Renewables-driven membrane distillation for drinking water purification: Main Ethiopian Rift Valley case study

[ES] El flúor está presente en todo tipo de recursos hídricos, pero consumir agua con niveles más allá de la actual pauta de la Organización Mundial de la Salud, 1.5mg/L, puede ser muy dañinos para la salud de las personas. Debido a la naturaleza volcánica de las rocas en el Valle del Rift de Etiopía, el agua subterránea está contaminada con flúor, y los estudios incluso han registrado niveles de hasta 26 mg/l. Estos niveles excesivos están afectando a más de 14 millones de mujeres y niños de Etiopía. Proporcionar a esa población agua segura y limpia podría ayudar a alcanzar el Objetivo de Desarrollo Sostenible 6 (Garantizar la disponibilidad y la gestión sostenible del agua y el saneamiento para todos) de la ONU. Los sistemas de destilación de membrana han sido probados y han demostrado ser efectivos para eliminar el flúor incluso con agua con concentraciones altas de flúor (500 mg/L). La destilación por membrana es un sistema impulsado por calor que funciona con temperaturas por debajo de los 100ºC. Fuentes de energía renovables como geotermia, solar o biomasa pueden usarse para proporcionar ese calor. Este informe evalúa tecno-económicamente diferentes tecnologías usando TRNSYS: colectores planos, colectores de tubos de vacío y biogás a partir de estiércol animal, como fuente de calor para la unidad de destilación de membrana. El tamaño de las instalaciones hipotéticas se optimizó para cubrir la demanda de 30 hogares. Se calcularon varios indicadores para comparar las diferentes tecnologías: consumo térmico específico, producción de agua y la eficiencia de los sistemas. Se consideraron los costes de inversión y los costes de operación y mantenimiento para calcular los costes totales de la instalación y el período de amortización de las diferentes instalaciones. Los resultados muestran que la mejor opción tecno-económica para instalar es un modelo híbrido que combina colectores de tubos de vacío y una unidad de producción de calor y electricidad alimentada con biogás. Ésta puede satisfacer no solo la demanda con una unidad de destilación de membrana sino también suministrar electricidad y biogás para cocinar. Sin embargo, dependiendo de la ubicación específica, la disponibilidad de radiación solar y el estiércol puede variar y, en consecuencia, la mejor opción cambiará. En caso de que la existencia de ganado sea limitada, tres unidades de destilación de membrana junto con 85m2 de colectores de tubo evacuados pueden cubrir la demanda. Si la disponibilidad de sol es limitada, se puede considerar dos unidades de membrana con una unidad de biogás autónoma. Los colectores planos nunca son la mejor opción, ya que requieren el coste de inversión más alto. Sin embargo, la existencia de fabricantes locales puede disminuir los costes.[EN] Fluoride is present in all type of water sources, but levels beyond the current World Health Organization guideline of 1.5mg/L can be very harmful for people s health. Due to the volcanic nature of rocks in the Ethiopian Rift Valley, groundwater is contaminated with fluoride, and studies have even recorded levels up to 26mg/L. These excessive levels are affecting more than 14 million women and children from Ethiopia. Providing that population with safe and clean water could help to achieve the Sustainable Development Goal 6 (Ensure availability and sustainable management of water and sanitation for all) from the UN. Membrane distillation systems have been tested and showed to be effective in removing fluoride even at high feed levels (500 mg/L). Membrane distillation is a heat driven system that works under feed water temperatures below 100ºC. Renewable energy sources such as geothermal, solar or biomass can be used to provide that heat. This report evaluates techno-economically different technologies using TRNSYS: flat plate collectors, evacuated tube collectors and biogas from animal dung, as heat source for the membrane distillation unit. The size of the hypothetical installations was optimized to cover the demand of 30 households. Several indicators were calculated to compare the different technologies: specific thermal consumption, water production and the efficiency of the systems. Investment and operation and management costs were considered to calculate the total costs and payback period of the different installations. The results show that the best techno-economic option to install is a hybrid model that combines a combined heat and power unit powered by biogas and evacuated tube collectors, as it can meet not only the demand with one membrane distillation unit but also supply electricity and biogas for cooking. However, depending on the specific location, the availability of solar radiation and manure can vary, and consequently the best option will change. In case the existence of livestock is limited, three membrane distillation units coupled with 85m2 of evacuated tube collectors can cover the demand. If the availability of sun is limited one membrane unit couple with a standalone biogas unit can be considered. Flat plate collectors are never the best option, as they require the biggest investment cost. Nevertheless, the existence of local manufacturers can decrease the costs.Gabaldón Moreno, A. (2018). Renewables-driven membrane distillation for drinking water purification: Main Ethiopian Rift Valley case study. Universitat Politècnica de València. http://hdl.handle.net/10251/144474TFG

How to Achieve Positive Energy Districts for Sustainable Cities: A Proposed Calculation Methodology

