Efficiently combining water reuse and desalination through Forward Osmosis-Reverse Osmosis (FO-RO) hybrids: a critical review

Forward osmosis (FO) is a promising membrane technology to combine seawater desalination and water reuse. More specifically, in a FO-reverse osmosis (RO) hybrid process, high quality water recovered from the wastewater stream is used to dilute seawater before RO treatment. As such, lower desalination energy needs and/or water augmentation can be obtained while delivering safe water for direct potable reuse thanks to the double dense membrane barrier protection. Typically, FO-RO hybrid can be a credible alternative to new desalination facilities or to implementation of stand-alone water reuse schemes. However, apart from the societal (public perception of water reuse for potable application) and water management challenges (proximity of wastewater and desalination plants), FO-RO hybrid has to overcome technical limitation such as low FO permeation flux to become economically attractive. Recent developments (i.e., improved FO membranes, use of pressure assisted osmosis, PAO) demonstrated significant improvement in water flux. However, flux improvement is associated with drawbacks, such as increased fouling behaviour, lower rejection of trace organic compounds (TrOCs) in PAO operation, and limitation in FO membrane mechanical resistance, which need to be better considered. To support successful implementation of FO-RO hybrid in the industry, further work is required regarding up-scaling to apprehend full-scale challenges in term of mass transfer limitation, pressure drop, fouling and cleaning strategies on a module scale. In addition, refined economics assessment is expected to integrate fouling and other maintenance costs/savings of the FO/PAO-RO hybrid systems, as well as cost savings from any treatment step avoided in the water recycling

Practical considerations for operability of an 8″ spiral wound forward osmosis module: Hydrodynamics, fouling behaviour and cleaning strategy

© 2016 Elsevier B.V. A better understanding of large spiral wound forward osmosis (SW FO) module operation is needed to provide practical insight for a full-scale FO practical implementation desalination plant. Therefore, this study investigated two different 8″ SW FO modules (i.e. cellulose tri acetate, CTA and thin film composite, TFC) in terms of hydrodynamics, operating pressure, water and solute fluxes, fouling behaviour and cleaning strategy. For both modules, a significantly lower flow rate was required in the draw channel than in the feed channel due to important pressure-drop in the draw channel and was a particularly critical operating challenge in the CTA module when permeate spacers are used. Under FO and pressure assisted osmosis (PAO, up to 2.5 bar) operations, the TFC module featured higher water flux and lower reverse salt flux than the CTA module. For both modules, fouling tests demonstrated that feed inlet pressure was more sensitive to foulant deposition than the flux, thus confirming that FO fouling deposition occurs in the feed channel rather than on the membrane surface. Osmotic backwash combined with physical cleaning used in this study confirmed to be effective and adapted to large-scale FO module operation

The drivers of the success of Spanish Canoeing: an analysis of the efficiency of regional federations

Even though canoeing is not a particularly popular sport in Spain, it is one of the Olympic disciplines that has brought much success to the Spanish medal table. This high performance of Spanish canoeing could be attributed to the work of the clubs and regional federations (FFAA) which can optimise the scarce resources available to them, most of which come from public transfers. This study measures the efficiency of the Spanish autonomous canoeing federations (FFAAP) during the 2013-2016 Olympic cycle using the Data Envelopment Analysis (DEA) technique and the Malmquist index. A second analysis tries to identify the key factors that lead to the efficiency of the federations. The results show that, despite the significant differences between FFAAs, there is no single way to reach efficiency. In general, the availability of resources increases the chances of achieving results, while coaches and internal competition contribute to optimising the performance of available resources. © 2022 Federacion Espanola de Docentes de Educacion Fisica. All rights reserved

Looking beyond forest cover: an analysis of landscape-scale predictors of forest degradation in the Brazilian Amazon.

While forest degradation rates and extent exceed deforestation in the Brazilian Amazon, less attention is given to the factors controlling its spatial distribution. No quantified correlation exists between changes of forest structure due to anthropogenic disturbances and dynamics of land use and cover change occurring at broader spatial levels. This study examines the influence of multi-scale landscape structure factors (i.e. spatial composition, configuration and dynamic of land use/cover) on primary forest's aboveground biomass (AGB), spanning from low to highly degraded, in Paragominas municipality (Pará state). We used random forest models to identify the most important landscape predictors of degradation and clustering methods to analyze their distribution and interactions. We found that 58% of the variance of AGB could be explained by metrics reflecting land use practices and agricultural dynamics around primary forest patches and that their spatial patterns were not randomly distributed. Forest degradation is mainly driven by fragmentation effects resulting from old deforestation and colonization events linked with cropland expansion (e.g. soybean and maize) coupled with high accessibility to market. To a lesser extent, degradation is driven by recent and ongoing (1985?2015) deforestation and fragmentation in slash-and-burn agricultural areas, characterized by heterogeneous mosaics of pastures and fallow lands combined with high use of fire. Our findings highlight the potential of landscape-level framework and remotely sensed land cover data for a thorough understanding of the distribution of forest degradation across human-modified landscapes. Addressing these spatial determinants by looking at agricultural dynamics beyond forest cover is necessary to improve forest management which has major implications for biodiversity, carbon and other ecosystem services

