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Effects of pesticides and electromagnetic fields on honeybees: a field study using biomarkers
No full textThe effect of pesticide mixtures and electromagnetic fields were evaluated on honeybees in three experimental sites located in northern Italy: a control site far from anthropogenic stress sources, a semi-natural site close to a high voltage electric line and an agricultural site with intensive pesticide treatments. From each experimental site, young workers and foraging bees were taken monthly from May to October and analysed for four enzymatic biomarkers: acetylcholinesterase (AChE), catalase (CAT), glutathione S-transferase (GST) and alkaline phosphatase (AP). Results revealed timeand site-specific effects in respect to control site, confirming the role of biomarkers as diagnostic and early-warning tools for multi-stress sources on honeybees. In the electromagnetic-stress site an effect of an over-activation of all analyzed biomarkers was observed at the end of the season. According to other literature findings, this event was related to a behavioral over-activation in a period in which bees should prepare themselves to overwintering. This finding poses potential problems to winter survival. In the pesticide-stress site, different pesticide-induced responses were identified. We demonstrated in the field that pesticide mixtures, currently used in agriculture, were able to greatly affect biochemical parameters of bees (with both enzymatic under- and
over-activations)
Improved antifouling performance of polyester thin film nanofiber composite membranes prepared by interfacial polymerization
No full textStudy of a hybrid photovoltaic-photochemical technology for meeting the needs of safe drinking water and electricity in developing countries: First field trial in rural Mexico
No full textExploring microcystin-degrading bacteria thriving on recycled membranes during a cyanobacterial bloom
No full textMicrocystins (MC) are highly toxic secondary metabolites produced by cyanobacterial blooms in many freshwater ecosystems used for recreational and drinking water purposes. So far, biological processes remain to be optimized for an efficient cyanotoxin removal, and new approaches are necessary to compete with physical-chemical treatments. In previous studies we provided a new concept of membrane biofilm reactor made of recycled material, in which a single MC-degrading bacterial strain was inoculated. The present study evaluates the capacity of bacterial consortia associated with freshwater cyanobacterial blooms to form biofilms on recycled membranes and remove MC. Three different discarded reverse osmosis (RO) membranes, previously used in desalination plants after treating brackish water (BWd), seawater (SWd) and brackish water but transformed into nanofiltration (BWt-NF), were exposed to a cyanobacterial bloom in San Juan reservoir (central Spain). Results showed that the three recycled membranes developed a bacterial community with MC removal capacity. Little differences in bacterial coverage and MC removal efficiency between membranes were observed after their exposure in the reservoir. High-throughput sequencing of 16S rRNA gene analysis showed similar bacterial community composition at the phylum level but dissimilar at the order level between the three membranes. This suggests possible surface selectivity on the attached bacterial community. The mlr- candidates such as Burkholderiales and Methylophilales were highly abundant in BWt-NF and BWd, respectively, while mlr+ candidates (e.g. Sphingomonadales) were low abundant in all membranes. Analysis of mlrA and mlrB genes used as markers for MC degradation following mlr-pathway confirmed the presence of this pathway in all membranes. These results suggest the co-existence of both genotypes in membrane-attached native biofilms. Therefore, this study confirms that recycled membranes are suitable support for many MC-degrading bacteria, thus giving value to discarded membranes for eco-friendly and low-cost biological filters
Simultaneous characterization of porous and non-porous electrodes in microbial electrochemical systems
No full textAdequate electrochemical characterization of electrode material/biofilms is crucial for a comprehensive understanding and comparative performance of bioelectrochemical systems (BES). However, their responses are greatly affected by the metabolic activity and growth of these living entities and/or the interference of electrode wiring that can act as an electroactive surface for growth or constitute a source of contamination by corrosion. This restricts the meaningful comparison of the performance of distinct electrode materials in BES. This work describes a methodology for simultaneous electrochemical control and measurement of the microbial response on different electrode materials under the same physicochemical and biological conditions. The method is based on the use of a single channel potentiostat and one counter and reference electrodes to simultaneously polarize several electrode materials in a sole bioelectrochemical cell. Furthermore, various strategies to minimize wiring corrosion are proposed. The proposed methodology, then, will enable a more rigorous characterization of microbial electrochemical responses for comparisons purposes
Optimization of Recycled-Membrane Biofilm Reactor (R-MBfR) as a sustainable biological treatment for microcystins removal
No full textThis work aims to investigate optimization while running a Recycled-Membrane Biofilm Reactor as a sustainable biological treatment for microcystins (MC) removal. For this purpose, coupons from an end-of-life seawater reverse osmosis (RO) membrane module were extracted and conditioned. The MC-degrading biofilm formation on this recycled membrane surface was carried out in a simulator cell on the laboratory scale to study the influence of air supply in this step. Firstly, the main results obtained in this work are related to the biofilm formation. Confocal laser scanning microscope (CLSM) demonstrated that air supply provide a higher biomass, maximum thickness and lower roughness coefficient. Secondly, the air supply also stimulated the MC removal by shortening the lag phase and increasing the MC degradation rate. Finally, the developed biofilm with air supply also was able to efficiently remove MC from two different types of polluted water, surface natural water (SNW) and synthetic reclaimed water (SRW). These results support the R-MBfR technology for treating MC-polluted water that could be used for different application, especially in nutrient-rich water. Therefore, this study addresses the lack of sustainable technologies for water treatment, while opening an alternative in sustainable solid waste management under a circular economy approach
Flood Risk Analysis and Assessment, Applications and Uncertainties: A Bibliometric Review
No full textStudies looking at flood risk analysis and assessment (FRA) reviews are not customary, and they usually approach to methodological and spatial scale issues, uncertainty, mapping or economic damage topics. However, most of these reviews provide a snapshot of the scientific state of the art of FRA that shows only a partial view, focused on a limited number of selected methods and approaches. In this paper, we apply a bibliometric analysis using the Web of Science (WoS) database to assess the historic evolution and future prospects (emerging fields of application) of FRA. The scientific production of FRA has increased considerably in the past decade. At the beginning, US researchers dominated the field, but now they have been overtaken by the Chinese. The Netherlands and Germany may be highlighted for their more complete analyses and assessments (e.g., including an uncertainty analysis of FRA results), and this can be related to the presence of competitive research groups focused on FRA. Regarding FRA fields of application, resilience analysis shows some growth in recent years while land planning, risk perception and risk warning show a slight decrease in the number of papers published. Global warming appears to dominate part of future FRA production, which affects both fluvial and coastal floods. This, together with the improvement of economic evaluation and psycho-social analysis, appear to be the main trends for the future evolution of FRA. Finally, we cannot ignore the increase in analysis using big data analysis, machine learning techniques, and remote sensing data (particularly in the case of UAV sensors data)
Opinion on the potential for anaerobic biodegradability in marine and freshwater of Linear Alkylbenzene Sulphonates(LAS)
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