Metal Tolerance Capability of Helichrysum microphyllum Cambess. subsp. tyrrhenicum Bacch., Brullo & Giusso: A Candidate for Phytostabilization in Abandoned Mine Sites.

Sardinia was known as an important mine pole in Europe during his history. Still after decades from mine closure, 75.000.000 m3 of mine waste, rich in heavy metals, were left abandoned causing a huge environmental legacy on the mine district area. Consequently, cost effective remediation is required. In this frame, phytoremediation is considered a feasible candidate. This research was focused on Helichrysum microphyllum subsp. tyrrhenicum, which is pioneer in xeric soils with low-functions, like mine tailings. The aim of this study was to evaluate its ability to extract heavy metals from mine soils and accumulate them in plant tissues and its suitability for phytostabilization. Sundry samples of soil, roots and epigean organ were collected through field sampling and analysed in order to obtain metals concentration and mineralogical characteristics. Our results indicate that this species tolerates high concentration of zinc, lead and cadmium, behaving as a species suitable for phytostabilization.

Bioaugmentation-Assisted Phytostabilisation of Abandoned Mine Sites in South West Sardinia.

Bioaugmentation-assisted phytoremediation implies the administration of selected plant growth promoting bacteria, which significantly improve plant growth and sequestration of heavy metals. In this work, 184 bacterial strains associated with roots of Pistacia lentiscus were isolated from plants spontaneously growing in the abandoned Sardinian mining areas (SW Sardinia, Italy) and phylogenetically characterised. Twenty-one bacterial isolates were assayed for properties relevant for plant growth promotion and metal tolerance. Five different strains, belonging to the genera Novosphingobium, Variovorax, Streptomyces, Amycolatopsis, Pseudomonas, were selected based on their properties for the greenhouse phytoremediation tests. Among the tested inocula, the strain Variovorax sp. RA128A, able to produce ACC deaminase and siderophore, was able to significantly enhance germination and increase length and weight of shoots and roots. Irrespective of the applied treatment, mastic shrub was able to accumulate Cd, Pb and Zn especially in roots.

Use of native plants for the remediation of abandoned mine sites in Mediterranean semiarid environments.

Abandoned tailing dumps from mining industry represent important sources of metal contamination in the surrounding environments. This study evaluates the potential of two Mediterranean native plants, Pistacia lentiscus and Phragmites australis, for phytoremediation of two Sardinian contaminated mine sites. A 6 months study has been conducted at greenhouse-controlled conditions with the aim of investigating the plant capability to tolerate high metal concentrations and to extract or immobilize them within the roots. The possibility to mitigate stress on the plants and improve treatment efficiency by adding compost as amendment was also evaluated. Both species were able to restrict accumulation of Cd, Pb and Zn to the root tissues exhibiting a metal concentration ratio of plant roots to soil bioavailable fraction higher than two (four in the case of Zn). However, the two species showed different adaptation responses, being the survival of P. australis after 6 months in contaminated soil lower (25 %-58 %) than that observed for P. lentiscus (77 %-100 %). Compost addition resulted in a lower metal uptake in tissues of both plants and a higher survival of P. australis, whilst almost no effect was observed as regard the growth of both species. The two tested species appear to be promising candidates for phytostabilization, P. lentiscus exhibiting a greater adaptability to heavy metal contaminated matrices than P. australis.

An experimental study on fermentative H2 production from food waste as affected by pH.

Batch dark fermentation experiments were performed on food waste and mixtures of food waste and wastewater activated sludge to evaluate the influence of pH on biological H2 production and compare the process performance with and without inoculum addition. The effect of a preliminary thermal shock treatment of the inoculum was also investigated as a means to harvest the hydrogenogenic biomass. The best performance in terms of both H2 generation potential and process kinetics was observed at pH=6.5 under all experimental conditions (no inoculum, and untreated or thermally treated inoculum added). H2 production from food waste was found to be feasible even without inoculum addition, although thermal pre-treatment of the inoculum notably increased the maximum production and reduced the lag phase duration. The analysis of the fermentation products indicated that the biological hydrogen production could be mainly ascribed to a mixed acetate/butyrate-type fermentation. However, the presence of additional metabolites in the digestate, including propionate and ethanol, also indicated that other metabolic pathways were active during the process, reducing substrate conversion into hydrogen. The plateau in H2 generation was found to mirror the condition at which soluble carbohydrates were depleted. Beyond this condition, homoacetogenesis probably started to play a role in the degradation process.

