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RELATIONSHIPS BETWEEN STABILITY, MATURITY, WATER EXTRACTABLE ORGANIC MATTER OF MUNICIPAL SEWAGE SLUDGE COMPOSTS AND SOIL FUNCTIONALITY
No full textCompost capability of restoring or enhancing soil quality depends on several parameters, such as soil characteristics, compost carbon, nitrogen and other nutrient content, heavy metal occurrence, stability and maturity. This study investigated the possibility of relating compost stability and maturity to water-extractable organic matter (WEOM) properties and amendment effect on soil quality. Three composts from municipal sewage sludge and rice husk (AN, from anaerobic wastewater treatment plants; AE, from aerobic ones; MIX, from both anaerobic and aerobic ones) have been analysed and compared to a traditional green waste compost (GM, from green manure, solid waste and urban sewage sludge). To this aim, WEOMs were characterized through chemical analysis; furthermore, compost stability was evaluated through oxygen uptake rate calculation and maturity was estimated through germination index determination, whereas compost impact on soil fertility was studied, in a lab-scale experiment, through indicators as inorganic nitrogen release, soil microbial biomass carbon, basal respiration rate and fluorescein di-acetate hydrolysis. The obtained results indicated that WEOM characterization could be useful to investigate compost stability (which is related to protein and phenol concentrations) and maturity (related to nitrate/ammonium ratio and degree of aromaticity) and then compost impact on soil functionality. Indeed, compost stability resulted inversely related to soil microbial biomass, basal respiration rate and fluorescein di-acetate hydrolysis when the products were applied to the soil
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
Degradazione di nonilfenoli polietossilati in un bioreattore aerobico a cellule immobilizzate su una schiuma ceramica (Vukopor® S10)
No full textI nonilfenoli polietossilati (NPnEO, n è il numero di unità etossiliche) sono tensioattivi non ionici sintetici, largamente utilizzati come detergenti nelle industrie tessile e conciaria e come emulsionanti in diversi prodotti per l’igiene personale. I reflui acquosi contenenti NPnEO sono generalmente inviati ad impianti di trattamento a fanghi attivi, in cui i NPnEO sono bioconvertiti in molecole a più basso grado di etossilazione (n=1,2 e 3) e 4-nonilfenolo (4-NP) [1]. Queste molecole tendono a persistere in diversi comparti ambientali, in particolare nelle acque reflue e superficiali, attraverso le quali si accumulano nei tessuti adiposi della fauna ittica esercitando effetti tossici dovuti al loro potere estrogeno-mimetico. Si rende, quindi, necessaria l’adozione di un trattamento terziario attraverso il quale abbattere completamente i NPnEO ed i loro prodotti di degradazione. Ad oggi, tale trattamento consiste in uno stadio di ozonizzazione, che è efficace ma ha alti costi di gestione e presenta problemi a causa della produzione di intermedi altamente reattivi.
La presente ricerca si inserisce in un progetto mirato a mettere a punto un trattamento terziario alternativo più economico e che non porti alla formazione di intermedi tossici. In studi precedenti sono stati allestiti dei bioreattori aerobici a letto fisso impaccati con due diversi supporti, Carbone Attivo Granulare (GAC) e Silice Manville (SM). Tali sperimentazioni hanno fornito buoni risultati in termini di rimozione dei NPnEO da un’acqua contaminata artificialmente da miscele commerciali di NPnEO, ma si è osservato un parziale sgretolamento dei supporti utilizzati.
In questo lavoro è stato testato, in un sistema analogo, un nuovo supporto di immobilizzazione, il Vukopor® S10, una schiuma ceramica a base di SiC ed Al2O3, caratterizzata da elevata resistenza meccanica e termica ed utilizzata generalmente come materiale filtrante. Tale schiuma si è prestata molto bene alla funzione di materiale di riempimento del bioreattore, presentando valori di biomassa adesa, per unità di peso secco di supporto, molto più elevati rispetto a quelli riscontrati con l’uso di altri supporti (circa 12 mg/g di supporto secco vs 0,4 e 1,5 mg/g di GAC e SM rispettivamente). Come biocatalizzatore del sistema è stato utilizzato un consorzio microbico (Consorzio A) isolato da acque reflue contaminate da NPnEO in presenza di 4-NP come substrato di selezione ed in grado di utilizzare l’Igepal CO-520 (miscela commerciale di NPnEO con grado di etossilazione medio pari a 5) come fonte di carbonio ed energia. Il sistema è stato avviato in regime batch, prima in presenza di 4-NP e poi di Igepal CO-520, e successivamente forzato ad operare in regime continuo in presenza di Igepal CO-520 come fonte di carbonio. Durante la sperimentazione è stata monitorata sia la rimozione dell’inquinante, mediante analisi HPLC dei tensioattivi presenti nel brodo colturale, sia la sua mineralizzazione, determinata in base alla quantità di CO2 prodotta e misurata attraverso la titolazione di una soluzione di NaOH posta sulla linea di sfiato dei gas. I risultati ottenuti mostrano che il processo sviluppato è in grado di degradare l’Igepal CO-520 sia in regime batch, ottenendo una elevata percentuale di rimozione globale (75% dei tensioattivi immessi nel sistema), sia in regime continuo (48%). Il dato di maggiore interesse riguarda la percentuale di mineralizzazione dell’inquinante (95% in regime batch e 96% in regime continuo, con riferimento all’Igepal rimosso). In conclusione, il supporto utilizzato in questo studio ha evidenziato un’elevata capacità di immobilizzare biomassa, superiore ai supporti precedentemente utilizzati senza subire alterazioni meccaniche nel corso della sperimentazione, ed il reattore allestito ha presentato un’attività di rimozione e mineralizzazione elevata, confrontabile con quella presentata dagli altri materiali sperimentati.
