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Iron sulphate (FeSO4) and colloidal nano zero-valent iron (nZVI) as reducing agents were compared, with the aim of assessing their effectiveness in hexavalent chromium [Cr(VI)] removal from a contaminated industrial soil. Experiments were performed on soil samples collected from an industrial site where a nickel contamination, caused by a long-term productive activity, was also verified. The influence of reducing agents amount with respect to chromium content and the effectiveness of deoxygenation of the slurry were discussed. The soil was fully characterized before and after each test, and sequential extractions were performed to assess chemico-physical modifications and evaluate metals mobility induced by washing. Results show that both the reducing agents successfully lowered the amount of Cr(VI) in the soil below the threshold allowed by Italian Environmental Regulation for industrial reuse. Cr(VI) reduction by colloidal nZVI proved to be faster and more effective: the civil reuse of soil [Cr(VI)<2mg/kg] was only achieved using colloidal nZVI within 60min adopting a nZVI/Cr(VI) molar ratio of 30. The reducing treatment resulted in an increase in the amount of chromium in the oxide-hydroxide fraction, thus confirming a mechanism of chromium-iron hydroxides precipitation. In addition, a decrease of nickel (Ni) and lead (Pb) content in soil was also observed when acidic conditions were established., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Background: Extreme stool forms (1 and 2, or 6 and 7 of the Bristol stool scale) are frequent in patients with irritable bowel syndrome and are associated with colonic transit, but it is not known whether these alterations influence rectal reservoir function., Aims: To investigate rectal reservoir function by assessing magnetic resonance imaging reconstructions of rectal volume in healthy subjects and patients with irritable bowel syndrome, and to establish whether it varies depending on the bowel habits of the patients., Methods: Twelve healthy subjects and 20 patients with irritable bowel syndrome (with constipation, diarrhoea, mixed or undefined bowel habit according to the Rome III criteria) underwent pelvic magnetic resonance imaging in the absence of rectal sensations. T2 sagittal images were used to calculate rectal volume by multiplying inter-slice thickness by rectal area, and summing the inter-slice volumes., Results: Stool form was significantly different in the irritable bowel syndrome patients with diarrhoea or constipation, and bowel movements were more frequent in the irritable bowel syndrome patients than in the healthy subjects. Rectal volume was significantly smaller in the irritable bowel syndrome patients (27 ± 13 mL vs. 44 ± 21 mL; P=0.04), with no significant differences between the bowel habit sub-types., Conclusion: The reduced rectal volume in irritable bowel syndrome patients suggests that rectal tone is increased and that, at least in the absence of rectal sensations, the rectum is not over-distended by stools., (Copyright © 2011 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.)

Experimental tests of copper leaching from a low permeability soil are presented and discussed. The objective of the experiments was to investigate the influence of indigenous and added iron in the soil towards copper mobilization. Metals' leaching was performed by flushing (column tests) or washing (batch tests) the soil with an aqueous solution of ethylenediaminetetraacetic acid, EDTA. An excess of EDTA was used in flushing tests (up to a EDTA:Cu molar ratio of about 26.2:1), while, in washing tests, the investigated EDTA vs. copper molar ratios were in the range between 1 (equimolar tests) and 8. Copper extraction yield in flushing tests (up to about 85%) was found to depend upon contact time between the soil and the leaching solution and the characteristics of the conditioning solution. The saturation of the soil with a NaNO(3) solution before the treatment, favoured the flushing process reducing the time of percolation, but resulted in a lower metal extraction during the following percolation of EDTA. The indigenous iron was competitive with copper to form EDTA complexes only when it was present in the organic and oxides-hydroxides fractions. Artificial iron addition to the soil resulted in an increase of both the exchangeable iron and the iron bonded to the organic fraction of the soil, thus increasing the overall amount of iron available to extraction. In both batch and continuous tests, the mechanism of copper extraction was found to involve the former dissolution of metal salts, that lead to an initial high concentration of both copper and selected competitive cations (essentially Ca(2+)), and the following EDTA exchange reaction between calcium and copper complexes. The initial metal salts dissolution was found to be pH-dependant.

