Passatore L.,CNR Institute of Agro-environmental and Forest Biology |
Passatore L.,University of Tuscia |
Rossetti S.,CNR Water Research Institute |
Juwarkar A.A.,Indian National Environmental Engineering Research Institute |
Massacci A.,CNR Institute of Agro-environmental and Forest Biology
Journal of Hazardous Materials | Year: 2014
This review summarizes the bioremediation and phytoremediation technologies proposed so far to detoxify PCB-contaminated sites. A critical analysis about the potential and limits of the PCB pollution treatment strategies by means of plants, fungi and bacteria are elucidated, including the new insights emerged from recent studies on the rhizosphere potential and on the implementation of simultaneous aerobic and anaerobic biodegradation processes.The review describes the biodegradation and phytoremediation processes and elaborates on the environmental variables affecting contaminant degradation rates, summarizing the amendments recommended to enhance PCB degradation. Additionally, issues connected with PCB toxicology, actual field remediation strategies and economical evaluation are discussed. © 2014 Elsevier B.V.
Romano E.,CNR Water Research Institute |
Preziosi E.,CNR Water Research Institute
International Journal of Climatology | Year: 2013
This study analyses the precipitation pattern in the Tiber River basin (central Italy) to determine trends, possible change points, periodicity and relationships with global climate indices, such as the North Atlantic Oscillation (NAO) index. The dataset is composed of daily rainfall time series, recorded at 21 to 102 different sampling stations, from 1952 to 2007. The following quantities were analysed at both an annual and seasonal scale: cumulative precipitation, number of rainy days, mean intensity, maximum daily precipitation and number of days needed to reach a given percentage of the cumulative precipitation. To compare the time series collected from different stations along with the different quantities, a standardization procedure based on the normal inverse function computed on the best-fit cumulative probability distribution was applied. The standardized time series from each station was regionalized by kriging. Trends were analysed using the Mann-Kendall test, and possible change points were determined using an algorithm based on the singular spectrum analysis. The periodicity of the signals was evaluated by cross-wavelet analysis. The results show a decreasing trend in annual precipitation (-8%) mainly because of decreasing winter precipitation (-16%). This trend appears to be related to a decrease in the number of rainy days. A significant change point in precipitation trends was identified in the mid-1980s. Conversely, those indices related to the intensity of precipitation (mean intensity, maximum daily precipitation) do not show significant trends. The cross-wavelet analysis performed on the annual/winter precipitation and NAO time series indicates the existence of four coherent periodic signals with periods of approximately 3, 4, 8 and 15 years. © 2012 Royal Meteorological Society.
Villano M.,University of Rome La Sapienza |
Scardala S.,University of Rome La Sapienza |
Aulenta F.,CNR Water Research Institute |
Majone M.,University of Rome La Sapienza
Bioresource Technology | Year: 2013
The anode of a two-chamber methane-producing microbial electrolysis cell (MEC) was poised at +0.200V vs. the standard hydrogen electrode (SHE) and continuously fed (1.08gCOD/Ld) with acetate in anaerobic mineral medium. A gas mixture (carbon dioxide 30vol.% in N2) was continuously added to the cathode for both pH control and carbonate supply. At the anode, 94% of the influent acetate was removed, mostly through anaerobic oxidation (91% coulombic efficiency); the resulting electric current was mainly recovered as methane (79% cathode capture efficiency). Low biomass growth was observed at the anode and ammonium was transferred through the cationic membrane and concentrated at the cathode. These findings suggest that the MEC can be used for the treatment of low-strength wastewater, with good energy efficiency and low sludge production. © 2012 Elsevier Ltd.
Masciopinto C.,CNR Water Research Institute |
Palmiotta D.,CNR Water Research Institute
Water Resources Research | Year: 2013
We examine the use of numeric flow solutions of the Navier-Stokes (N-S) equations to improve flow modeling in fractured karst aquifers. The N-S equations were discretized with both the meshed finite difference method (FDM) and the meshless smoothed particle hydrodynamics method. The results using the FDM model were successfully compared with those taken from the literature. The N-S equations were solved numerically for two practical problems in karst aquifers: (a) the horizontal displacement of the saltwater/freshwater sharp interface in fissures due to groundwater overexploitation and (b) the pressure and velocity profiles in fissures in the vicinity of an injection well. In the first problem, the numeric N-S solution suggests an exponential time advancement of the freshwater/saltwater interface in fissures. In the second problem, the unsteady water velocity and pressure profiles were determined in fissures having variable apertures in the vicinity of an injection well. The N-S simulation results agreed well with the data collected during the test, thereby removing any uncertainty in the estimation of the aquifer transmissivity. © 2013. American Geophysical Union. All Rights Reserved.