In this paper, a methodology for calculating the energy balance at the district level and energy performance of those districts aspiring to become a Positive Energy District (PED) is proposed. PEDs are understood as districts that achieve a positive energy balance on an annual basis by means of exporting more energy than is consumed within their limits. The main issue to standardize the concept, besides which characteristics should be considered, is that current standards to calculate an energy balance are not applied at the district level. This paper reviews the current standards and adapts them to propose an energy balance calculation methodology. Calculation of an energy balance at the district level is complex since it includes several parameters, such as which loads (or elements) should be included, which renewable energy technologies should be considered on-site production, and which primary energy factors should be used. The proposed methodology is thought to help cities at the design stage of a district and to evaluate its annual energy balance. The methodology is performed in eight steps, and all the needed assumptions that affect the calculation of the annual energy balance are discussed in each stepThis project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 824418 (MAKING-CITY)

Study of the atenolol degradation using a Nb/BDD electrode in a filter-press reactor

[EN] The present paper deals with the atenolol (ATL) degradation by advanced anodic oxidation using a boron-doped diamond anode supported on niobium (Nb/BDD). Cyclic voltammetry performed on this electrode revealed that it presents a high quality (diamond-sp3/sp2-carbon ratio), high potential for OER and that ATL can be oxidized directly and/or indirectly by the electrogenerated oxidants, such as hydroxyl radicals, persulfate ions and sulfate radicals. Electrolysis experiments demonstrated that ATL degradation and mineralization follow a mixed (first and zero) order kinetics depending on the applied current density. At high applied current densities, the amount of OH radicals is very high and the overall reaction is limited by the transport of ATL (pseudo first-order kinetics) whereas for low applied current densities, the rate of OH radicals generation at the anode is slower than the rate of arrival of ATL molecules (pseudo-zero order kinetics). Estimated values of kzero and kfirst based on the assumption of pseudo-zero or pseudo-first order kinetics were carried oud as a function of the supporting electrolyte concentration, indicating that both parameters increased with its concentration due the higher production of sulfate reactive species that play an important role in degradation. Finally, MCE increased with the decrease of current density, due to the lower amount of OH present in solution, since this species could be rapidly wasted in parasitic reactions; and the increase of sulfate concentration due to the more efficient production of persulfate.The authors thank the financial support from the Ministerio de Economía y Competitividad (Spain) under projects CTQ2015-65202-C2-1-R and RTI2018-101341-B-C21, co-financed with FEDER funds. The authors thank to FAPERGS, CAPES, FINEP and CNPQ.Heberle, ANA.; García Gabaldón, M.; Ortega, EM.; Bernardes, AM.; Pérez-Herranz, V. (2019). Study of the atenolol degradation using a Nb/BDD electrode in a filter-press reactor. Chemosphere. 236:1-8. https://doi.org/10.1016/j.chemosphere.2019.07.049S1823

Genome analysis of five recently described species of the CUG-Ser clade uncovers Candida theae as a new hybrid lineage with pathogenic potential in the Candida parapsilosis species complex

Candida parapsilosis species complex comprises three important pathogenic species: Candida parapsilosis sensu stricto, Candida orthopsilosis and Candida metapsilosis. The majority of C. orthopsilosis and all C. metapsilosis isolates sequenced thus far are hybrids, and most of the parental lineages remain unidentified. This led to the hypothesis that hybrids with pathogenic potential were formed by the hybridization of non-pathogenic lineages that thrive in the environment. In a search for the missing hybrid parentals, and aiming to get a better understanding of the evolution of the species complex, we sequenced, assembled and analysed the genome of five close relatives isolated from the environment: Candida jiufengensis, Candida pseudojiufengensis, Candida oxycetoniae, Candida margitis and Candida theae. We found that the linear conformation of mitochondrial genomes in Candida species emerged multiple times independently. Furthermore, our analyses discarded the possible involvement of these species in the mentioned hybridizations, but identified C. theae as an additional hybrid in the species complex. Importantly, C. theae was recently associated with a case of infection, and we also uncovered the hybrid nature of this clinical isolate. Altogether, our results reinforce the hypothesis that hybridization is widespread among Candida species, and potentially contributes to the emergence of lineages with opportunistic pathogenic behaviour.This work received funding from the European Union’s Horizon 2020 Research and Innovation Program under the Marie Skłodowska-Curie Grant Agreement No. H2020-MSCA-ITN-2014-642095. T.G. group also acknowledges support from the Spanish Ministry of Science and Innovation for grant PGC2018-099921-B-I00, cofounded by European Regional Development Fund (ERDF); from the Catalan Research Agency (AGAUR) SGR423; from the European Union’s Horizon 2020 research and innovation programme (ERC-2016-724173); from the Gordon and Betty Moore Foundation (Grant GBMF9742) and from the Instituto de Salud Carlos III (INB Grant PT17/0009/0023—ISCIII-SGEFI/ERDF). J.N. group was supported by the Slovak Research and Development Agency (APVV-18-0239, APVV-20-0166) and the Scientific Grant Agency of the Ministry of Education, Science, Research and Sport of the Slovak Republic (VEGA 1/0027/19).Peer ReviewedPostprint (published version

