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The scientometric analysis of the research on microalgae-based wastewater treatment Full text
2021
Li, Zhuo | Zhu, Liandong
This study explores the characteristics of the literature on microalgae-based wastewater treatment during the past 20 years, based on the Web of Science Core Collection database and its scientometric techniques. The results reveal that the literature on microalgae-based wastewater treatment has grown rapidly with 2621 publications and 54,388 citations in total. Most of the document types are journal articles, constituting 80.7% of the total records. China and the USA are the two most active countries, regarding the publications and cooperation in this filed from the viewpoint of the number of publishing papers, total number of citations, and the number of multinational author papers. The Chinese Academy of Sciences is the largest institutional contributor, publishing 2.3% of the papers, followed by the Indian Institute of Technology (2.2%) and Council of Scientific & Industrial Research (2.1%). The most publishing author is Ruan (35 papers) with the highest number of citation (2460 times). “Bioresource Technology” is the most publishing journal with 365 published papers, while 36.2% of the total sample is published in the subject area of “Environmental Sciences Ecology.” The most cited paper in the past 20 years is a review of the status of phosphorus removal in wastewater by de-Bashan in 2004. Bibliometric analysis has systematically combed the development system of microalgae-based wastewater treatment in the past 20 years and has a great potential to gain valuable insights for the future development, which provides a supplement to the common content analysis.
Show more [+] Less [-]Preservative potential of biosynthesized silver nanoparticles: prevention of xylem occlusion and microbial proliferation at postharvest stage of preservation Full text
2021
Das, Dipayan | Ghosh, Debasmita | Mandal, Palash
The purpose of the current study was to determine the appropriate genotype and concentration of biosynthesized silver nanoparticles effectual in preserving mulberry leaves at the postharvest stage. The preservative effect of silver nanoparticles was determined by their potentiality to prevent xylem blockage, chlorophyll content retention and inhibition of microbial proliferation within a preservative solution. For synthesizing silver nanoparticles, a blend of 10⁻³ M silver nitrate and S1 genotype of the mulberry leaf was found to be most effective. Silver nanoparticles at 6 ppm were observed to be the least effective concentration for preserving mulberry leaves for at least 7 days at the postharvest stage, as evident from physical texture and retention of chlorophyll content. Biosynthesized silver nanoparticles showed negative microbial count during the course of preservation as evident from no colony-forming unit (CFU) until the last day of preservation, while conventional preservative silver nitrate showed traces of CFU on a nutrient agar plate. Besides, these leaves preserved in nanosilver solution showed an almost negligible number of xylem blockage in the petiole, almost equivalent to the blockage nature of fresh leaves caused by the deposition of macromolecules like protein, lignin and suberin. Nanosilver- and silver nitrate–preserved leaves also displayed insignificant accumulation of reactive oxygen species (ROS) and greater retention of membrane integrity than leaves preserved in normal distilled water. Nanosilver solution showed greater durability of preserving mulberry leaves than conventional floral preservative silver nitrate, useful for feeding silkworm larvae during the rainy season.
Show more [+] Less [-]Detecting urban landscape factors controlling seasonal land surface temperature: from the perspective of urban function zones Full text
2021
Li, Tong | Xu, Ying | Yao, Lei
Understanding the impact on the thermal effect by urbanization is of great significance for urban thermal regulation and is essential for determining the relationship between the urban heat island (UHI) effect and the complexities of urban function and landscape structure. For this purpose, we conducted case research in the metropolitan region of Beijing, China, and nearly 5000 urban blocks assigned different urban function zones (UFZs) were identified as the basic spatial analysis units. The seasonal land surface temperature (LST) retrieved from remote sensing data was used to represent the UHI characteristics of the study area, and the surface biophysical parameters, building forms, and filtered landscape pattern metrics were selected as the urban landscape factors. Then, the effects of urban function and landscape structure on the UHI effect were examined based on the optimal results of the ordinary least squares and geographically weighted regression models. The results indicated that (1) Significant spatiotemporal heterogeneity of the LST was found in the study area, and there was an obvious temperature gradient with “working–living–resting” UFZs. (2) All types of urban landscape factors showed a significant contribution to the seasonal LST, in the order of surface biophysical factors > building forms > landscape factors; however, their contributions varied in different seasons. (3) The major contributing factors showed a certain difference due to the variation of urban function and landscape complexity. This study expands the understanding on the complex relationship among urban landscape, function, and thermal environment, which could benefit urban landscape planning for UHI alleviation.