Masciopinto C.,CNR Water Research Institute
Journal of Environmental Management | Year: 2013
This study investigates the feasibility of management of aquifer recharge (MAR) in Lebanon by designing well barriers to remove seawater intrusion from the fractured carbonate aquifers. Groundwater flow and saltwater/freshwater 50% sharp interface have been modeled along the coastal area using the Ghyben-Herzberg theory. The groundwater flow simulations have been supported by field transmissivity estimations and depth measurements carried out on 44 wells during 2003. Results have shown the seawater intrusion in coastal aquifers at Jieh and Damour regions. Three well-injection barriers have been proposed. The water volumes for recharge and the barrier positions have been defined by means of groundwater flow simulations. MAR can provide a valuable contribution to colloid (even pathogen) removal from injectant water, although during water infiltration in subsoil the reduction of aquifer permeability causes clogging. A simple new model for estimating the soil-rock permeability reduction due to the well clogging has been presented. The MAR, including the soil aquifer treatment at Damour and Jieh regions, has been studied by considering aquifer transmissivity (and soil porosity) reduction caused by clogging. Furthermore, the appropriate mixing of the injectant water by using reclaimed water, groundwater and surface water can be simulated using the proposed models. The time required to achieve 5% of rock permeability reduction at the proposed well barriers ranged from 71 to 935d, by changing water quality and flow rate for recharge. This study can assist regional governments with water management in areas affected by scarcity of freshwater by implementing appropriate well-barrier projects. © 2013 Elsevier Ltd.
Queiros D.,University of Aveiro |
Rossetti S.,CNR Water Research Institute |
Serafim L.S.,University of Aveiro
Bioresource Technology | Year: 2014
In this work, hardwood spent sulfite liquor (HSSL), a complex feedstock originating from the pulp industry, was tested for the first time as a substrate for polyhydroxyalkanoate (PHA) production by a mixed microbial culture (MMC) under aerobic dynamic feeding (ADF) conditions. A sequencing batch reactor (SBR) fed with HSSL was operated for 67. days and the selected MMC reached a maximum PHA content of 67.6%. The MMC demonstrated a differential utilization of the carbon sources present in HSSL. Acetic acid was fully consumed, while xylose and lignosulphonates were partially consumed (30% and 14%, respectively). The selected culture was characterized by Fluorescence in Situ Hybridization (FISH). Bacteria belonging to the three main classes were identified: Alpha- (72.7. ±. 4.0%), Beta- (11.1. ±. 0.37%) and Gammaproteobacteria (10.3. ±. 0.3%). Within Alphaproteobacteria, a small amount of Paracoccus (4.2. ±. 0.51%) and Defluvicoccus related to Tetrad Forming Organisms (9.0. ±. 0.28%) were detected. © 2014 Elsevier Ltd.
Romano E.,CNR Water Research Institute |
Preziosi E.,CNR Water Research Institute
Ground Water | Year: 2010
The term sustainable pumping rate (SPR) is defined as the maximum pumping rate that can be maintained indefinitely without mining an aquifer, and is different from the concept of safe yield (SY), which takes into account also aspects related to the much wider concept of sustainability. The assessment of the SPR for the case study of Petrignano d'Assisi, an alluvial aquifer located in Central Italy, shows the need for a reliable estimate of the global water budget of the aquifer, particularly of the recharge under undisturbed conditions; however, the latter is not sufficient, because the SPR is affected also by the geometry of the aquifer, the hydraulic conductivity pattern, the variation of recharge/discharge ratio induced by the abstractions, and so on. All these aspects are analyzed by means of a numerical flow model calibrated both under undisturbed conditions (1974) and under exploitation conditions (1998 to 2004). The steady-state modeling results show that the relation between recharge and abstractions both at local and global scale is a key point in order to estimate a long-term SPR. Moreover, as it could be necessary to overexploit the aquifer for short periods, e.g., during drought episodes, the estimate of SPR must be performed also in transient conditions, in order to take into account the characteristic time of depletion and the successive recovery. Copyright © 2009 The Author(s). Journal compilation © 2009 National Ground Water Association.