Transcriptome and proteome profiling reveals complex adaptations of Candida parapsilosis cells assimilating hydroxyaromatic carbon sources

Many fungal species utilize hydroxyderivatives of benzene and benzoic acid as carbon sources. The yeast Candida parapsilosis metabolizes these compounds via the 3-oxoadi- pate and gentisate pathways, whose components are encoded by two metabolic gene clusters. In this study, we determine the chromosome level assembly of the C. parapsilosis strain CLIB214 and use it for transcriptomic and proteomic investigation of cells cultivated on hydroxyaromatic substrates. We demonstrate that the genes coding for enzymes and plasma membrane transporters involved in the 3-oxoadipate and gentisate pathways are highly upregulated and their expression is controlled in a substrate-specific manner. However, regulatory proteins involved in this process are not known. Using the knockout mutants, we show that putative transcriptional factors encoded by the genes OTF1 and GTF1 located within these gene clusters function as transcriptional activators of the 3-oxoa-dipate and gentisate pathway, respectively. We also show that the activation of both pathways is accompanied by upregulation of genes for the enzymes involved in β-oxidation of fatty acids, glyoxylate cycle, amino acid metabolism, and peroxisome biogenesis. Transcriptome and proteome profiles of the cells grown on 4-hydroxybenzoate and 3-hydroxybenzo- ate, which are metabolized via the 3-oxoadipate and gentisate pathway, respectively, reflect their different connection to central metabolism. Yet we find that the expression profiles differ also in the cells assimilating 4-hydroxybenzoate and hydroquinone, which are both metabolized in the same pathway. This finding is consistent with the phenotype of the Otf1p-lacking mutant, which exhibits impaired growth on hydroxybenzoates, but still utilizes hydroxybenzenes, thus indicating that additional, yet unidentified transcription factor could be involved in the 3-oxoadipate pathway regulation. Moreover, we propose that bicarbonate ions resulting from decarboxylation of hydroxybenzoates also contribute to differences in the cell responses to hydroxybenzoates and hydroxybenzenes. Finally, our phylogenetic analysis highlights evolutionary paths leading to metabolic adaptations of yeast cells assimilating hydroxyaromatic substrates

Evolution of selenophosphate synthetases: emergence and relocation of function through independent duplications and recurrent subfunctionalization

Selenoproteins are proteins that incorporate selenocysteine (Sec), a nonstandard amino acid encoded by UGA, normally a stop codon. Sec synthesis requires the enzyme Selenophosphate synthetase (SPS or SelD), conserved in all prokaryotic and eukaryotic genomes encoding selenoproteins. Here, we study the evolutionary history of SPS genes, providing a map of selenoprotein function spanning the whole tree of life. SPS is itself a selenoprotein in many species, although functionally equivalent homologs that replace the Sec site with cysteine (Cys) are common. Many metazoans, however, possess SPS genes with substitutions other than Sec or Cys (collectively referred to as SPS1). Using complementation assays in fly mutants, we show that these genes share a common function, which appears to be distinct from the synthesis of selenophosphate carried out by the Sec- and Cys- SPS genes (termed SPS2), and unrelated to Sec synthesis. We show here that SPS1 genes originated through a number of independent gene duplications from an ancestral metazoan selenoprotein SPS2 gene that most likely already carried the SPS1 function. Thus, in SPS genes, parallel duplications and subsequent convergent subfunctionalization have resulted in the segregation to different loci of functions initially carried by a single gene. This evolutionary history constitutes a remarkable example of emergence and evolution of gene function, which we have been able to trace thanks to the singular features of SPS genes, wherein the amino acid at a single site determines unequivocally protein function and is intertwined to the evolutionary fate of the entire selenoproteome

How genomics can help biodiversity conservation

The availability of public genomic resources can greatly assist biodiversity assessment, conservation, and restoration efforts by providing evidence for scientifically informed management decisions. Here we survey the main approaches and applications in biodiversity and conservation genomics, considering practical factors, such as cost, time, prerequisite skills, and current shortcomings of applications. Most approaches perform best in combination with reference genomes from the target species or closely related species. We review case studies to illustrate how reference genomes can facilitate biodiversity research and conservation across the tree of life. We conclude that the time is ripe to view reference genomes as fundamental resources and to integrate their use as a best practice in conservation genomics.info:eu-repo/semantics/publishedVersio

The era of reference genomes in conservation genomics

Progress in genome sequencing now enables the large-scale generation of reference genomes. Various international initiatives aim to generate reference genomes representing global biodiversity. These genomes provide unique insights into genomic diversity and architecture, thereby enabling comprehensive analyses of population and functional genomics, and are expected to revolutionize conservation genomics

The era of reference genomes in conservation genomics

info:eu-repo/semantics/publishedVersio

The era of reference genomes in conservation genomics

Progress in genome sequencing now enables the large-scale generation of reference genomes. Various international initiatives aim to generate reference genomes representing global biodiversity. These genomes provide unique insights into genomic diversity and architecture, thereby enabling comprehensive analyses of population and functional genomics, and are expected to revolutionize conservation genomics