Nitrogen removal in a Sequencing Batch Biofilm Reactor : effect of carbon availability and intermittent aeration

This study aimed to investigate the effects of carbon availability and intermittent aeration on nitrogen removal in a Sequencing Batch Biofilm Reactor (SBBR). The percentage of nitrogen removal in the SBBRs operating with dump fill and slow fill with optimum intermittent aeration was quite similar, 75.7% and 69.2%, respectively, indicating that intermittent aeration allowed a considerable energy saving without compromising significantly nitrogen removal. Accumulation of storage polymers by heterotrophic bacteria was only observed in the dump fill mode of operation. FISH analyses of the biofilm indicated that ammonia-oxidisers belonged to the beta-subclass Proteobacteria and nitrite-oxidisers were affiliated with the genus Nitrospira.Fundo Europeu de Desenvolvimento Regional (FEDER)Fundação para a Ciência e a Tecnologia (FCT

Time-dependent dual effects of high levels of unconjugated bilirubin on the human blood-brain barrier lining

In neonatal jaundice, high levels of unconjugated bilirubin (UCB) may induce neurological dysfunction (BIND). Recently, it was observed that UCB induces alterations on brain microvasculature, which may facilitate its entrance into the brain, but little is known about the steps involved. To evaluate if UCB damages the integrity of human brain microvascular endothelial cells (HBMECs), we used 50 or 100 μM UCB plus human serum albumin, to mimic the neuropathological conditions where levels of UCB free species correspond to moderate and severe neonatal jaundice, respectively. Our results point to a biphasic response of HBMEC to UCB depending on time of exposure. The early response includes increased number of caveolae and caveolin-1 expression, as well as upregulation of vascular endothelial growth factor (VEGF) and its receptor 2 (VEGFR-2) with no alterations of the paracellular permeability. In contrast, effects by sustained hyperbilirubinemia are the reduction in zonula occludens (ZO)-1 and β-catenin levels and thus of tight junctions (TJ) strands and cell-to-cell contacts. In addition, reduction of the transendothelial electrical resistance (TEER) and increased paracellular permeability are observed, revealing loss of the barrier properties. The 72 h of HBMEC exposure to UCB triggers a cell response to the stressful stimulus evidenced by increased autophagy. In this later condition, the UCB intracellular content and the detachment of both viable and non-viable cells are increased. These findings contribute to understand why the duration of hyperbilirubinemia is considered one of the risk factors of BIND. Indeed, facilitated brain entrance of the free UCB species will favor its parenchymal accumulation and neurological dysfunction

Synthesis and degradation of poly-β-hydroxybutyrate in a sequencing batch biofilm reactor

The aim of this work was the study of poly-β-hydroxybutyrate (PHB) formation and degradation in a sequencing batch biofilm reactor (SBBR). The SBBR was operated in cycles comprising three individual phases: mixed fill, aeration and draw. A synthetic substrate solution with acetate and ammonium was used. PHB was formed during the aeration phase immediately after acetate depletion, and was subsequently consumed for biomass growth, owing to the high oxygen concentration in the reactor. It was observed a combination of suspended and biofilm growth in the SBBR with predominance of the fixed form of biomass (506 Cmmol and 2102 Cmmol, respectively). Maximum PHB fraction of suspended biomass (0.13 Cmol/Cmol) was considerably higher than that of biofilm (0.01 Cmol/Cmol). This may possibly be explained by a combination of two factors: lower mass transfer limitation of acetate and higher fraction of heterotrophs in suspended biomass compared to the ones of biofilm.Fundo Europeu de Desenvolvimento Regional (FEDER) - POCI 2010 (POCI/AMB/61155/2004)Fundação para a Ciência e a Tecnologia (FCT) - PRAXIS XXI BD/19687/9

Biofilm technology : from support design to reactor operation

The aim of this work was to assess the feasibility of a Sequential Batch Biofilm Reactor (SBBR) to perform carbon and nitrogen removal: from support design to reactor operation. The experimental part was conducted in two phases. In the first phase, different supports were tested to select the most suitable one for SBBR operation. In the second phase, the most appropriate support was used in a SBBR to perform carbon and nitrogen removal. The results demonstrate that the support with the highest internal surface area presented a higher biomass accumulation. Time profiles of nitrogen ions and acetate concentration showed the typical behaviour of a SBBR performing carbon and nitrogen removal. Poly-bhydroxybutyrate (PHB) was formed immediately after acetate depletion and was subsequently consumed for biomass growth, owing to the high oxygen concentration in the reactor

