Implementation of the EU ecological flow policy in Italy with a focus on Sardinia

River ecosystems are characterised by a naturally high level of hydrodynamic perturbations which create aquatic-terrestrial habitats indispensable for many species, as well as for the human beings’ welfare. Environmental degradation and habitat loss caused by increasing anthropogenic pressures and global change affect freshwater aquatic ecosystems worldwide and have caused changes in water flow regimes and channels morphologies. These, in turn, decreased the natural flow capacity and reduced habitat availability, thus causing severe degradation of rivers’ ecological integrity. The ecological flow (e-flow) is commonly intended as the quantity, timing, duration, frequency and quality of water flows required to sustain freshwater, estuarine and near shore ecosystems and the human livelihoods and well being. Maintaining the e-flow represents a potential tool for restoring and managing river ecosystems, to preserve the autochthonous living communities, along with environmental services and cultural/societal values. In the last decade, methods for the determination of the e-flow in European rivers moved from a simply hydrological approach towards establishing a linkage between the hydrological regime and the good ecological status (GES) of the water bodies, as identified by the European Water Framework Directive (WFD; 2000/60/EC). Each Member State is required to implement and integrate into the River Basin Management Plans (RBMP) a methodology for the determination of the e-flow, ensuring that rivers can achieve and maintain the GES. The competent river basin authorities have thus to ascertain whether national methodologies can be applied to different river typologies and basin environment characteristics. In this context, we narratively review the e-flow assessments in the heterogeneous Italian territory, in particular on a water scant region such as Sardinia, by analysing laws, guidelines and focusing on study cases conducted with micro and meso-scale hydraulic-habitat approaches. In the sight of a more ecological-based application of national e-flow policy, we suggest that meso-habitat methods provide a valuable tool to overcome several limitations of current e-flow implementation in the Italian territory. However, to face future challenges, such as climate change adaptation, we stress the need for further experimental studies to update water management plans with greater attention for nature conservation

Developmental, hormone- and stress-modulated expression profiles of four members of the Arabidopsis copper-amine oxidase gene family

Copper-containing amine oxidases (CuAOs) catalyze polyamines (PAs) terminal oxidation producing ammonium, an aminoaldehyde and hydrogen peroxide (H2O2). Plant CuAOs are induced by stress-related hormones, methyl-jasmonate (MeJA), abscisic acid (ABA) and salicylic acid (SA). In the Arabidopsis genome, eight genes encoding CuAOs have been identified. Here, a comprehensive investigation of the expression pattern of four genes encoding AtCuAOs from the α and γ phylogenetic subfamilies, the two peroxisomal AtCuAOα2 (At1g31690) and AtCuAOα3 (At1g31710) and the two apoplastic AtCuAOγ1 (At1g62810) and AtCuAOγ2 (At3g43670), has been carried out by RT-qPCR and promoter::green fluorescent protein-β-glucuronidase fusion (GFP-GUS). Expression in hydathodes of new emerging leaves (AtCuAOγ1 and AtCuAOγ2) and/or cotyledons (AtCuAOα2, AtCuAOγ1 and AtCuAOγ2) as well as in vascular tissues of new emerging leaves and in cortical root cells at the division/elongation transition zone (AtCuAOγ1), columella cells (AtCuAOγ2) or hypocotyl and root (AtCuAOα3) was identified. Quantitative and tissue-specific gene expression analysis performed by RT-qPCR and GUS-staining in 5- and 7-day-old seedlings under stress conditions or after treatments with hormones or PAs, revealed that all four AtCuAOs were induced during dehydration recovery, wounding, treatment with indoleacetic acid (IAA) and putrescine (Put). AtCuAOα2, AtCuAOα3, AtCuAOγ1 and AtCuAOγ2 expression in vascular tissues and hydathodes involved in water supply and/or loss, along with a dehydration-recovery dependent gene expression, would suggest a role in water balance homeostasis. Moreover, occurrence in zones where an auxin maximum has been observed along with an IAA-induced alteration of expression profiles, support a role in tissue maturation and xylem differentiation events

Use of native species and biodegradable chelating agents in the phytoremediation of abandoned mining areas