Show more [+] Less [-]Evaluation of sustainable groundwater utilization using index methods (WQI and IWQI), multivariate analysis, and GIS: the case of Akşehir District (Konya/Turkey) Full text
2021
Şener, Şehnaz | Varol, Simge | Şener, Erhan
Akşehir district is one of the regions where significant agricultural production and industrial activities are carried out. Groundwater is the most important water resource in this region used for different purposes, especially for drinking and irrigation water. In order to ensure sustainable water management in the study area, it is necessary to reveal the drinking and irrigation water quality of groundwater and to take precautions and determine the management plans. In the present study, groundwater quality was evaluated using water quality index methods (WQI and IWQI) and statistical analyses to determine the sustainable and most appropriate usage of groundwater. In addition, spatial distribution maps were prepared using GIS for drinking and irrigation WQI assessments of the groundwater. A total of 31 groundwater samples were collected from wells in October 2018 and physicochemical analysis results were evaluated. According to the results obtained with the WQI method, all groundwater samples in the study area are definitely not suitable for use as drinking water. According to the results obtained by the IWQI method, samples S23, S24, S25, S27, S28, S29, and S31 especially are not suitable for use as irrigation water. Statistical evaluations support the results obtained from WQI and IWQI methods. Also, factor analysis indicates that anthropogenic pollution, especially agricultural applications, is effective on the chemical and quality characteristics of groundwater samples in addition to the geological properties. As seen in the spatial distribution maps for WQI and IWQI results, while the quality of groundwaters around Doğruözü and Erdoğdu is not suitable for drinking water, the groundwater quality in the north-east of the study area is also unusable for irrigation water. Consequently, the use of groundwater in the region as drinking water can be dangerous for human health and alternative drinking water resources should be investigated. In addition, in order to ensure the sustainable use of groundwater, it is necessary to control agricultural activities in the region, to monitor the use of pesticides and fertilizers, and to encourage organic farming practices in the region.
Show more [+] Less [-]Effects of atrazine short-term exposure on jumping ability and intestinal microbiota diversity in male Pelophylax nigromaculatus adults Full text
2021
Zhao, Qiang | Huang, Minyi | Liu, Yang | Wan, Yuyue | Duan, Renyan | Wu, Lianfu
Atrazine, a common chemical pesticide, has toxicity to adult and juvenile amphibians in natural ecosystems; however, it is more common to study its effects on larvae instead of adults. This study assessed the impacts of atrazine in water through short-term exposure (7 days) on male black spotted frog (Pelophylax nigromaculatus) adults fed every day. The jumping ability, including jumping height, distance, time, and speed, was measured by 3D motion analysis software, and the intestinal content microbiota was determined by 16S rRNA amplicon sequencing with QIIME software. The results showed that male P. nigromaculatus exposure to 200 and 500 μg/L atrazine significantly increased jumping distance and jumping time compared to control groups. Conversely, 500 μg/L atrazine treatments significantly decreased the diversity and changed the composition and structure of intestinal content microflora in male P. nigromaculatus compared to control groups. At the phylum level, Chlamydiae was only detected in the control group, and Actinobacteria, Bacteroidetes, Firmicutes, Fusobacteria, and Proteobacteria were the dominant microflora in the atrazine treatment groups. At the genus level, the abundance of Lactobacillus and Weissella significantly increased in atrazine treatment groups compared to control groups. This study can provide a new framework based on movement behavior and intestinal microbiota to evaluate the response of amphibians to short-term exposure to environmental pollution.