Impact of biofilm growth in the microbial community composition of a sequencing batch reactor

Conventional activated sludge wastewater treatment plants (WWTP) for carbon and nutrient removal operate at high sludge retention time and, consequently, at a low food to microorganisms ratio. While the first condition is favourable for nitrifying bacteria growth, an excessive growth of certain species of filamentous bacteria often occurs in the presence of the second one. Interestingly, no problems with excessive growth of filamentous bacteria have been reported for the activated sludge process when combined with biofilm growth more than a decade ago. In this context, the present work aims to compare the microbial community composition of two sequencing batch reactors (SBRs) operating in the presence and in the absence of biofilm growth, and to correlate microbial composition with the performance of the reactors. Two SBRs with a working volume of 1.5 L were operated in parallel with a constant cycle time of 4 h, a volume exchange ratio of 0.5 L/L and a resulting hydraulic retention time of 8 h. The duration of the individual operating phases was: 5 min fill, 225 min aerated, 5 min settle and 5 min draw. During the aerated phase airflow was applied through membrane diffusers, causing the reactor contents including the carrier bed to circulate. The SBRs were operated with synthetic water containing acetate as the only carbon source and ammonium as nitrogen source. One SBR was operated just with suspended biomass while the second one combined suspended biomass with biofilm cultivation. The biofilm was formed on a new type of polyethylene support developed by University of Minho, consisting of hollow, star-shaped, carriers with 17 mm external diameter and a height of 10 mm. The bed formed by these carriers had a specific surface area of 407 m2/m3, an average porosity of 0.74 and occupied 20 % of the reactor volume. Grab samples were taken and analyzed for acetate using a HPLC system. Observation of the filamentous microbial and microfauna communities was accomplished by microscope inspection at 100 to 1000X magnification, in fresh samples and after Gram and Neisser staining. The microbial community of the SBR operating just with suspended growth was dominated by fungi micelar growth, while in the other reactor the communities were clearly more complex. The incorporation of carriers for biofilm growth in the other SBR apparently suppressed the excessive growth of fungi. Differences in the microfaunas community were also observed, the SBR operating just with suspended growth showing clearly a delay in the microfauna succession comparing to the other reactor. Despite this, acetate was completely removed in both SBRs

Social media: friend or foe in the COVID-19 pandemic?

Submitted by Raphael Belchior ([email protected]) on 2020-05-20T16:12:39Z No. of bitstreams: 1 1807-5932-clin-75-e1953.pdf: 128147 bytes, checksum: 10a855d459c314e6c24aed9a73bba53c (MD5)Approved for entry into archive by Raphael Belchior ([email protected]) on 2020-05-20T22:59:59Z (GMT) No. of bitstreams: 1 1807-5932-clin-75-e1953.pdf: 128147 bytes, checksum: 10a855d459c314e6c24aed9a73bba53c (MD5)Made available in DSpace on 2020-05-20T23:00:00Z (GMT). No. of bitstreams: 1 1807-5932-clin-75-e1953.pdf: 128147 bytes, checksum: 10a855d459c314e6c24aed9a73bba53c (MD5) Previous issue date: 2020Montefiore Medical Center. Department of Surgery. The Bronx, NY, USA.Real Hospital Português. Cardiologia. Recife, PE, Brasil.Fundação Oswaldo Cruz. Instituto Aggeu Magalhaes. Departamento de Saúde Coletiva. Recife, PE, Brasil

Integration of lean manufacturing and ergonomics in a metallurgical industry

Striving to improve productivity, industries have used different management approaches, being lean manufacturing the most used over recent years. Lean manufacturing is based on value creation for the customer and elimination of waste that occurs during the production process, while improving working conditions. The incorporation of ergonomic aspects in the workstation design also contributes for the referred objectives, since it will reduce awkward postures or excessive effort during work, leading to better working conditions and increased productivity. The present study highlights, through a case study in four production areas of a metallurgical industry, the benefits of using an integrated operations management approach to improve productivity and ergonomic aspects. Several ergonomic methods, such as Rapid Upper Limb Assessment (RULA), Strain Index (SI), and Rapid Entire Body Assessment (REBA), were chosen to evaluate the ergonomic situation and lean manufacturing tools such as Value Stream Mapping (VSM) and 7 wastes were also used to analyze the systems and increase the productivity by eliminating several wastes. The results of this study show that it is possible, and desirable, to consider both aspects, ergonomic conditions and productivity, during continuous improvement’ implementations. In fact, the improvements reached through the advances in ergonomic conditions can contribute very positively for productivity increasing.info:eu-repo/semantics/publishedVersio

