Sustainable Strategy for Enhancing Anaerobic Digestion of Waste Activated Sludge: Driving Dissimilatory Iron Reduction with Fenton Sludge

The Fenton process has been extensively applied for treatment of refractory organic pollutants. The potentially hazardous iron-containing sludge generated from the Fenton process requires proper treatment and disposal, due to its high Fe contents and toxic organic matter involved. Considering that Fe­(III) oxides exhibit an ideal potential for enhancing anaerobic digestion (AD), in this study Fenton sludge with a high abundance of Fe­(III) was introduced in the AD of waste activated sludge (WAS) with the aim to improve sludge digestion as well as to remove the organic matter in Fenton sludge. Results showed that methane production and sludge reduction of WAS were significantly improved, and the organic matter contained in Fenton sludge was removed by 70.0%. Meanwhile, nearly half of Fenton sludge was converted to Fe²⁺ via dissimilatory iron reduction during the digestion, in agreement with the microbial community analysis. The study suggests an Fe recycling between AD and the Fenton process and that Fenton sludge can be used as an iron source to enhance AD, during which most of the harmful organic matter in Fenton sludge was removed, and Fe­(II) generated can serve as a reactant again for a new Fenton reaction

New Application of Ethanol-Type Fermentation: Stimulating Methanogenic Communities with Ethanol to Perform Direct Interspecies Electron Transfer

Direct interspecies electron transfer (DIET) has been considered as an effective mechanism to proceed syntrophic methanogenic metabolism. However, up to now, this working mode has been still not widely established in the <i>Geobacter</i>-rare methanogenic digesters. In this study, a strategy that could enrich <i>Geobacter</i> species and stimulate the methanogenic communities to continuously perform DIET was proposed in a two-phase anaerobic digestion (AD) system with the aim to enhance and stabilize the better AD. The results demonstrated that, under the conditions employed, the ethanol-abundant acidogenic products could be produced via ethanol-type fermentation when acidogenic-phase pH was kept at 4.0–4.5. Enrichments in the methanogenic phase continuously stimulated with the ethanol-abundant acidogenic products presented a higher conductivity, as well as more positive response to granular activated carbon (GAC) supplemented, compared with the enrichments without this stimulation, suggesting that DIET might be established. Microbial community analysis showed that <i>Geobacter</i> species were only detected in the methanogenic enrichments stimulated by the ethanol-abundant acidogenic products. Together with the significant increase of <i>Methanosarcina</i> species in these enrichments, the potential DIET between <i>Geobacter</i> and <i>Methanosarcina</i> species might be permanently established in the methanogenic digester to maintain the acidic balance as well as syntrophic metabolism stable

Application of Biuret, Dicyandiamide, or Urea as a Cathode Buffer Layer toward the Efficiency Enhancement of Polymer Solar Cells

Three amino-containing small-molecule organic materialsbiuret, dicyandiamide (DCDA), and ureawere successfully applied as novel cathode buffer layers (CBLs) in P3HT:PCBM bulk heterojunction polymer solar cells (BHJ-PSCs) for the first time, resulting in obvious efficiency enhancement. Under the optimized condition, the power conversion efficiencies (PCEs) of the CBL-incorporated BHJ-PSC devices are 3.84%, 4.25%, and 4.39% for biuret, DCDA, and urea, which are enhanced by ∼15%, ∼27%, and ∼31%, respectively, compared to the reference poly­(3-hexylthiophene-2,5-diyl) : [6,6]-phenyl-C₆₁-butyric acid methyl ester (P3HT:PCBM) BHJ-PSC device without any CBL. The efficiency enhancement is primarily attributed to the increases of both short-circuit current density (<i>J</i>_sc) and fill factor (FF), for which the enhancement ratio is found to be sensitively dependent on the molecular structure of small-molecule organic materials. The surface morphologies and surface potential changes of the CBL-incorporated P3HT:PCBM photoactive layers were studied by atomic force microscopy and scanning Kelvin probe microscopy, respectively, suggesting the formation of an interfacial dipole layer between the photoactive layer and Al cathode, which may decrease the energy level offset between the work function of Al and the lowest unoccipoed molecular orbital level (LUMO) of the PCBM acceptor and consequently facilitate electron extraction by the Al cathode. The difference in the enhancement effect of biuret, DCDA, and urea is due to their difference on the work function matching with P3HT:PCBM. Besides, the coordination interaction between the lone-pair electrons on the N atoms of the amino (−NH₂) group and the Al atoms may prohibit interaction between Al and the thiophene rings of P3HT, contributing to the efficiency enhancement of the CBL-incorporated devices as well. In this sense, the different CBL performance of biuret, DCDA, and urea is also proposed to partially originate from the differences on their chemical structure, specifically the number of amino groups

