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Reconciling monitoring and modeling: An appraisal of river monitoring networks based on a spatial autocorrelation approach - emerging pollutants in the Danube River as a case study
No full textRivers extend in space and time under the influence of their catchment area. Our perception largely relies on discrete spatial and temporal observations carried out at certain sites located throughout the catchment (monitoring networks, MN). However, MNs are constrained by (a) the distribution of sampling sites, (b) the dynamics of the variable considered and (c) the river hydrological conditions. In this study, all three aspects were captured and quantified by applying a spatial autocorrelation modeling approach. We exemplarily studied its application to 235 emerging contaminants (pesticides, pharmaceuticals, and personal care products [PPCP], industrial and miscellaneous) measured at 55 sampling sites in the Danube River. 22 out of the 235 compounds monitored were present at all sites and 125 were found in at least 50%.We first calculated the Moran Index (MI) to characterize the spatial autocorrelation of the compound set. 59 compounds showed MI ≤ 0, which can be interpreted as ‘no spatial correlation’. Next, spatial autocorrelation models were set for each compound. From the autocorrelation parameter ρ, catchment average correlation lengths were derived for each compound. MN optimality was examined and compounds were classified into three groups: (a) those with ρ ≤ 0 [25%]; (b) those with ρ > 0 and correl. length 0 and correl. length > average distance between consecutive sites [73%]. The MN was considered optimal only for the latter class. Networks with the larger average distance between consecutive sites resulted in a decreasing number of optimally monitored compounds. Furthermore, neighbors vs. local relative contributions were quantified based on the spatial autocorrelation model for all the measured compounds. The results of this study show how autocorrelation models can aid water managers to improve the design of river MNs, which are a key aspect of the Water Framework Directive
Proposed EU minimum quality requirements for water reuse in agricultural irrigation and aquifer recharge: SCHEER scientific advice
No full textThis manuscript summarizes the opinion of the Scientific
Committee on Health, Environmental and Emerging Risks
(SCHEER) on the report prepared by the European Commission
Joint Research Centre entitled “Proposed EU minimum
quality requirements for water reuse in agricultural irrigation and
aquifer recharge” (draft V.3.3, February 2017). The SCHEER
concludes that, while the methodology chosen is appropriate
and the report considers many important elements, the document
is deficient in key details. In particular the report inadequately
addresses (i) contaminants of emerging concern, (ii)
antibiotic resistance spread through urban wastewater treatment
plants’ effluents, and (iii) possible risks associated with
disinfection and/or advanced treatment of urban wastewater
(e.g. formation of disinfection by products and related toxicity).
Therefore, the SCHEER is of the opinion that the minimum
quality requirements proposed provide insufficient protection
both to environmental and human health. The SCHEER supports
the case-by-case approach proposed, but recommends
that common criteria be defined for the development of case-bycase
assessments, in order to ensure comparable minimum
quality requirements across EU Member States
In vivo assessment of the hepatotoxicity of a new Nostoc isolate from the Nile River: Nostoc sp. strain NRI
No full textNostoc sp. is one of the most widely distributed cyanobacterial genera that produce potentially protein phosphatase (PP) inhibitor; microcystins (MCs). MCs have posed a worldwide concern due to predominant hepatotoxicity to human health. We have previously isolated a Nostoc strain (NR1) from the Nile River (the main water supply in Egypt) and this strain exerted production of rare and highly toxic MC; demethylated microcystin-LR. There is no data concerning risk factors of liver diseases for human and animal exposure to NR1-contaminated drinking water yet. It is thus important to evaluate acute (LD50 dose), subacute (0.01% and 10% of LD50 dose) and subchronic (0.01% and 10% of LD50 dose) hepatotoxicity's NR1 extract using experimental mice. Mice groups, who orally received 0.01% LD50, represented a permissible concentration of the World Health Organization (WHO) for MC in drinking water. Several parameters were detected, including hepatotoxicity (i.e. PP activity, liver function, oxidative stress markers and DNA fragmentation), pro-inflammatory cytokine (TNF-alpha) and liver histopathology. Our results demonstrated LD50 of NR1 extract was at 15,350 mg/kg body weight and caused hepatotoxicity that attributed to PP inhibition and a significant increase of hepatic damage biomarkers with lipid accumulation. Moreover, NR1 extract induced hepatic oxidative damage that may have led to DNA fragmentation and production of TNF-alpha. As demonstrated from the histopathological study, NR1 extract caused a severe collapse of cytoskeleton with subsequent focal degeneration of hepatocytes, necroinflammation and steatosis. The grade of hepatotoxicity in subacute (10% of LD50) group was higher than that in the subchronic (10% of LD50 and 0.01% of LD50, WHOch, respectively) groups. No significant hepatotoxicity was detectable for subacute (0.01% of LD50, WHOac) group. NR1 is therefore considered as one of the harmful and life-threatening cyanobacteria for Egyptian people being exposed to dose above WHO guideline. Thus, biological indicators and thresholds for water treatment are extremely needed