Mascolo G.,CNR Water Research Institute |
Locaputo V.,CNR Water Research Institute |
Mininni G.,CNR Water Research Institute
Journal of Chromatography A | Year: 2010
Analysis of 11 polybrominated diphenyl ethers (PBDEs), tetrabromobisphenol A bis 2,3-dibromopropylether (TBBPA-bis), tetrachlorobisphenol A (TCBPA), tetrabromobisphenol A (TBBPA) and hexabromocyclododecanes (HBCDs) was optimized by ultrahigh pressure liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) operating in negative ion (NI) mode. Electrospray ionization (ESI), atmospheric pressure photoionization (APPI) and atmospheric pressure chemical ionization (APCI) sources were tested and for PBDEs APCI gave higher sensitivity than APPI while for TBBPA-bis APCI and APPI showed similar performance. ESI was the best option for TCBPA, TBBPA and HBCDs. Detection limits were between 20 and 59. fg for the compounds analyzed by ESI, 0.10 and 0.72. pg for PBDEs and 6. pg for TBBPA-bis. The matrix effect of sewage sludge extract was also tested showing negligible ion suppression for APCI and an increase of the background level of all investigated pollutants leading to a worsening of the limits of quantification by a factor between 1.2 and 3.3. The UPLC-APCI/MS/MS method for PBDEs, after pressurized liquid extraction (PLE), was validated by comparison with the concentration values from the NIST 1944 standard reference material. The advantages of the methods include low detection limits, PBDE congeners specificity using selected multiple reaction monitoring (MRM) transitions, and the absence of thermal degradation of higher PBDE congeners, especially BDE-209. The methods were applied for the determination of the above reported flame retardants in sewage sludge in order to get more information about the degradation on PBDEs (in particular BDE-209) during municipal wastewater treatments. © 2010 Elsevier B.V.
Casentini B.,CNR Water Research Institute |
Pettine M.,CNR Water Research Institute
Applied Geochemistry | Year: 2010
Microorganisms play an important role in As mobilization into groundwater by directly influencing As speciation or indirectly inducing solubilisation from As-bearing phases, such as Fe, Mn and Al oxides. Iron oxide dissolution could also be induced by siderophores, small-molecule compounds produced by microorganisms to favour Fe uptake. Well waters exceeding the potable water limit of 10μg As L-1 (0.133μM) have been widely reported in geothermal areas. Mechanisms responsible for these high As concentrations have not yet been thoroughly elucidated and the complexity of As mobilization in volcanic aquifers is still open to multiple interpretations. The present study was based on batch release experiments aimed at verifying and quantifying the effect of siderophores on As mobilization from volcanic rocks (lava, tuff, peperino and fallout deposit) at different pH and ligand concentration. In the experiments the siderophore trihydroxamate desferroxamine B (Dfob) was used and its effect on As release from volcanic rocks was manifest after the first days. The most favourable pH for As release was pH 6 while concentrations above 250μM Dfob considerably enhanced As and Fe concentrations in solution. The As release from rocks was between 2.0-10% at pH 6 and 2.4-8.8% at pH 8. The As/Fe ratio in solution changed with time suggesting different release mechanisms and higher mobility of As compared to Fe during the first phase of the experiment. The presence of siderophore increased Fe dissolution rates up to 10 orders of magnitude. The As release correlated with Al, Mn, Fe, Si, V, Ga and Sb and the release of all these elements increased with increasing Dfob concentration. In alkaline environments also Cu, Zn and Pb were mobilized. The presence of siderophores represents a possible trigger for As mobilization from iron binding minerals to the water phase, with interesting implications for groundwater quality, plant uptake and bacterial communities. © 2010 Elsevier Ltd.
Matturro B.,CNR Water Research Institute |
Rossetti S.,CNR Water Research Institute
Journal of Microbiological Methods | Year: 2015
Due to the direct involvement in the biodegradation of chlorinated solvents, reductive dehalogenase genes (RDase) are considered biomarkers of the metabolic potential of different strains of Dehalococcoides mccartyi (. Dhc). This is known to be the only microbe able to completely reduce toxic chlorinated solvents to harmless ethene. In the last years, several Molecular Biological Tools (MBTs) have been developed to optimize the detectability of Dhc cells and/or the RDase genes, with particular attention to the most important indicators of ethene formation, namely tceA and vcrA genes. Despite qPCR has been indicated as the MBT of choice, the use of CARD-FISH recently demonstrated to provide a more accurate quantification of Dhc cells in a wide concentration range, overcoming the drawbacks of loosing nucleic acids during the preparation of the sample associated with qPCR. CARD-FISH assays usually target 16S rRNA and up to date no protocol able to discriminate different Dhc strains by detecting RDase genes has been developed. This study reports the first evidence of in situ detection of tceA and vcrA genes into Dhc cells by applying a new procedure named geneCARD-FISH. Dhc strains carrying tceA and vcrA genes were identified and quantified in a PCE-to-ethene dechlorinating microbial enrichment and overall they represented 58.63%. ±. 2.45% and 40.46%. ±. 1.86% of the total Dhc cells, respectively. These values were markedly higher than those obtained by qPCR, which strongly underestimated the actual concentration of vcrA gene (0.08%. ±. 0.01% of Dhc 16S rRNA gene copies). The assay was successfully applied also for the analysis of environmental samples and remarkably strengthens the biomonitoring activities at field scale by providing the specific in situ discrimination of Dhc cells carrying the key-RDase genes. © 2015 Elsevier B.V.