties and high Pb-stabilization 全文
2022
Abdel-Gawwad, Hamdy A. | Mohammed, Mona S. | Arif, Mohammed A. | Shoukry, Hamada
This study represents the sustainable/safe consumption of lead glass sludge (LGS) in the fabrication of thermally insulating foamed glass via sintering (750–950º C) and chlorination processes. The impact of selected additives including calcium chloride (CaCl₂) and sodium hydroxide (NaOH) on the foaming efficiency and Pb-stabilization has been deeply investigated. LGS is mainly lead silicate material with considerable content of calcium carbonate, which acts as foaming agent during sintering process. The newly developed foamed-materials exhibited thermal conductivity of 0.054–0.136 W/m.K, density of 0.23–1.10 g/cm³, porosity of 63.3–92.6%, and compressive strength of 0.10–2.69 MPa. X-ray diffraction proved that the immobilization mechanism was attributed to the transformation of free Pb within LGS into insoluble ganomalite Pb₉Ca₅MnSi₉O₃₃ phase. Adding NaOH enhanced the foaming process accompanied by a significant reduction in Pb-leaching. Incorporating CaCl₂ has resulted in a retardation in Pb-leaching, which associated with Pb-stabilization and Pb-vaporization. In an attempt to reduce CO₂-emission, the potential use of alkali-rich-wastewater (AW) as eco-friendly alkali source in lieu of NaOH was studied. Regardless of the variation in Pb-concentrations in leachates, all samples recorded Pb-concentrations lower than the safe limit (≤ 5 mg/l), achieving Pb-immobilization of 95.98–99.87%. The significantly reduced thermal conductivity and enhanced Pb-immobilization efficiency along with the reasonable compressive strength summarize the major innovation presented in this study.
显示更多 [+] 显示较少 [-]Multi-template molecularly imprinted polymer hybrid nanoparticles for selective analysis of nonsteroidal anti-inflammatory drugs and analgesics in biological and pharmaceutical samples 全文
2022
Vahidifar, Mohammad | Es’haghi, Zarrin | Oghaz, Nader Mansoori | Mohammadi, Ali Akbar | Kazemi, Malihe Samadi
The multi-template molecularly imprinted polymers reinforced with hybrid oxide nanoparticles were developed for the selective separation and determination of the trace level of naproxen (NPX), methocarbamol (MTH), and omeprazole (OMZ) simultaneously from biological and pharmaceutical samples. The polymers were constructed by magnetic core@shell molecularly imprinted polymer nanocomposite (Fe₃O₄/ZnO/CuO/MWCNT@MIP). An electrochemical sensor has been fabricated for this purpose. Fe₃O₄/ZnO/CuO/MWCNT nanocomposite was introduced to improve the electron transport capability and increase the sensor surface area, as well as enhance the electronic conductivity. The triple-template MIP-coated layer provides simultaneous selective identification of three analytes by using [Fe (CN)₆]³⁻/⁴⁻as the redox probe. Electrochemical behavior of MTH, NPX, and OMZ on the modified electrode (Fe₃O₄/ZnO/CuO/MWCNT@MIP) by various techniques such as cyclic voltammetry, differential pulse voltammetry, and chronoamperometry was examined. The morphology of the modified and unmodified carbon paste electrodes was performed by scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD). The average crystal size for fabricated nanoparticles obtained by calculating the X-ray diffraction technique was 17 nm in the Scherer method. The particle size which was determined by SEM was 48 nm. Some electrochemical parameters such as the diffusion coefficient and electron transfer coefficient were determined. The effect of many variables such as the pH and scan rate was also investigated. Under optimal conditions, the sensor is designed in the linear range 5.0 nM-100 μM and 5.0 nM-100 μM and 1.0 nM-130 μM with a detection limit of 1.5 nM, 1.0 nM, and 0.7 nM for measurement OMZ, NPX, and MTH, respectively. The relative standard deviation (RSD) of the five measurements was 1.21%, 2.23%, and 2.56% for NPX, MTH, and OMZ. Finally, the designed sensor was successfully used for simultaneous detection of target analytes in the real samples; tablets, water samples, and biological samples.