Biological treatment of nitrogen-rich refinery wastewater by partial nitritation (SHARON) process.

Wastewater discharges containing high nitrogen levels can be toxic to aquatic life and cause eutrophication. In this study, the application of the SHARON (Single reactor for High activity Ammonium Removal Over Nitrite) process for the treatment of refinery wastewater (sour water) was evaluated, in view of its coupling with the ANAMMOX (ANaerobic AMMonium OXidation) process. A Continuous Flow Stirred Tank Reactor was initially fed with a synthetic medium, and the applied NH4-N concentration and wastewater/synthetic medium ratio were progressively increased up to 2000 mgN/L and 100%, respectively. Despite the high potential toxic effect of the real wastewater, overall SHARON performance did not decrease with the increasing real wastewater/synthetic medium ratio, and biomass showed progressive acclimation to the toxic compounds in the real wastewater, as demonstrated by toxicity assessments. NH4-N and dissolved organic carbon removal efficiency were around 50% and 65%, respectively. Moreover, the effluent was characterized by a NO2-N/NH4-N ratio of 0.9 +/- 0.01 and low nitrate concentration (<30 mgN/L), in line with the requirements for the subsequent treatment by the ANAMMOX process.

Application of accelerated carbonation on MSW combustion APC residues for metal immobilization and CO2 sequestration.

The present study focuses on the application of an aqueous phase accelerated carbonation treatment on air pollution control (APC) residues from municipal solid waste combustion, aimed at assessing its influence on the environmental behaviour of the residue under concern, as well as the potential of the process in terms of sequestration of the CO2. APC residues are considered hazardous waste and must be treated before final disposal in order to achieve the immobilization/mobilization of critical contaminants such as heavy metals as well as mobilization of soluble salts. The treatment applied proved to be effective in reducing the mobility of Pb, Zn, Cr, Cu and Mo, the optimum final pH for the carbonated APC residues being in a range of 10-10.5, whilst a mobilization effect was noticed for Sb and no effect was assessed for chlorides. The effect of carbonation treatment on the contaminant release was further evaluated by means of a sequential extraction procedure, indicating that the distribution of contaminants on water soluble, exchangeable and carbonate fraction was modified after treatment. The CO2 sequestration potential assessed for the APC residues showed that the carbonation technology could be a technically viable option in order to reduce emissions from WtE plants.

Combined use of a transformed red mud reactive barrier and electrokinetics for remediation of Cr/As contaminated soil.

A reactive barrier (RB) of transformed red mud (TRM), a by-product of the refinement of bauxite in alumina production, was placed adjacent to the anode of an electrokinetic (EK) system with the aim of enhancing removal of chromium or arsenic, added singly to a low permeability clayey soil, and favouring entrapment. The innovative study focused on evaluation of the synergic interaction between the EK system and the RB, and of the efficiency when compared to traditional EK remediation (control tests). The results obtained underlined the successful outcome of treatment of the Cr(VI)-contaminated soil. In presence of the TRM RB, 19.4% wt. of total Cr content was detected in the anolyte and 20.6% wt. trapped in the anodic RB after 6d, versus 6.6% wt. in the anolyte and 8.8% wt. in the soil adjacent to the anode following the control run without RB. On increasing duration of treatment up to 12d, 60.8% wt. of total initial Cr was found in the anolyte and 25.5% wt. trapped in the RB, versus 9.1% wt. and 5.3% wt., respectively, after a control run of the same duration. Finally, on increasing the mass of TRM in the RB, 60.6% wt. of initial Cr content was found to have accumulated in the RB, with Cr being completely absent from the anodic chamber. Conversely, combined treatment was much less effective on As contaminated soil, at least under the operative conditions applied. Low initial As concentration and interference with iron oxides in the soil were likely the reasons underlying low efficiency while attempting As decontamination.

Increased prevalence of proliferative retinopathy in patients with type 1 diabetes who are deficient in glucose-6-phosphate dehydrogenase.