In this paper experimental tests of heavy metals mobilization from sediments collected from an Italian harbour are presented and discussed. Batch tests of washing with an aqueous solution of chelating agent were performed at selected liquid/solid (L/S) ratios and chelant concentration (0.01, 0.05 and 0.1M). Two chelating agents were chosen: EDTA and citric acid. The objective of the tests was to investigate metal mobilization and soil mineral dissolution promoted by the washing treatment. The study was focused on the mobilization of Pb, Zn, and Cu: their concentrations in the contact solution, together with Fe and Ca concentration, were monitored along time for 144h. Results of experimental tests performed at different chelant concentration and L/S ratio show EDTA effectiveness in mobilizing metals bond to the sediment. The overall amount of the three selected metals (Cu, Pb and Zn) extracted in the tests with EDTA varied in a quite narrow range (from 2.262 to 2.724mmol), while the higher was the EDTA concentration in the washing solution, the higher the dissolution of other competitive cations, such as Ca and Fe. In addition, a general difficulty in copper extraction from the organic fraction of the sediment was observed, due to the high stability of copper humate. The mechanism of metals extraction was found to involve the initial metals salts dissolution, that was pH-dependant, followed by the development of exchange reactions between the metal-EDTA complexes previously formed. Depending upon the pH of the washing solution an initial high Ca dissolution was observed, followed by dramatic reduction in Ca(2+) content, mainly determined by calcium carbonate precipitation, as a result of the increase of pH during mixing. Metal mobilization was evaluated performing sequential extraction tests: the dissolution of Cu, Pb and Zn from the carbonate fraction of the sediment was almost total, as the mobilization of Pb and Zn from the Fe-Mn oxides and hydroxides fraction. On the contrary, as a consequence of the mobilization induced by washing treatment, about 17% of the remaining Cu and 10% of the remaining Zn resulted in the exchangeable fraction. At the investigated operating conditions, citric acid was unable to extract Pb and Cu from the sediment, while at the strong acidic conditions maintained during the extractions with citric acid, a Zn mobilization up to the 80% of the initial amount was observed, depending upon the operating conditions in the extractions. In addition, because of the great affinity between citric acid and Fe, and the strong acidic conditions maintained during extraction, a high Fe dissolution was observed (up to about the 39% of the total Fe content in the sediment).

In this paper, the results of an experimentation on the production of granules suitable to be used as aggregates in cementitious or asphalt mixes are presented and discussed. The granules were obtained by granulating the non-metallic fraction of automotive shredder residues. In a preliminary separation step the fluff fraction containing mainly inert and non-metallic materials was sieved and analyzed for the metal content. In the following granulation step, the sieved fraction was mixed with binding materials, fly ash and a densifier agent, to produce granules of 5-30 mm of diameter and up to 1400 kg/m3 of specific weight. The granulation was carried out at room temperature in a rotating tank. Concrete samples prepared using as aggregates the produced granules showed a specific weight up to 1800 kg/m3 and a compressive strength up to about 55% of reference samples prepared using a calcareous aggregate, depending on the fluff content of the mixes, and on the nature of the binder and of the other components used.

In this study, chemical oxidation tests using H2O2 were performed on a solution contaminated with 100 mg l(-1) of pentachlorophenol (PCP). The effectiveness of electric arc furnace dust and hematite as heterogeneous catalysts was evaluated. Reactions were conducted at pH 2 for 24 h. Either H2O2 stabilized with KH2PO4 or un-stabilized H2O2 was used. Total organic carbon (T.O.C.) removal and chloride release from PCP molecule were monitored. Results showed that the maximum removal yields for electric arc furnace (EAF) dust (49.2% T.O.C., 56.7% Cl) were achieved when H2O2:PCP ratio was 10:1 and Fe:H2O2 = 1:5 for unstabilized H2O2 and when H2O2:PCP = 10:1 and Fe:H2O2 = 1:1 for stabilized H2O2 (48% T.O.C., 60.6% Cl). The maximum yield using hematite (45.2% T.O.C., 55.2% Cl) was obtained when H2O2:PCP ratio was 10:1 and Fe:H2O2 was 1:2. When EAF dust was used and Fe:H2O2 > 1:5, Cl release was higher than the one expected from T.O.C. removal.