显示更多 [+] 显示较少 [-]Managing e-waste from a closed-loop lifecycle perspective: China’s challenges and fund policy redesign 全文
2022
Tian, Tingting | Liu, Guangfu | Yasemi, Hussein | Liu, Yang
E-waste is one of the fastest growing streams of solid waste globally, and its effective management has become a focused issue, which requires a deep understanding of the core guiding theory of extended producer responsibility (EPR). Over the past 20 years, China, one of the world’s largest producers of electrical and electronic equipment (EEE), has made great efforts to improve e-waste management along with the massive generation of e-waste. In 2012, China implemented a unique EPR-based e-waste fund policy. However, the fund policy is unsustainable due to the challenges of non-closed resource use, informal recycling, and fund imbalance. Beginning with an overview of these challenges, this paper focuses on redesigning the fund policy from a closed-loop lifecycle perspective in order to maintain a balanced development of the resource use loop and the fund system in China’s ten-year plan. In doing so, two EPR instruments, recycling content standards and consumer-oriented deposits, are added to the current fund policy. Subsequently, three extension scenarios alternately changed a critical parameter of the model to test the impact on sustainable capabilities. In this way, the sustainable supply of funds and secondary resources for the e-waste industry can be established in China and effectively demonstrate solid waste management in developing countries.
显示更多 [+] 显示较少 [-]Spatiotemporal evolution characteristics of urbanization and its coupling coordination degree in Russia — perspectives from the population, economy, society, and eco-environment 全文
2022
Chu, Nanchen | Zhang, Pingyu | Wu, Xiangli
Under the background of “the Belt and Road” and “the economic corridor of China, Mongolia and Russia” initiatives, it is of great significance to study the temporal and spatial evolution characteristics of urbanization in Russia. This paper studied the population urbanization level, economic urbanization level, social urbanization level, eco-environment urbanization level, and their coupling coordination development degree during 2005–2020 in Russia. First, combining with the Population-Economic-Sociology-Eco-environment model, the paper constructed the index systems to evaluate the urbanization development levels in Russia. Second, based on the comprehensive weighting method of entropy weight and variation coefficient, this paper calculated the population urbanization level, economic urbanization level, social urbanization level, and eco-environment urbanization level in Russia. Third, this paper used the coupling coordination model to measure the coupling coordination degree of the urbanization development levels in Russia. Finally, the spatial differentiation of the population urbanization level, economic urbanization level, social urbanization level, eco-environment urbanization level, and their coupling coupling-coordination degree was performed, respectively, by using ArcGIS. The results are as the following. First, from 2005 to 2020, the economic urbanization level and eco-urbanization level have shown the increasing trend in Russia. The population urbanization level and social urbanization level have shown the stable changing trend in Russia. The eco-environment urbanization and economic urbanization contribute larger share to the urbanization system compared with the population urbanization and social urbanization. The coupling coordination development degree of population urbanization level, economic urbanization level, social urbanization level, and eco-environment urbanization level has showed a slight increasing trend. However, the overall situation of the urbanization in Russia is still in the moderate uncoordinated recession stage. Second, the federal subjects with high urbanization development levels are mainly distributed in Moscow city, Moscow Region, Sverdlovsk Region, Tumen Region, Saint-Petersburg city, Republic of Tatarstan, Krasnoyarsk Territory, Republic of Bashkortostan, Chelyabinsk Region, Nizhny Novgorod Region, Krasnodar Territory, Rostov Region, and Khanty-Mansiysky Autonomous Area. The federal subjects with low ones are mainly located in Republic of Khakasia, Republic of Marii El, Republic of Kabardino-Balkaria, Republic of Tyva, Republic of Karachaevo-Cherkessia, Republic of Kalmykia, Republic of Altay, Jewish Autonomous Area, and Republic of Ingushetia. Third, spatially, from 2005 to 2020, the urbanization pattern of population, economy, society, eco-environment, and their coupling coordination degree in Russia all show unbalanced development characteristics. The population urbanization pattern and the social urbanization pattern have not changed significantly, showing the spatial characteristics of “high west, low east,” and “high middle, low north, low south.” The economic urbanization pattern has been increasing significantly, showing the spatial characteristics of “high core, low edge.” The eco-environment urbanization pattern has not changed significantly, showing the spatial characteristics of “high north, low south.” The coupling coordinated development degree of urbanization pattern has showed a slight increasing trend, showing the spatial characteristics of “high middle, low north, low south,” “high west, low east”. Finally, we suggest policies and strategies that can boost the growth and development of the urbanization in Russia.