Abstract BACKGROUND: The application of phytostabilization and assisted phytoextraction to the remediation of abandoned mining areas can be a valuable method to reclaim these areas without modifying soil and landscape characteristics. An in situ application of a continuous phytoextraction technique was carried out in the area of Campo Pisano (Sardinia, Italy), followed by a laboratory assisted phytoextraction test using the biodegradable chelating agents methylglycine diacetic acid (MGDA) and iminodissuccinic acid (IDSA). The plants used were Scrophularia canina subsp. bicolor, Cistus salviifolius and Teucrium flavum subsp. glaucum

Effect of hydraulic retention time on the electro-bioremediation of nitrate in saline groundwater

Bioelectrochemical systems (BES) have proven their capability to treat nitrate-contaminated saline groundwater and simultaneously recover value-added chemicals (such as disinfection products) within a circular economy-based approach. In this study, the effect of the hydraulic retention time (HRT) on nitrate and salinity removal, as well as on free chlorine production, was investigated in a 3-compartment BES working in galvanostatic mode with the perspective of process intensification and future scale-up. Reducing the HRT from 30.1 +/- 2.3 to 2.4 +/- 0.2 h led to a corresponding increase in nitrate removal rates (from 17 +/- 1 up to 131 +/- 1 mgNO3--N L-1d-1), although a progressive decrease in desalination efficiency (from 77 +/- 13 to 12 +/- 2 %) was observed. Nitrate concentration and salinity close to threshold limits indicated by the World Health Organization for drinking water, as well as significant chlorine production were achieved with an HRT of 4.9 +/- 0.4 h. At such HRT, specific energy consumption was low (6.8 center dot 10-2 +/- 0.3 center dot 10-2 kWh g-1NO3--Nremoved), considering that the supplied energy supports three processes simultaneously. A logarithmic equation correlated well with nitrate removal rates at the applied HRTs and may be used to predict BES behaviour with different HRTs. The bacterial community of the bio-cathode under galvanostatic mode was dominated by a few populations, including the genera Rhizobium, Bosea, Fontibacter and Gordonia. The results provide useful information for the scale-up of BES treating multi-contaminated groundwater

Digested blackwater treatment in a partial nitritation-anammox reactor under repeated starvation and reactivation periods

Wastewater source-separation and on-site treatment systems face severe problems in wastewater availability. Therefore, the effect of repeated short-term starvation and reactivation periods on a partial nitritation-anammox (PN/AMX) based processes were assessed treating digested blackwater at room temperature. Two sequencing batch reactors (SBR) were operated, one of them during 24 h/day the whole week (SBR-C, which served as control) and the other with repeated starvation/reactivation periods during the nights and the weekends (SBR-D), using simulated blackwater (300 mg N/L and 200 mg COD/L) as substrate. Results showed no remarkable differences in overall processes performance between both reactors, achieving total nitrogen removal efficiencies (NRE) around 90%. Furthermore, no significant variations were measured in specific activities, except for the aerobic heterotrophic one that was lower in SBR-D, presumably due to the exposure to anoxic conditions. Then, the technical feasibility of applying the PN/AMX system to treat real blackwater produced in an office building during working hours was successfully proved in a third reactor (SBR-R), with the same starvation/reactivation periods tested in SBR-D. Despite the low temperature, ranging from 14 to 21 °C, total NRE up to 95% and total nitrogen concentration in the effluent lower than 10 mg N/L were achieved. Moreover, the PN/AMX process performance was immediately recovered after a long starvation period of 15 days (simulating holidays). Results proved for the first time the feasibility and long-term stability (100 days) of applying the PN/AMX processes for the treatment (and potential reuse) of blackwater in a decentralized system where wastewater is not always availableThis work was funded by the Pioneer_STP (PCIN-2015-22 MINECO (AEI)/ID 199 (EU)) project by the WaterWorks2014 Cofunded Call (Water JPI/Horizon 2020) and by MEDRAR (IN852A 2016) project by the Galician Government. The work of G. Tocco was financially supported by the University of Cagliari (Italy) and by European Union within the framework of the Erasmus+ Traineeship Programme (2017-1-IT02-KA103-035458). A. Val del Rio is a Xunta de Galicia fellow (ED418B 2017/075). Authors from the USC belong to CRETUS Strategic Partnership (ED431E 2018/01) and to the Galician Competitive Research Group (GRC-ED431C 2017/29). All these programs are co-funded by FEDER (EU) fundsS