[1] Terzic S, Matosic M, Ahel M, Mijatovic I, 2005..
Biodegradazione di nonilfenoli etossilati mediante l’impiego di bioreattori a cellule immobilizzate
No full textOrganic wastes as alternative sources of phosphorus for plant nutrition in a calcareous soil
No full textRecycled organic wastes (OW) can be a valuable P source; however, their P-fertilising capacity is still poorly known. In this study, we selected three anaerobic digestates [wastewater sludge (D-1), winery sludge (D-2), and bovine-slurry/energy crops (BD)] and two animal effluents [bovine slurry (BS) and swine slurry (SS)] to test their P-release and P-fertilising capacities via sequential chemical extraction (SCE), X-ray diffraction (XRD), and P-31-nuclear magnetic resonance (P-31 NMR). Subsequently, the three digestates (30 mg P kg(-1) of soil) were compared for the release of Olsen-P during a soil incubation and for plant-P apparent recovery (ARF) in a pot experiment using ryegrass (112 days) in a soil with poorly available-P (Olsen-P < 5 mg kg(-1)), under a non-limiting N environment. The amount of labile-P (H2O + NaHCO3), as determined from SCE, related well to the Olsen-P following OW addition to the soil. It was shown via P-31 NMR spectroscopy that orthophosphate was the leading P-form in highly P-releasing OW. The amount of labile-P, however, was affected by soil adsorption, thereby reducing plant-P uptake. The plant-P ARF (%) showed that the recycled P-sources were clustered in highly (BD and SS: approximate to 20%), intermediately (D-1 and BS: approximate to 15%) and poorly performing OWs (D-2: approximate to 10%) vs. chemical P-source (P-chem: 20%). Therefore, only BD and SS were effective alternatives to P-chem; however, the other OW can be efficient P-sources in soils with higher Olsen-P. Thus, crop fertilisation can be tailored on a P-basis by SCE as a function of soil adsorption capacity and on an N-basis according to the demand. (C) 2019 Elsevier Ltd. All rights reserved
Nonylphenol polyethoxylate biodegradation in acqueous waste by the use of a batch and continuous packed-bed aerobic bioreactor
No full textAn aerobic bacterial consortium (Consortium A) was recently isolated from textile wastewater and tested to be able of degrading a variety of nonylphenol polyethoxylates (NPnEOs) congeners as well as an industrial mixture of branched side-chain isomers of 4-nonylphenol (4-NP) using them as the sole carbon and energy source. In the perspective of developing a biotechnological process for the treatment of effluents from activated sludge plants fed with NPnEO contaminated wastewater, the capability of Consortium A of biodegrading two industrial mixtures of NPnEOs in the condition of immobilized cells was investigated. A packed-bed bioreactor has been developed by immobilizing the consortium on an innovative ceramic material (Vukopor® S10) by re-circulating Consortium A cells growing on a 4-NP contaminated water under batch conditions. Two different NPnEO mixtures were subsequently tested as the only carbon sources. The experimental approach was then defined as follows: the reactor was fed with the first mixture (IgepalCO-520: average ethoxylation degree of 5), operated under batch conditions for a brief period and then it was switched to the continuous mode. The same was done feeding the reactor with the second mixture (IgepalCO-210: average ethoxylation degree of 1,5). The reactor was monitored through chemical, microbiological and molecular integrated methodology. Both experiments displayed comparable NPnEO mineralization under batch and continuous conditions. DGGE analyses were running on the DNA extracted from the liquid phases and from the biofilm developed on supports at the end of the two experiments, to determine the spatial distribution of Consortium A microorganisms mostly involved in NPnEO biodegradation. The data collected in this study provide a preliminary strong indication on the feasibility of Consortium A-based biofilm technology for the decontamination of NPnEO containing effluents
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
Organic wastes as alternative sources of phosphorus for plant nutrition in a calcareous soil
No full textRecycled organic wastes (OW) can be a valuable P source; however, their P-fertilising capacity is still poorly known. In this study, we selected three anaerobic digestates [wastewater sludge (D1), winery sludge (D2), and bovine-slurry/energy crops (BD)] and two animal effluents [bovine slurry (BS) and swine slurry (SS)] to test their P-release and P-fertilising capacities via sequential chemical extraction (SCE), X-ray diffraction (XRD), and 31P-nuclear magnetic resonance (31P NMR). Subsequently, the three digestates (30 mg P kg−1 of soil) were compared for the release of Olsen-P during a soil incubation and for plant-P apparent recovery (ARF) in a pot experiment using ryegrass (112 days) in a soil with poorly available-P (Olsen-P < 5 mg kg−1), under a non-limiting N environment. The amount of labile-P (H2O + NaHCO3), as determined from SCE, related well to the Olsen-P following OW addition to the soil. It was shown via 31P NMR spectroscopy that orthophosphate was the leading P-form in highly P-releasing OW. The amount of labile-P, however, was affected by soil adsorption, thereby reducing plant-P uptake. The plant-P ARF (%) showed that the recycled P-sources were clustered in highly (BD and SS: ≈20%), intermediately (D1 and BS: ≈15%), and poorly performing OWs (D2: ≈10%) vs. chemical P-source (P-chem: 20%). Therefore, only BD and SS were effective alternatives to P-chem; however, the other OW can be efficient P-sources in soils with higher Olsen-P. Thus, crop fertilisation can be tailored on a P-basis by SCE as a function of soil adsorption capacity and on an N-basis according to the demand
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