显示更多 [+] 显示较少 [-]Fabrication of glutathione functionalized self-assembled magnetite nanochains for effective removal of crystal violet and phenol red dye from aqueous matrix 全文
2022
Behera, Monalisha | Kumari, Nisha | Raza, Kaisar | Singh, Ritu
A novel fabrication of magnetite (Fe₃O₄) nanochains, surface functionalized with glutathione (GSH), has been attempted through a basic wet reduction method, coalesced with oxidative etching for the removal of crystal violet (CV) and phenol red (PR) from an aqueous solution. The structural and functional characterizations of GSH@Fe₃O₄ MNPs were performed using SEM-EDX, DLS, XRD, and FTIR. The nanochain-structured adsorbent was found to have an average size of 24 ± 1.29 nm and a zeta potential value of − 6.44 mV. The batch experiments showed that GSH@Fe₃O₄ MNPs have a brilliant removal efficiency of 97% and 79% for CV and PR dyes, respectively, within a period of 60 min. The influence of different operational parameters like adsorbent dosage, pH, temperature, reaction time, and initial dye concentration on the removal behaviour of the adsorbent was studied in detail. The adsorbate-adsorbent reaction was tested over isotherm models, and the reaction fitted well for Langmuir isotherm with an excellent qₘₐₓ value of 1619.5 mg/g and 1316.16 mg/g for CV and PR dye, respectively. The experimental results were also validated using different reaction kinetics, and it was found that the pseudo-first-order model fits well for PR dye adsorption (R² = 0.91), while adsorption of CV dye was in best agreement with the pseudo-second-order kinetic model (R² = 0.98). Thermodynamic studies revealed that the adsorption reaction was spontaneous and endothermic in nature. Furthermore, GSH@Fe₃O₄ MNPs can be reused effectively up to 5 cycles of dye removal. Major mechanisms involved in the adsorption reaction were expected to be electrostatic attraction, hydrogen bonding, and π-interactions. The efficiency of GSH@Fe₃O₄ MNPs in real water samples suggested that it has a high potential for dye removal from complex aqueous systems and could be used as an effective alternative for remediation of dyes contaminated water.
显示更多 [+] 显示较少 [-]Phytoextraction, accumulation, and toxicological effects of 1-tetradecyl-3-methylimidazolium ionic liquid in ryegrass (Lolium perenne L.) 全文
2022
Yilimulati, Mihebai | Du, Hong | Wu, Wei | Habibul, Nuzahat
Ionic liquids are widely used in many fields due to their extremely tunable nature and exceptional properties. The extensive application of ionic liquids raises great concerns regarding their bioaccumulation potential and adverse effects on organisms. Green plants have a great potential for uptake of persistent xenobiotics from aquatic and terrestrial environment. However, the assimilation and bioaccumulation of 1-tetradecyl-3-methylimidazolium bromide ([C₁₄mim]Br) have not been studied in plants yet. In order to explore the phytoaccumulation of [C₁₄mim]⁺, ryegrass were exposed to [C₁₄mim]Br with hydroponic experiment. The effects of [C₁₄mim]Br dosages on growth index, chlorophyll content, malondialdehyde (MDA) content, and antioxidant enzyme activity of ryegrass were investigated. The toxic effects of [C₁₄mim]Br on ryegrass growth increased with increasing initial concentration. The high initial concentration treatment resulted in rapid changes in physiological characteristics in ryegrass tissue. [C₁₄mim]⁺ ions were mainly accumulated in root tissue and partly translocated to the above ground part of ryegrass. [C₁₄mim]⁺ was observed in the highest concentration (314.35 μg/g in root and 101.42 μg/g in aboveground parts of ryegrass) with 10 mg/L of [C₁₄mim]Br. Our results demonstrated that ryegrass can uptake and accumulate [C₁₄mim]⁺ and is therefore a suitable species for phytoremediation of trace amount of [C₁₄mim]⁺ and possibly other ionic liquids.
显示更多 [+] 显示较少 [-]Does agricultural cooperative membership help reduce the overuse of chemical fertilizers and pesticides? Evidence from rural China 全文
2022
Liu, Tongshan | Wu, Gang
The overuse of chemical fertilizers and pesticides (CFPs) has negatively impacted the environment and human health. It is an urgent issue that should be addressed. In this study, we investigate whether agricultural cooperatives can serve as an institutional arrangement that helps reduce the consumption of CFPs, using the data of 2012 family farms from the Ministry of Agriculture and Rural Affairs of China. Various approaches, including instrumental variable-based two-stage residual inclusion approach (2SRI), endogenous switching probit (ESP) model, and endogenous switching regression (ESR) model, are utilized to help address the endogeneity issues of the cooperative membership variable. The results show that agricultural cooperative membership significantly increases the probability of reducing fertilizers and pesticides of the family farms and improves net return per yuan CFPs. The further analysis shows that agricultural cooperative production services reduced the usage of fertilizers and pesticides, while cooperatives marketing services only significantly lowered the use of pesticides. Our findings highlight the importance of promoting the development of agricultural cooperatives to support green agricultural production in China.