Show more [+] Less [-]Chitosan Versus Chitosan-Vanillin Modified: An Evaluation of the Competitive Adsorption of Five Emerging Contaminants Full text
2021
dos Santos Cardoso, Carolina | Vitali, Luciano
Emerging contaminants (ECs) have been studied extensively because of the various damages they can cause to the environment, especially due to the non-treated domestic effluents, which contaminate the water bodies. Therefore, it is important to evaluate alternatives to remove these compounds. The objective of this work was to evaluate the potential of a new biosorbent from chitosan modified with vanillin (CTSV) to remove isoniazid, cortisol, bisphenol A, 17α-ethinylestradiol, and triclosan by competitive adsorption studies. Structural characterization of the biosorbents was performed by Fourier transform infrared spectroscopy, thermogravimetry, Brunauer-Emmett-Teller, zeta potential, scanning electron microscopy, and ¹H nuclear magnetic resonance. The adsorption for ECs were carried out in an aqueous medium, and quantitative analyzes were performed by HPLC. The effect of pH was evaluated in the pH range 5 to 10 and indicated that better results were found in pH 9 and 8 for CTS and CTSV, respectively. The salt concentrations effect was evaluated in 0.0 to 1.0 mol L⁻¹ and revealed better adsorption conditions in 0.7 mol L⁻¹ of NaCl. The adsorption kinetics pointed to an equilibrium condition reached quickly (with adjustment of data R² > 0.969) with adequacy to pseudo–second-order model for both biosorbents and ECs. The linear isothermal model was suitable for the adsorption isothermal data and distribution constant (KD) showed the highest values for 17α-ethinylestradiol (0.067 L g⁻¹) and triclosan (0.197 L g⁻¹) in CTSV adsorption. Thus, the results indicated that CTSV performed well in removal for the tested ECs, being an interesting alternative, due to the ease of obtaining and abundance of reagents employed in its preparation.
Show more [+] Less [-]Prevalence of hearing loss and influencing factors among workers in Wuhan, China Full text
2021
Li, Wenzhen | Zhao, Zhiya | Chen, Zhenlong | Yi, Guilin | Lu, Zuxun | Wang, Dongming
We aimed to estimate the prevalence of hearing loss and influencing factors among workers in automobile manufacturing industry in Wuhan, China. We conducted cross-sectional analyses of 2017 through 2019 data from survey of the key occupational diseases on 17,176 workers in automobile manufacturing industry, Wuhan, China. Hearing loss was defined as a pure tone mean of 25 dB or higher in either ear at 0.5, 1, and 2 kHz for speech frequency and at 3, 4, and 6 kHz for high frequency. Among the 17,176 workers, more than a quarter of participants had high frequency hearing loss, and 6.41% had speech frequency hearing loss. The prevalence of hearing loss was higher among participants with diabetes mellitus and current smoking, temporary tinnitus, and sudden change in hearing. Compared with the controls, age (OR = 1.08, 95% CI = 1.08–1.09), male (OR = 1.40, 95% CI = 1.21–1.63), occupational noise exposure (OR = 1.19, 95% CI = 1.08–1.30), having temporary tinnitus (OR = 1.20, 95% CI = 1.08–1.33), and having sudden change in hearing (OR = 1.58, 95% CI = 1.20–2.08) were associated with higher prevalence of high frequency hearing loss; meanwhile, age (OR = 1.09, 95% CI = 1.08–1.09), male (OR = 1.38, 95% CI = 1.11–1.71), having family history of hearing loss (OR = 2.84, 95% CI = 1.35–5.97), and having sudden change in hearing (OR = 2.58, 95% CI = 1.80–3.70) were associated with higher prevalence of speech frequency hearing loss. No additive and multiplicative interaction was found between occupational noise and these factors for hearing loss. Hearing loss directly affects 25% of workers in automobile manufacturing industry in Wuhan. Measures should be implemented for the control of occupational noise and other factors simultaneously in the workplace.
