Redox Dependent Arsenic Occurrence and Partitioning in an Industrial Coastal Aquifer: Evidence from High Spatial Resolution Characterization of Groundwater and Sediments

Superlative levels of arsenic (As) in groundwater and sediment often result from industrial pollution, as is the case for a coastal aquifer in Southern Italy, with a fertilizer plant atop. Understanding conditions under which As is mobilized from the sediments, the source of that As, is necessary for developing eective remediation plans. Here, we examine hydrogeological and geochemical factors that aect groundwater As concentrations in a contaminated coastal aquifer. Groundwater has been subject to pump-and-treat at a massive scale for more than 15 years and is still ongoing. Nevertheless, As concentrations (0.01 to 100 mg/L) that are four orders of magnitude more than Italian drinking water standard of 10 g/L are still present in groundwater collected from about 50 monitoring wells over three years (2011, 2016, and 2018). As was quantified in three dierent locations by sequential extractions of 29 sediment cores in 2018 (depth 2.5 m to 16.5 m b.g.l.), combined with groundwater As composition, the aqueous and solid partitioning of As were evaluated by partition coecient (Kd) in order to infer the evolution of the contaminant plumes. Most sediment As is found in easily extractable and/or adsorbed on amorphous iron oxides/hydroxides fractions based on sequential extractions. The study shows that As contamination persists, even after many years of active remediation due to the partitioning to sediment solids. This implies that the choice of remediation techniques requires an improved understanding of the biogeochemical As-cycling and high spatial resolution characterization of both aqueous and solid phases for sites of interes

Relationship between rainfall and water table in a coastal aquifer: the case study of Castelporziano presidential estate

This study is focused on the analysis of seasonal and annual variability in groundwater levels of the coastal aquifer of Castelporziano Presidential Estate, a protected area of 59 Km2 located in the periphery of Rome. A comparison with the local trends of rainfall at “Castello” gauging station at different time scales (monthly, seasonal and annual) has been carried out. The results highlight differences between the coastal area and eastern and northern sector of the Estate. Indeed, the seasonal effect due to local meteoric recharge is direct and regular during the year in the coastal area in respect to the eastern and northern sectors of the Estate. Moreover, annual steady regime and multi-year trend of groundwater levels suggest the contribution from the adjacent volcanic aquifer of Albani Hills. In the latter case, the regional circulation of groundwater is affected by the effects of intense withdrawals. The maintenance of the monitoring network will allow to define the flow paths of the groundwater that characterize the coastal aquifer of Castelporziano

A Technical Note on the Application of a Water Budget Model at Regional Scale: A Water Manager’s Approach towards a Sustainable Water Resources Management

Evaluating the quantitative status of groundwater has always represented an attractive method of modelling development for scientific research purposes and, at the same time, an essential planning tool for water managers. Today, in addition to the traditional modelling and management applications, the quantification of groundwater resources increasingly aims at evaluating effective water bodies’ health. In fact, the founding principles introduced by the most recent international directives in terms of water protection are specifically addressed to natural ecosystems’ protection complying with different socio-economic conditions. In this context, Acea Ato2, a water utility operating in central Italy, here proposes the implementation of an analytical water budget model for the assessment of the groundwater potential recharge status throughout its managed area

A Technical Note on the Application of a Water Budget Model at Regional Scale: A Water Manager’s Approach towards a Sustainable Water Resources Management

Evaluating the quantitative status of groundwater has always represented an attractive method of modelling development for scientific research purposes and, at the same time, an essential planning tool for water managers. Today, in addition to the traditional modelling and management applications, the quantification of groundwater resources increasingly aims at evaluating effective water bodies’ health. In fact, the founding principles introduced by the most recent international directives in terms of water protection are specifically addressed to natural ecosystems’ protection complying with different socio-economic conditions. In this context, Acea Ato2, a water utility operating in central Italy, here proposes the implementation of an analytical water budget model for the assessment of the groundwater potential recharge status throughout its managed area

Groundwater monitoring in regional discharge areas selected as “hydrosensitive” to seismic activity in Central Italy

The aim of this study was to identify potential patterns of hydrogeological and geochemical changes in response to seismic activity, including possible variations of ion concentrations, gas compositions, and isotopic ratios in groundwater. Different monitoring areas in Central Italy have been selected, located in regional discharge areas with abundant groundwater resources. They are located near active normal faults, along the southeast-ward prolongation of the faults that nucleated the L’Aquila 2009 Mw 6.3 event and more recently the seismic sequence of Amatrice–Norcia 2016–2017. The test-site selection has been based on both seismic and hydrogeological criteria. The areas are characterized by low strain rate, long frequencies of earthquake occurrence and high depth of the brittle-ductile transition, which are indicators of potential future earthquakes. In this framework, the hydrogeological setting is considered essential for obtaining reliable results applied to seismic purposes. Springs with long and deep flow paths in the regional aquifers are under monitoring. Indeed, the regional groundwater flows are also clearly influenced by deep fluids contribution. Consequently, the hydrogeological monitoring has been enhanced by continuous active radon and carbon dioxide probes, installed in some of the monitored springs. The results show significant inferences between hydrogeology and seismicity, having different characteristics in relationship with Amatrice–Norcia 2016–2017 seismic sequence and with global minor seismic activity. Based on these preliminary results, the second phase of this study is aimed to reinforce monitoring in selected springs and wells