First Report of the Root-Knot Nematode (Meloidogyne javanica) Infecting Hops (Humulus lupulus) in Florida, USA

Humulus lupulus (Cannabaceae), commonly referred to as hops, are perennial, herbaceous climbing plants, native to temperate northern climates. Hops are cultivated for their strobiles or cones, which are often used for flavoring and aroma in food, tea, and beer (Almaguer et al. 2014; Burgess 1964). Because of the high demand for hops from the micro-brewing industry in the Tampa-St. Petersburg area, it has recently been introduced in Florida. The crop grows rapidly in the early spring to late summer. Plants reach a mature height of 18-25 feet in one year and produce cones from mid-summer to early fall (Pearson, 2016). Hop rhizomes were planted in April 2016 at the Gulf Coast Research Station, Wimauma, Hillsborough Co., Florida, USA. In October 2016, several hop plants that exhibited yellowing leaves and stunted growth were uprooted and showed severe root galling (Figs.1;2). Rhizosphere soil samples were collected for nematode extraction and showed high numbers of root-knot nematode second-stage juveniles (J2) (up to 1500 J2/ 200cm3 soil). Heavily galled root samples were sent to the Florida Department of Agriculture and Consumer Services, Division of Plant Industry Nematology Laboratory in Gainesville, FL. Species identification was performed using morphological analyses of females perenal patterns (n=22), selected characters of second-stage juveniles (n=17), and isozyme phenotypes (esterase and malate dehydrogenase) of egg- laying females (n=26) extracted from the roots. Configuration of the perineal patterns, morphometrics of body, stylet and tail length of J2 and the esterase phenotype (EST= J3), which is species-specific and malate phenotype (MDH=N1), are consistente with those reported in the original descrition of M. javanica and many other populations of this nematode species collected in Florida and other countries (Brito et al., 2008; Cofcewick et al., 2005; Carneiro et al., 2004; Jepson, 1987; Esbenshade and Triantaphyllou, 1985). For molecular analyses, DNA was extracted from individual females and mitochondrial DNA was amplified with MORF (5?- ATC GGG GTT TAA TAA TGG G - 3?) and MTHIS (5? - AAA TTC AAT TGA AAT TAA TAG C -3?) primer set (Pagan et al., 2015; Stanton et al., 1997). A fragment of approximately 740 bp was produced, which has been reported for M. incognita and M. javanica found in Florida (Baidoo et al., 2016). To further confirm the species identification we use the speices-specific SCAR primer set Fjav (5 ?- GGT GCG CGA TTG AAC TGA GC - 3?) and Rjav (5? - CAG GCC CTT CAG TGG AAC TAT AC - 3?) (Zijlstra et al., 2000). This primer set yield a fragment of of approximately 670bp, which is identical to that previously reported for M. javanica (Humphreys-Pereira et al., 2017; Baidoo et al., 2016; Zijlstra et al., 2000). Additionally, NADH dehydrogenase subunit 5 gene was amplified using NAD5F2 (5?- TAT TTT TTG TTT GAG ATA TAT TAG - 3?) and NAD5R1 (5?- CGTGAATCTTGATTTTCCATTTTT-3?) primers as described by Janssen et al. (2016). The GenBank accession number of the nad5 gene sequence is MH230176. The obtained the nad5 gene sequence was identical to the reference sequence of M. javanica provided by Janssen et al. (2016). To our knowledge, this is the first report of H. lupulus as a host of the Javanese root-knot nematode (M. javanica) in Florida.Fil: Brito, J. A.. University of Florida; Estados UnidosFil: Subotini, S.A.. University of California; Estados UnidosFil: Desaeger, J.. University of Florida; Estados UnidosFil: Achinelly, Maria Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Qiu, Sai. University of Florida; Estados Unido