显示更多 [+] 显示较少 [-]Assessment of potential benefits of traffic and urban mobility reductions during COVID-19 lockdowns: dose-response calculations for material corrosions on built cultural heritage 全文
2022
Broomandi, Parya | Tleuken, Aidana | Zhaxylykov, Shaikhislam | Nikfal, Amirhossein | Kim, Jong Ryeol | Karaca, Ferhat
Air pollution, particularly in urban areas, puts human health in danger and has adverse impacts on the built environment. It can accelerate the natural corrosion rate of cultural heritages and monuments, leading to premature aging and lowering their aesthetic value. Globally, at the beginning of 2020, to tackle the spread of novel COVID-19, the lockdown was enforced in the most hard-hit countries. Therefore, this study assesses, as a first time, the plausible benefits of traffic and urban mobility reductions on the natural process of deterioration of materials during COVID-19 lockdown in twenty-four major cities on five continents. The potential risk is estimated based on exceeding the tolerable degradation limits for each material. The notable impact of COVID-19 mobility restrictions on air quality was evidenced in 2020 compared to 2019. The introduced mobility restrictions in 2020 could decrease the surface recession rate of materials. Extremely randomized trees analysis showed that PM₁₀ was the main influencing factor for corrosion of portland, copper, cast bronze, and carbon steel with a relative importance of 0.60, 0.32, 0.90, and 0.64, respectively, while SO₂ and HNO₃ were mainly responsible for corrosion of sandstone and zinc with a relative importance of 0.60 and 0.40, respectively. The globally adverse governed meteorological conditions in 2020 could not positively influence the movement restrictions around the world in air quality improvements. Our findings can highlight the need for additional policies and measures for reducing ambient pollution in cities and the proximity of sensitive cultural heritage to avoid further damage.
显示更多 [+] 显示较少 [-]Bioactivity and safety evaluations of Cupressus sempervirens essential oil, its nanoemulsion and main terpenes against Culex quinquefasciatus Say 全文
2022
Almadiy, Abdulrhman A. | Nenaah, Gomah E.
The essential oil (EO) of Cupressus sempervirens was obtained by hydrodistillation and analysed using gas chromatography–flame ionization detection (GC–FID) and gas chromatography–mass spectrometry (GC–MS). Two monoterpenes, α-pinene (49.1%) and δ-3-carene (21.4%), and one sesquiterpene hydrocarbon, α-cedrol (5.1%), were isolated as the EO major terpenes. An oil-in-water nanoemulsion (particle size 71.2 nm) was produced from the EO through a low-energy method. The EO, its nanoemulsion and its main constituents showed mosquitocidal and biochemical effects against Culex quinquefasciatus Say, the common vector of lymphatic filariasis parasites. All treatments showed dose-dependent bioactivity, and adults were more susceptible to the EO products than the larvae. The nanoemulsion showed superior activity, followed by the crude EO and α-cedrol. At 40 μg/ml, the nanoemulsion caused 100% larval mortality, while the EO and α-cedrol required twice this concentration to achieve the same larval mortality. The LC₅₀ values were 8.4, 16.1, 15.1, 30.7 and 53.4 μg/ml at 24 h after exposure for the nanoemulsion, crude oil, α-cedrol, δ-3-carene and α-pinene, respectively. For adults, 20.0 μl/l nanoemulsion caused 100% mortality, while twice this concentration of the EO was required to achieve the same effect. The LC₅₀’s against adults ranged between 6.2 and 40.4 μl/l. EO products prominently repelled mosquitoes at concentrations between 0.75 and 6.0 μl/cm². The EO products caused remarkable inhibition of Cx. quinquefasciatus acetylcholinesterase activity but were safer towards the non-target aquatic species Gambusia affinis. These results recommend the use of C. sempervirens EO, its nanoemulsion and main terpenes as natural tools to control Cx. quinquefasciatus.
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