Groundwater changes in the Nera river valley due to the August-October 2016 seismic sequence in central Italy

Hydrologic regime, earthquake, central Apennines, groundwater discharge

In situ arsenic immobilisation for coastal aquifers using stimulated iron cycling. Lab-based viability assessment

Arsenic (As) is one of the most harmful and widespread groundwater contaminants globally. Besides the occurrence of geogenic As pollution, there is also a large number of sites that have been polluted by anthropogenic activities, with many of those requiring active remediation to reduce their environmental impact. Cost-effective remedial strategies are however still sorely needed. At the laboratory-scale in situ formation of magnetite through the joint addition of nitrate and Fe(II) has shown to be a promising new technique. However, its applicability under a wider range of environmental conditions still needs to be assessed. Here we use sediment and groundwater from a severely polluted coastal aquifer and explore the efficiency of nitrate-Fe(II) treatments in mitigating dissolved As concentrations. In selected experiments >99% of dissolved As was removed, compared to unamended controls, and maintained upon addition of lactate, a labile organic carbon source. Pre- and post-experimental characterisation of iron (Fe) mineral phases suggested a >90% loss of amorphous Fe oxides in favour of increased crystalline, recalcitrant oxide and sulfide phases. Magnetite formation did not occur via the nitrate-dependent oxidation of the amended Fe(II) as originally expected. Instead, magnetite is thought to have formed by the Fe(II)-catalysed transformation of pre-existing amorphous and crystalline Fe oxides. The extent of amorphous and crystalline Fe oxide transformation was then limited by the exhaustion of dissolved Fe(II). Elevated phosphate concentrations lowered the treatment efficacy, indicating joint removal of phosphate is necessary for maximum impact. The remedial efficiency was not impacted by varying salinities, thus rendering the tested approach a viable remediation method for coastal aquifers

Confirmatory factor analysis of the Patient Assessment of Constipation-Symptoms (PAC-SYM) among patients with chronic constipation

Background and aim: PAC-SYM is widely adopted to asses constipation severity. However, it has been validated in a small sample, few items have been included based on expert opinion and not on empirical grounds, and its factor structure has never been replicated. We aimed at evaluating the psychometric properties of PAC-SYM in patients with chronic constipation. Methods: We enrolled 2,203 outpatients with chronic constipation in two waves. We used wave I sample to test the psychometric properties of the PAC-SYM and wave II sample to cross-validate its factor structure, to assess criterion validity, responsiveness to clinical change, and its minimal clinically important difference. Results: Only a minority of patients reported any rectal tearing (38 %). Deletion of such item leads to a 11-item version (M:PAC-SYM). The remaining items in the rectal domain were moderately correlated with the stool domain. Exploratory factor analysis and confirmatory factor analysis revealed a bifactor structure with two subscales (stool and abdominal symptoms) and a general severity factor. The M:PAC-SYM demonstrated excellent reliability, moderate correlation with SF-12 and treatment satisfaction (r = 0.28-0.45), discrimination across Rome III criteria for functional constipation and abdominal pain, and responsiveness to clinical change (β = -0.49; ω2 = 0.25). M:PAC-SYM minimal clinically important difference was 0.24. Conclusion: Our analysis shows that the rectal domain may not represent a relevant cluster of symptoms for patients with chronic constipation. We developed a modified version of the PAC-SYM which might better represent symptom severity of most patients seeking care in gastroenterology referral centers

Bloating is associated with worse quality of life, treatment satisfaction, and treatment responsiveness among patients with constipation-predominant irritable bowel syndrome and functional constipation

Background: The management of bloating is unclear and its relationship with patients' well-being and treatment satisfaction independent of other abdominal symptoms is uncharacterized. We evaluated the association of bloating with patient-reported outcomes. Methods: Thirty-nine centers for functional gastrointestinal disorders joined the laxative inadequate relief survey. We enrolled 2203 consecutive outpatients with functional constipation (FC) or constipation-predominant irritable bowel syndrome (IBS-C) in two cross-sectional waves. Both wave 1 and 2 included the SF-12, the patient assessment of constipation-symptoms (PAC-SYM), and the treatment satisfaction questionnaire for medication (TSQM-2). Wave 2 only included a global rating of change (GRC) scale to assess patients' assessment of efficacy concerning treatment switches occurred in the 3 months prior to the interview. Bloating in the abdomen was defined on the basis of PAC-SYM item 3. Key Results: The average age was 50.1 years (SD, 16.7) and 82.1% of patients were women. The prevalence of bloating was 91.6% (n = 1970). Bloating was associated with SF-12 Physical Composite Score (p < 0.01), SF-12 Mental Composite Score (p < 0.01), GRC (p < 0.01), Satisfaction with treatment effectiveness (p < 0.01), convenience of administration (p < 0.01), and side effects (p < 0.01) after adjustment for possible confounders. Conclusions & Inferences: Our data suggest that patients regard bloating as a key element in assessing clinical changes and treatments' efficacy as this symptom exerts a strong influence on patient-reported outcomes independent of possible confounders and other symptoms of constipation. Our data provide the rationale to investigate the efficacy and tolerability of new treatments specifically addressing this important, yet disregarded, patients' complain