AQUACROSS Deliverable 9.2. Case study 5 report: Improving integrated management of Natura 2000 sites in the Ria de Aveiro Natura 2000 site, from catchment to coast, PortugaL European Union’s Horizon 2020 Framework Programme for Research and Innovation Grant Agreement No. 642317. Technical Report. European Union (H2020 FP Grant Agreement)-AQUACROSS
No full textDiseño de itinerarios de paisaje en la Sierra de Espadán-Río Mijares: puesta en valor y difusión de los recursos paisajísticos locales mediante cartografía web
No full text
Geobacter dominates the inner layers of a stratified biofilm on a fluidized anode during brewery wastewater treatment
No full textIn this study, we designed a microbial electrochemical fluidized bed reactor (ME-FBR), with an electroconductive anodic bed made of activated carbon particles for treating a brewery wastewater. Under a batch operating mode, acetate and propionate consumption rates were 13-fold and 2.4-fold higher, respectively, when the fluidized anode was polarized (0.2 V) with respect to open circuit conditions. Operating in a continuous mode, this system could effectively treat the brewery effluent at organic loading rates (OLR) over 1.7 kg m-3NRV d-1 and with removal efficiencies of 95 ± 1.4% (hydraulic retention time of 1 day and an influent of 1.7 g-COD L-1). The coulombic efficiency values highly depended upon the OLR applied, and varied from a 56 ± 15% to 10 ± 1%. Fluorescence in situ hybridization (FISH) analysis revealed a relative high abundance of Geobacter species (ca. 20%), and clearly showed a natural microbial stratification. Interestingly, the Geobacter cluster was highly enriched in the innermost layers of the biofilm (thickness of 10 μm), which were in contact with the electroconductive particles of bed, whereas the rest of bacteria were located in the outermost layers. To our knowledge, this is the first time that such a clear microbial stratification has been observed on an anode-respiring biofilm. Our results revealed the relevant role of Geobacter in switching between the electrode and other microbial communities performing metabolic reactions in the outermost environment of the biofilm
On the actual anode area that contributes to the current density produced by electroactive biofilms
No full textEven with an increasing interest in scaling-up Microbial Electrochemical Technologies (MET), it is still common to focus on their “fundamentals”. An important example is the production of current density (jmax) by microbial anodes in a three-electrode arrangement (3 EA) configuration, e.g.: a graphite plate of well-defined projected (or geometric) surface area (PSA) and a cathode, both parallel to each other.
With such type of anode within a 3 EA configuration, jmax‘s calculation is expected to be straightforward. Nonetheless, certain issues prevail. Occasionally, jmax is wrongly overestimated neglecting the surface of the anode that does not directly face the cathode.
Here, grown biofilms of the novel electroactive bacterium Geoalkalibacter subterraneus showed that the actual area of anode that contributes to jmax is the total PSA (or apparent geometric area) immersed in the electrolyte available to form a biofilm regardless the side of the anode that faced or opposed the cathode even in a medium with low conductivity such as urban wastewater, a niche of application for METs.
For the sake of normalization, researchers (and especially a “freshman” microbial electrochemist) are encouraged to: A) use the total PSA (or apparent geometric area) immersed in the electrolyte to calculate jmax or B) to cover edges and faces hidden of the anode with an electrical insulator to allow the flow of current on the side of the anode that directly faces the cathode prior calculation of jmax. This normalization can be conducted when the main goal is to quantify (and thus properly report) jmax produced when using (e.g.): a novel i) electroactive bacterium, ii) electrode material or iii) reactor design
Enzyme activity indicates soil functionality affectation with low levels of trace elements
No full textThe use of the soil can alter its functionality and influence the (bio)availability of any contaminants present. Our study considers two types of agricultural soils, rainfed and olive soils, managed according to conventional practices that apply contaminants directly to the soil (fertilizers, pesticides, fungicides, etc.) and receive contaminants from the atmosphere (traffic, industry, etc.); and a forest soil that is not subject to these agricultural practices. In this scenario, we consider a mixture of 16 trace elements (As, Ba, Be, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Se, Sb, Sn, V and Zn), since their interactions with the soil can produce synergistic and/or antagonistic effects that are not considered in most studies. We studied whether the content and (bio)availability of low concentrations of a mixture of trace elements affect the soil functionality in terms of the activity of some key enzymes We analysed the total, potentially and immediately available fractions, the soil parameters and soil enzyme activity. The results show that the functionality of the soils studied was affected despite the low concentrations of trace elements. The highest concentrations of total trace elements and available fractions were found in forest soils compared to the other two uses. Soil enzyme activity is best explained by the potentially available fraction of a mixture of trace elements and physico-chemical soil variables. In our study, pH, total nitrogen, organic carbon and fine mineral particles (silt and clay) had an influence on soil enzyme activity and the (bio)available fractions of trace elements