AIMS/HYPOTHESIS: Impaired activity of the pentose phosphate pathway of glucose metabolism caused by hereditary deficiency of its key regulatory enzyme glucose-6-phosphate dehydrogenase (G6PD) has consequences that may worsen or attenuate the course of diabetic complications. Decreased availability of NADPH can predispose to oxidative stress and endothelial dysfunction, but can also limit the activity of the polyol pathway and cholesterol synthesis. Reduced availability of pentose phosphates for nucleic acid synthesis could impair cell proliferation. We sought to learn in which direction G6PD deficiency affects diabetic retinopathy. METHODS: We enrolled patients who were G6PD-deficient or -sufficient with type 1 diabetes of duration 15 years or longer for whom HbA(1c) records were available for at least the previous 3 years. Renal failure and smoking were exclusion criteria. For each participant seven standard field colour photographs were obtained of each eye, and retinopathy was graded in a masked fashion. RESULTS: The clinical characteristics of the 19 G6PD-deficient patients studied (age 42 ± 9 years, diabetes duration 24 ± 6 years, average HbA(1c) over 3 years 6.7 ± 0.8%) were similar to those of the 35 G6PD-sufficient patients. Almost 90% of patients in both groups had retinopathy; however, proliferative retinopathy was noted solely among G6PD-deficient patients (28%, p = 0.0036 vs G6PD-sufficient). The G6PD-deficient patients also showed a trend for increased frequency of microalbuminuria. CONCLUSIONS/INTERPRETATION: The data suggest that G6PD deficiency accelerates the microvascular complications of diabetes, and that among the consequences of G6PD deficiency those that can enhance the damage caused by diabetes outweigh those that could be protective.

Effects of the cometabolite/growth substrate ratio on the aerobic degradation of 4-monochlorophenol.

Chlorinated phenolic compounds like 4-monochlorophenol (4CP) are characterized by high toxicity even at relatively low concentrations and by strong persistency in both water and soils. Since cometabolism was proved to enhance 4CP biological removal, a conventional Sequencing Batch Reactor (SBR) was used in this study for the cometabolic aerobic degradation of 4CP at different influent concentrations and volumetric organic loading rates (40-50 mg/L and 0.129-0.323 kgCOD-4CP/m3·d, respectively), with sodium acetate (NaAc) as the growth substrate. The effects of different 4CP/NaAc ratios on SBR performances were evaluated in terms of 4CP removal efficiencies and maximum specific removal rates in order to maximize reactor performances: a decrease in NaAc dosage as external growth substrate would lead to definitely lower operating costs. A positive correlation was observed between 4CP maximum specific removal rates and the applied 4CP/NaAc ratios, thus making further reduction in NaAc dosage possible.

[Effect of misclassification of the place of residence on incidence estimates: the example of child cancer in a local health authority in Rome, Italy]. / Misclassificazione della residenza nelle schede di Dimissione Ospedaliera ed effetti sulle stime di incidenza: l'esempio dei tumori in età pediatrica nella ASL RMD.

A study on cancer of the lymphatic and hematopoietic tissue among residents aged 0-14 years was conducted by the Local Health Unit RMD (Rome, Italy; period 2003-09; codes of the International Classification of Diseases, Ninth Revision, Clinical Modification: 200-208). Age and gender Standardized Mortality and Hospitalization Ratios were computed in order to compare observed and expected cases, using municipal rates as reference. Place of residence at the time of admission, as recorded in the Hospital Registry, was compared with the information recorded in the Municipal Registers and the correlation between the two sources was calculated by Cohen's Kappa. No mortality nor morbidity excesses were observed in the study area. Although 14% of children were not confirmed as being resident at the time of admission, the Cohen's Kappa indicates a strong correlation between the Municipal Registry and the Hospital Registry (84%). The analyses restricted to children with ascertained residence did not yield different results. For those whose residence was not confirmed, the mismatch of information between the Municipality Registry and the Hospital Registry needs to be clarified.

Landfill gas generation after mechanical biological treatment of municipal solid waste. Estimation of gas generation rate constants.

Mechanical biological treatment (MBT) of residual municipal solid waste (RMSW) was investigated with respect to landfill gas generation. Mechanically treated RMSW was sampled at a full-scale plant and aerobically stabilized for 8 and 15 weeks. Anaerobic tests were performed on the aerobically treated waste (MBTW) in order to estimate the gas generation rate constants (k,y(-1)), the potential gas generation capacity (L(o), Nl/kg) and the amount of gasifiable organic carbon. Experimental results show how MBT allowed for a reduction of the non-methanogenic phase and of the landfill gas generation potential by, respectively, 67% and 83% (8 weeks treatment), 82% and 91% (15 weeks treatment), compared to the raw waste. The amount of gasified organic carbon after 8 weeks and 15 weeks of treatment was equal to 11.01+/-1.25kgC/t(MBTW) and 4.54+/-0.87kgC/t(MBTW), respectively, that is 81% and 93% less than the amount gasified from the raw waste. The values of gas generation rate constants obtained for MBTW anaerobic degradation (0.0347-0.0803y(-1)) resemble those usually reported for the slowly and moderately degradable fractions of raw MSW. Simulations performed using a prediction model support the hypothesis that due to the low production rate, gas production from MBTW landfills is well-suited to a passive management strategy.