Recognition by spectrum of simple groups C (p) (2)

It is proved that, if G is a finite group that has the same set of element orders as the simple group Cp(2) for prime p &gt; 3, then G/O2(G) is isomorphic to Cp(2). © 2012 Pleiades Publishing, Ltd

Training of future primary school teachers in the Czech Republic and Belgium

This thesis deals with a training of primary school teachers in the Czech Republic and in the French-speaking part of Belgium. It is a comparative study analyzing corresponding systems of tertiary education. In detail it describes selected examples of education used by the Faculty of Education of Charles University in Prague and the École normale catholique du Brabant Wallon at Haute Ecole Léonard de Vinci in Louvain - la - Neuve. For the purpose of mutual inspiration it presents individual curricula of both universities, the relationship of theory and practice in the studies and, based on author`s own observations and experience, reflections of two specific issues from each institution which are interesting and unique. It also presents problems of professional competence of teachers who apply for teacher training. Because such paper is already valid in Belgium, while in the Czech Republic it is still in progress. Both schools have a lot to offer for its current students, but there is always space for further development

Cavum septum pellucidum and first-episode psychosis: A meta-analysis

<div><p>Objectives</p><p>To investigate the prevalence and changes of cavum septum pellucidum (CSP) in first-episode psychosis (FEP) patients.</p><p>Methods</p><p>Medline, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched to identify eligible studies comparing FEP patients and healthy controls from inception to Feb 29, 2016.</p><p>Results</p><p>Ten cross-sectional studies and three longitudinal studies reported in ten articles met our criteria. Our meta-analysis found no significant differences in the prevalence of either “any CSP” (OR = 1.41; 95% CI 0.90–2.20; p = 0.13; I² = 52.7%) or “large CSP” (OR = 1.10; 95% CI 0.77–1.58; p = 0.59; I² = 24.1%) between FEP patients and healthy controls. However, the heterogeneity analysis of the prevalence of “any CSP” suggested bias in outcome reporting.</p><p>Conclusions</p><p>The results based on current evidence suggest it is unclear whether “any CSP” is a risk factor for FEP due to the heterogeneity of the studies. There is insufficient evidence to support that “large CSP” is a possible risk factor for FEP.</p></div

Cavum septum pellucidum and first-episode psychosis: A meta-analysis - Fig 4

<p>Meta-regression of “any CSP” according to (1) the sex ratio (male/female) in the FEP patients; (2) the sex ratio (male/female) in the healthy controls; and (3) the mean age of the healthy controls.</p

Funnel plot of the prevalence of “large CSP” in the FEP patients.

<p>Funnel plot of the prevalence of “large CSP” in the FEP patients.</p

Forest plot of the efficacy rate of SMT-treated FD after subgroup analysis of the different kinds of control interventions among SMT versus WM.

<p>SMT = Si-Mo-Tang oral liquid, WM = western medicine, FD = functional dyspepsia.</p

The risk of bias assessment with the Cochrane Collaboration tool.

<p>(A)Risk of bias graph. (B)Risk of bias summary.</p