1,720,956 research outputs found
Removal of microplastics in wastewater treatment plants: insights from a literature meta-analysis
Full text linkThe rising environmental presence of microplastics (MPs) has generated growing concern, particularly regarding their potential environmental and human health risks. Wastewater treatment plants (WWTPs) are key terrestrial pathways for MPs emission into aquatic ecosystems, despite their high MPs removal efficiency. This study analyzes 147 published papers, covering 509 real WWTPs. Over 200 information fields were stored for each case study, including plant configuration, operating parameters, and MPs characteristics (size, polymer type and shape). The database enables comparative analyses of MPs concentrations and removals throughout the WWTPs, evaluating the influence of factors such as treated wastewater origin, treatment level, plant size and location. The meta-analysis on literature data highlights that influent MPs concentrations vary widely, primarily influenced by wastewater origin and WWTP size. Industrial WWTPs show significantly higher influent concentrations than municipal or mixed wastewater, while small-scale plants report lower median values. MPs removal rates vary by treatment level, achieving medians of 45.9% at primary outlet and 95.0% at tertiary outlet. The study also explores the influence of particle size, polymer type, and shape on MPs removals. Despite high overall efficiencies, significant data gaps persist, particularly regarding operating conditions and the fate of MPs in sludge. This work underscores the urgent need for standardized methodologies in MPs sampling, characterization, and analysis. Establishing guidelines for reporting operating parameters will enable more robust evaluations and comparability of WWTPs performances and MPs behavior. Addressing these gaps, will refine strategies to mitigate MPs pollution and improve WWTP designs for environmental protection
How does alkaline-thermal pretreatment followed by anaerobic digestion affect the content of polyethylene terephthalate and polyamide 66 microplastics?
Full text linkMicroplastics (MPs) are ubiquitous and increasing in quantity, causing raising concern. Wastewater treatment plants (WWTPs) are a point source for both aquatic environments and soil, through the use of sludge in agriculture. Understanding the fate of MPs within the wastewater and sludge lines of a treatment plant and, possibly, enhancing their removal will improve the safe reuse of sludge and water effluent and the wastewater biorefinery concept application. This study investigates the effects of alkaline-thermal pretreatment of sludge, followed by anaerobic digestion, on the physical and chemical characteristics of polyethylene terephthalate (PET) and polyamide 66 (PA(66)) contained. Experiments were conducted to evaluate the influence of different NaOH concentrations, temperatures, and reaction times on the degradation of the MPs in anaerobic digestion. PET MPs exhibited relevant mass reduction and structural changes in relation to the NaOH concentration and temperature. PA(66) MPs showed limited chemical alterations, indicating higher resistance to degradation. Batch anaerobic digestion tests of pretreated samples did not modify them further. Chemical characterization of MPs was performed using both Attenuated Total Reflectance-Fourier Transform Infrared spectroscopy (ATR-FTIR) and Focal Plane Array-Fourier Transform-Imaging-Micro-Spectroscopy (FPA-μFTIR-Imaging), revealing distinct trends between surface-level and bulk material changes in the MPs. The results highlighted that ATR-FTIR recorded lower carbonyl index values compared to FPA-μFTIR-Imaging. These findings emphasized the importance of using complementary analytical techniques to thoroughly understand MPs degradation. The outcomes suggest that tailored pretreatment strategies are essential to enhance MPs removal in WWTPs, ensuring safer sludge reuse within a circular economy framework.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