A series of 24h batch tests of copper extraction from a sandy soil were performed by washing the soil with aqueous solution of ethylenediaminetetraacetic acid, EDTA. EDTA versus copper molar ratio were in the range between 1 (equimolar tests) and 13.3. The tests were performed at three selected liquid/solid ratio, 5, 12.5 and 25. Results show that decreasing the pH of the washing solution an higher copper extraction yield was achieved: an almost complete copper extraction was achieved after 23 h of mixing at a L/S = 5, and after 5 h of mixing at an L/S = 12.5. The mechanism of copper extraction was found to involve two sequential processes: the former dissolution of metal salts, that lead to an initial high concentration of both copper and some competitive cations (essentially Ca(2+)), and the following EDTA exchange reaction between calcium and copper complexes, which corresponded an increase of pH in the washing solution. A negligible extraction of Fe(3+) was also observed at the investigated operative conditions.

This work studies the effectiveness of a process proposed for the recovery of ethylenediaminetetraacetic acid (EDTA) and metal precipitation from soil flushing solutions. Two series of experimental tests were carried out on two samples of a soil artificially contaminated with copper or lead. The metals were extracted from the soil by flushing with a 0.05 M aqueous solution of EDTA sodium salt (E-Na(2)). Cu or Pb extraction efficiencies of about 95 and 98% were observed, respectively. The two extracted solutions were then treated to obtain EDTA recovery and metal precipitation from the aqueous solution. EDTA recovery was achieved in two steps. An initial evaporation treatment lead to reduce the solution volume by about 75%. This was followed by the acidification of the residue solution, which precipitated more than 93% of the used EDTA. The precipitated EDTA was removed by filtration, and was suitable for reuse after adding an alkaline agent. Metal precipitation from the filtered solution was performed using two different methods: an almost total (99.5%) Pb precipitation in alkaline conditions was achieved after complex destabilization through the sequential addition of ferric ions and sodium phosphate, while 93.6% copper precipitation was achieved with ferrous sulfate as a destabilization agent.

This paper presents a feasibility study in the field of the remediation of soils contaminated with atrazine. Experimental tests were performed on an artificially contaminated synthetic soil. Atrazine was removed from the soil by flushing with an aqueous solution at 5 vol.% of ethanol. Experimental tests of evaporation and Fenton's oxidation on the extracted solution were then performed in order to transform atrazine into its oxidation products. Tests were performed in the presence of a peroxide excess the ratio between Fe(2+) and H(2)O(2) was 1:10. Peroxide was first added in order to reduce the consumption of hydroxyl radicals by their reaction with the excess of Fe(2+). The degradation mechanism of atrazine during oxidation with Fenton's reagent in the presence of ethanol was investigated. Results showed that due to the non selective nature of Fenton's reagent a high consumption of reagent was needed to achieve a significant atrazine oxidation from solutions at 4.5 vol.% of ethanol. While at a Fe(2+) concentration of 3mM atrazine practically disappeared from pure aqueous solutions within 2h, a degradation yield of only 28.1% was observed in the presence of ethanol even when Fe(2+) concentration was 15 mM.

We have investigated the circadian rhythm of plasma atrial natriuretic peptide in 13 stable output heart transplanted patients, all without evidence of histological rejection and cardiac impairment, following antirejection therapy with Cyclosporine, Azathioprine and Prednisone. The 24-h pattern of plasma renin activity, plasma aldosterone and plasma cortisol has been studied as well. All the investigated variables were assayed six times over the 24-h span. The circadian time-qualified data were analyzed by ANOVA and Cosinor method. The 24-h mean levels of atrial natriuretic peptide, plasma renin activity and plasma aldosterone are significantly increased, while the concentrations of plasma cortisol are reduced in the heart transplanted recipients. ANOVA detected a significant within-day variability of all these humoral variables only in healthy subjects. A statistically significant circadian rhythm was validated by Cosinor procedure for all the investigated molecules in healthy subjects but not in heart transplanted patients. In our opinion, the increase of atrial natriuretic peptide is a counterregulatory mechanism aimed to compensate the cyclosporine-mediated activation of the renin-angiotensin-aldosterone system. The disappearance of the plasma renin activity, aldosterone and atrial natriuretic peptide circadian rhythm can be ascribed to the constant activation of the renin-angiotensin-aldosterone system. The hypocortisolism is due, in our opinion, both to glucocorticoid therapy and increase of plasma ANP concentration.

The time course of blood pressure in clinically healthy (pregnant and nonpregnant) women was followed by automatic ambulatory monitoring. Chronobiologic methods revealed the time course of dynamic rhythm characteristics as a function of gestational age. Differences were found between nonpregnant and pregnant women with an overall lowering during pregnancy of the rhythm-adjusted midline estimating statistic of rhythm (mesor).