Titration biosensors for the estimation of the biochemical nitrate demand of municipal and industrial wastes.

An anoxic titrimetric test was investigated for measuring denitrification potential of different wastewaters, both municipal and industrial, and to quantify the denitrifying activity in an activated sludge system. The method measures the amount of acid that is required to maintain the pH set-point value in a batch denitrification experiment, and it was performed using a DENICON (denitrification controller) biosensor. The amount of acid is proportional to the nitrate used to oxidise the biodegradable chemical oxygen demand present in the wastewater, while the acid consumption rate is used to derive the denitrifying activity. The wastewaters tested were a municipal wastewater (MW), an industrial-municipal wastewater (MIW; 70% and 30%, respectively), and four industrial wastewaters drawn from an ice-cream factory (IW1), a beet-sugar factory (IW2), a brewery (IW3), and a tuna cannery industry (IW4). Good correlation between titration data and analyses was found.

Use of industrial wastewaters for the optimization and control of nitrogen removal processes.

In this experimental study the characterization of 2 industrial wastewaters, coming from an ice cream production industry (IW1) and a beet-sugar factory (IW2), with respect to their readily biodegradable fraction and denitrification potential, has been performed. To this end physical-chemical and biological characterization methods, both anoxic and aerobic, were used. Moreover a pilot scale SBR fed with municipal wastewater was started to verify the effect of the gradual addition of the concentrated organic wastewaters during the anoxic phase. The SBR was initially fed only with a primary municipal wastewater, then the organic load was increased by adding to the feed, during the anoxic phase, a small amount of the IW1 (second period). Once the initial conditions were restored the load was again raised using the second industrial wastewater (IW2) (third period). With those additions the nitrogen removal efficiency increased from 26% to 50%, in the case of the IW1 and from 23% to 53% in the case of the wastewater IW2, without any negative effect on the global performance of the system. In addition, periodical kinetic studies of denitrification and nitrification in the SBR, were performed.

Management of municipal solid waste incineration residues.

The management of residues from thermal waste treatment is an integral part of waste management systems. The primary goal of managing incineration residues is to prevent any impact on our health or environment caused by unacceptable particulate, gaseous and/or solute emissions. This paper provides insight into the most important measures for putting this requirement into practice. It also offers an overview of the factors and processes affecting these mitigating measures as well as the short- and long-term behavior of residues from thermal waste treatment under different scenarios. General conditions affecting the emission rate of salts and metals are shown as well as factors relevant to mitigating measures or sources of gaseous emissions.

Iron concentration and distribution in the newborn liver.

Recent observations on a correlation between fetal serum ferritin and gestational age, consistent with an increase in fetal iron stores during pregnancy, led us to study liver iron content in 22 human stillborns, newborns and infants of different gestational and postnatal age. At autopsy, a longitudinal liver slice was subdivided into ten blocks. Each sample was analyzed for iron content by atomic absorption spectroscopy. The mean iron concentration in the studied livers was 21.6 microM/g dry tissue (d.t.). A striking interindividual variability in iron content was observed: the hepatic concentration of the metal ranged from 3.3 to 64.4 microM/g d.t. No correlation was found between the hepatic iron concentration and gestational age or other clinical parameters of the patients studied. Moreover, the total storage iron of the liver did not appear to be correlated with the gestational age. The analysis of iron concentration in ten blocks in each liver revealed an irregular distribution of the metal. Lobar differences were observed, with a tendency of the left lobe to accumulate more iron than the right one. Furthermore, striking differences in iron content were found between adjacent liver samples, ranging in one instance from 4.5 up to 109.0 microM/g of dry tissue. Perls' stain for iron was positive in 7 out of the 22 livers examined, showing an irregular acinar distribution, with preferential periportal localization. Our data show that the newborn liver can be considered an interesting model for the study of iron storage.(ABSTRACT TRUNCATED AT 250 WORDS)