Show more [+] Less [-]Outdoor/Indoor Contaminant Transport by Atmospheric Dust and Aerosol at an Active Smelter Site Full text
2021
Rodríguez-Chávez, Tania B. | Rine, Kyle P. | Almusawi, Reman M. | O’Brien-Metzger, Ruby | Ramírez-Andreotta, Mónica | Betterton, Eric A. | Sáez, A. Eduardo
Activities associated with mining operations including smelting, ore handling, and mine tailings management have been identified as sources of dust and aerosol that may contain metal and metalloid contaminants, such as lead (Pb) and arsenic (As). Previous studies on contaminant transport have concentrated on the potential impact of these particulate emissions in outdoor environments. The purposes of this study were (i) to quantify the effect of dust and aerosol particle size on contaminant transport from outdoor-to-indoor environments and (ii) to document the changes in particle chemical composition during transport through the outdoor/indoor barrier. Outdoor and indoor particulate samples were collected at a high school equipped with mechanical air filtration systems from 2016 to 2019. The school is located near a set of mine tailings and an active copper smelter in Hayden, Arizona. Particle size segregated samples were collected using a ten-stage micro-orifice uniform deposit impactor (MOUDI). Results show that airborne fine particles (aerodynamic diameters less than 1 micron) can penetrate to the indoor environment but in a reduced amount due to mechanical filtration. Aerosol in the fine fraction particulate air concentrations was around 50% of the corresponding outdoor values, but their mass concentration of contaminants was similar to outdoor values. Indoor coarse particles (> 1 micron) comprised close to 20% of the levels found in outdoor coarse particles. These results highlight the need to consider the impact of particle diameter when assessing indoor exposure and potential health effects in communities living under the direct influence of mining and smelter activities.
Show more [+] Less [-]Application of an electrochemical sensor using copper oxide nanoparticles/polyalizarin yellow R nanocomposite for hydrogen peroxide Full text
2021
Amini, Nader | Rashidzadeh, Bahaaldin | Amanollahi, Nasrin | Maleki, Afshin | Yang, Jae-Kyu | Lee, Seung-Mok
In this study, copper oxide nanoparticles (CuONPs) were prepared by a simple chemical method and then characterized by scanning electron microscope (SEM). A novel electrochemical sensor for hydrogen peroxide (H₂O₂) analysis was prepared by immobilizing copper oxide nanoparticles and polyalizarin yellow R (PYAR) on bare glassy carbon electrode (PAYR/CuONPs/GCE). The electrocatalytical behavior of the proposed electrochemical sensor was also studied by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV). Based on the results, the PAYR/CuONP nanocomposite had significant electrocatalytic oxidation and reduction properties for the detection and determination of H₂O₂. Some parameters such as linear range, sensitivity, and detection limit for reduction peak were obtained as 0.1–140 μM, 1.4154 μA cm⁻² μM⁻¹, and 0.03 μM, respectively, by the DPV technique. Some advantages of this electrode were having widespread linear range, low detection limit, and, most importantly, ability in simultaneous oxidation and reduction of H₂O₂ at two applied potentials.
Show more [+] Less [-]Co-disposal of lignite fly ash and coal mine waste rock for neutralisation of AMD Full text
2021
Qureshi, Asif | Maurice, Christian | Öhlander, Björn
Waste rocks (WRs) from a lignite-producing coalfield and fly ash (FA) produced from the same lignite have been investigated in this study with a primary objective to determine the potential for co-disposal of WRs and FA to reduce the environmental contamination. Mixing WRs with FA and covering WRs with FA have been investigated. Particle size effect caused ≤2 mm particles to produce low pH (~2) and metal-laden leachates, indicating higher sulphide minerals’ reactivity compared to larger particles (≤10 mm, pH ~ 4). Co-disposal of FA as mixture showed an instantaneous effect, resulting in higher pH (~3–6) and better leachate quality. However, acidity produced by secondary mineralisation caused stabilisation of pH at around 4.5–5. In contrast, the pH of the leachates from the cover method gradually increased from strongly acidic (pH ~ 2) to mildly acidic (pH ~ 4–5) and circumneutral (pH ~ 7) along with a decrease in EC and elemental leaching. Gradually increasing pH can be attributed to the cover effect, which reduces the oxygen diffusion, thus sulphide oxidation. FA cover achieved the pH necessary for secondary mineralisation during the leaching experiment. The co-disposal of FA as cover and/or mixture possesses the potential for neutralisation and/or slowing down AMD and improving leachate quality.
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