Role of CAP350 in Centriolar Tubule Stability and Centriole Assembly

BACKGROUND: Centrioles are microtubule-based cylindrical structures composed of nine triplet tubules and are required for the formation of the centrosome, flagella and cilia. Despite theirs importance, centriole biogenesis is poorly understood. Centrosome duplication is initiated at the G1/S transition by the sequential recruitment of a set of conserved proteins under the control of the kinase Plk4. Subsequently, the procentriole is assembled by the polymerization of centriolar tubules via an unknown mechanism involving several tubulin paralogs. METHODOLOGY/PRINCIPAL FINDINGS: Here, we developed a cellular assay to study centrosome duplication and procentriole stability based on its sensitivity to the microtubule-depolymerizing drug nocodazole. By using RNA interference experiments, we show that the stability of growing procentrioles is regulated by the microtubule-stabilizing protein CAP350, independently of hSAS-6 and CPAP which initiate procentriole growth. Furthermore, our analysis reveals the critical role of centriolar tubule stability for an efficient procentriole growth. CONCLUSIONS/SIGNIFICANCE: CAP350 belongs to a new class of proteins which associate and stabilize centriolar tubules to control centriole duplication

Pattern of lateral neck metastases in N0 papillary thyroid carcinoma

<p>Abstract</p> <p>Background</p> <p>Indication and extent of lateral prophylactic neck dissection (PLND) in papillary thyroid carcinoma (PTC) is very controversial.</p> <p>Methods</p> <p>We retrospectively analysed 131 patients who underwent thyroidectomy and prophylactic lateral neck dissection from level II to V for PTC.</p> <p>Results</p> <p>140 PLND were performed. The occult lymph node metastases (OLNM) overall rate was 18.6%. The incidence of node involvement was 10% at level III and 6.4% at level IIa. Level IV and level Vb were both concerned by 5.7% OLNM. Only 2.9% of level IIb contained OLNM. None of the level Va ND revealed OLNM.</p> <p>Conclusions</p> <p>OLNM from PTC occurs commonly in level IIa, III, IV and Vb. Incidence in other levels is low. For surgeons that usually perform PLND, we believe that a selective neck dissection of levels IIa, III, IV and Vb in N0 neck PTC is sufficient for the clearance of occult metastases.</p

Performance of industrial scale hollow-fibre membranes in a submerged anaerobic MBR (HF-SAnMBR) system at mesophilic and psychrophilic conditions

The aim of this work was to evaluate the effect of temperature on the performance of industrial hollow-fibre (HF) membranes treating urban wastewater in a submerged anaerobic MBR system (SAnMBR). To this end, a demonstration plant with two commercial HF ultrafiltration membrane modules (PURON®, Koch Membrane Systems, PUR-PSH31) was operated at 20, 25 and 33 °C. The mixed liquor total solid (MLTS) level was a key factor affecting membrane permeability (K). K was higher under psychrophilic than mesophilic conditions when operating at similar transmembrane fluxes and MLTS, because the biomass activity of the psychrophilic mixed liquor was lower than the mesophilic mixed liquor. Thus, lower extracellular polymeric substances (EPSs) and soluble microbial products (SMPs) levels were observed at psychrophilic conditions, which affected not only the three-dimensional floc matrix, but also the fouling propensity. However, no chemical cleaning was needed during the experimental period (almost 1 year) because no irreversible fouling problems were detected.This research work has been supported by the Spanish Research Foundation (CICYT Projects CTM2008-06809-C02-01 and CTM2008-06809-C02-02, and MICINN FPI Grant BES-2009-023712) and Generalitat Valenciana (Projects GVA-ACOMP2010/130 and GVA-ACOMP2011/182), which are gratefully acknowledged.Robles Martínez, Á.; Ruano García, MV.; Ribes Bertomeu, J.; Ferrer, J. (2013). Performance of industrial scale hollow-fibre membranes in a submerged anaerobic MBR (HF-SAnMBR) system at mesophilic and psychrophilic conditions. Separation and Purification Technology. (104):290-296. https://doi.org/10.1016/j.seppur.2012.12.004S29029610

A filtration model applied to submerged anaerobic MBRs (SAnMBRs)

The aim of this study was to develop a model able to correctly reproduce the filtration process of submerged anaerobic MBRs (SAnMBRs). The proposed model was calibrated and validated in a SAnMBR demonstration plant fitted with industrial-scale hollow-fibre membranes. Three suspended components were contemplated in the model: total solids concentration; dry mass of cake on the membrane surface; and dry mass of irreversible fouling on the membrane surface. The model addressed the following physical processes: the build-up and compression of the cake layer during filtration; cake layer removal using biogas sparging to scour the membrane; cake layer removal during back-flushing; and the consolidation of irreversible fouling. The short- and long-term validation of the model resulted in correlation coefficients (R-2) of 0.962 and 0.929, respectively.This research has been supported by the Spanish Ministry of Economy and Competitiveness (MINECO Project CTM2011-28595-C02-01/02) jointly with the European Regional Development Fund (ERDF), which are gratefully acknowledged.Robles Martínez, Á.; Ruano García, MV.; Ribes Bertomeu, J.; Seco Torrecillas, A.; Ferrer, J. (2013). A filtration model applied to submerged anaerobic MBRs (SAnMBRs). Journal of Membrane Science. (444):139-147. https://doi.org/10.1016/j.memsci.2013.05.021S13914744