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Bertin L.,University of Bologna | Capodicasa S.,University of Bologna | Fedi S.,University of Bologna | Zannoni D.,University of Bologna | And 3 more authors.
Journal of Hazardous Materials | Year: 2011

The role of anaerobic digestion (AD) on the decontamination and biomethanization of a PCB-spiked sludge obtained from a Membrane Biological Reactor (MBR) pilot plant was investigated throughout a 10-month batch experiment. The study was carried out under mesophilic (35 °C) and thermophilic (55 °C) conditions and was monitored by means of an integrated chemical, microbiological and molecular biology strategy. Remarkable PCB depletions (higher than 50% of the overall spiked PCBs) and dechlorinations were achieved under methanogenic conditions. The process was not affected by yeast extract addition. Both acetoclastic and hydrogenotrophic methanogens, together with some fermentative eubacteria, were found to persist in all PCB biodegrading microcosms. This finding, together with those obtained from parallel microcosms where specific populations were selectively inhibited, suggested that native methanogens played a key role in the biodegradation and dechlorination of the spiked PCBs.Taken together, the results of this study indicate that AD is a feasible option for the decontamination and the efficient disposal (with the production of a CH 4-rich biogas) of contaminated MBR sludge, which can be then employed as a fertilizer for agricultural purposes. © 2011 Elsevier B.V. Source


Ferri F.,University of Bologna | Bertin L.,University of Bologna | Scoma A.,University of Bologna | Marchetti L.,University of Bologna | And 2 more authors.
Chemical Engineering Journal | Year: 2011

The recovery of polyphenols from olive mill wastewaters (OMWs) decreases the toxicity of the effluent and permits the obtainment of high-added value natural antioxidants. Solid phase extraction (SPE) represents a valuable approach to obtain polyphenols from OMWs, since it relies on simple, cheap and environmental friendly procedures and agents. In this work, five resins with different physical properties, namely Amberlite XAD4, XAD7, XAD16, IRA96 and Isolute ENV+, were tested in parallel for their adsorption and desorption features towards an aqueous solution of ten target phenolic compounds typically occurring in OMWs. Water, methanol and ethanol, also under basic and acidified conditions, were tested as possible desorbing agents. Adsorption isotherms related to the mixture of all phenols and to each single phenol were determined. Experimental data well fitted with Langmuir isotherm model. The highest phenol adsorption (76%) was achieved with IRA96 polar resin. Conversely, non-polar adsorbents allowed higher desorption ratios. Almost 60% of the overall phenols originally occurring in the applied mixture were recovered by employing ENV+ and ethanol as the desorbing phase. Lower performances were achieved with the other recovery and desorption agents. The compound polarity generally influenced the adsorption ratios (the sorption capacities of non-polar resins increased by decreasing the compound polarity, and vice versa), while the desorption ones were not always affected by such a compound feature. These findings are of special interest in the perspective of developing an effective SPE procedure for the recovery of natural phenols from real OMWs. © 2010 Elsevier B.V. Source


Bertin L.,University of Bologna | Ferri F.,University of Bologna | Scoma A.,University of Bologna | Marchetti L.,University of Bologna | And 2 more authors.
Chemical Engineering Journal | Year: 2011

The recovery of polyphenols from olive mill wastewaters (OMWs) provides the double opportunity to obtain high-added value biomolecules and to reduce the phytotoxicity of the effluent. In this work, a solid phase extraction procedure for the recovery of OMW phenolic compounds recently developed on water solutions was applied and assessed on two different actual site OMWs. To this aim, the four most promising resins employed in the previous work, namely Amberlite XAD7, XAD16, IRA96 and Isolute ENV+, were tested and compared for their adsorption and desorption features towards the natural phenols occurring in the two real OMWs. Water, methanol and ethanol, also acidified with HCl 0.5ml/100mL, were tested as possible desorbing agents. Adsorption isotherms related to total phenols and to hydroxytyrosol, i.e., the most abundant (about 0.6gL -1) and valuable phenolic compound detected in the employed OMWs, were determined. Generally, all experimental data were well fitted with Freundlich isotherm model. The highest total phenols adsorption was achieved with ENV+ resin, which adsorbed almost completely the OMW hydroxytyrosol. The highest desorption ratios were generally obtained with acidified ethanol, which mobilized almost all polyphenols adsorbed onto resins ENV+, XAD7 and XAD16. Considering the integrated adsorption-desorption processes, ENV+ allowed to achieve (a) the highest recovery of total phenols when elution was done with acidified ethanol and (b) the highest specific recovery of hydroxytyrosol when non-acidified ethanol was used as the desorbing phase. © 2011 Elsevier B.V. Source


Puoci F.,University of Calabria | Scoma A.,University of Bologna | Cirillo G.,University of Calabria | Bertin L.,University of Bologna | And 4 more authors.
Chemical Engineering Journal | Year: 2012

An innovative biocompatible approach for the selective recovery of gallic acid (GA) from actual site olive mill wastewaters (OMWs) by means of Molecularly Imprinted Polymers (MIPs) was developed. Bulky MIPs with a high selectivity for GA were synthesized by a non-covalent approach using methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the crosslinker. Imprinting efficiency was evaluated in different water/ethanol solutions by determining α and ε parameter, by using pyrogallic acid as the template analogue: the highest GA recognition, both in terms of percentage and of imprinting effect (α= 32.7; ε= 4.2), was observed in pure ethanol. The efficiency of the developed extraction protocol was evaluated with an actual site OMW: a selective extraction of 80% of pure GA was achieved with high accuracy and precision, as shown by RSD% (4.3%) and recovery values (between 85% and 97%). © 2012 Elsevier B.V. Source


Scoma A.,University of Bologna | Pintucci C.,National Research Council Italy | Bertin L.,University of Bologna | Bertin L.,Interuniversitary Consortium Chemistry for the Environment | And 3 more authors.
Chemical Engineering Journal | Year: 2012

The present investigation was focused on improving the feasibility of large scale applications of a solid phase extraction (SPE) procedure dedicated to the recovery of polyphenols from olive mill wastewaters (OMWs). To this aim, a previously developed SPE procedure was optimized in terms of contact time without negatively affecting the overall process productivity. The possibility of regenerating and recycling both the solid phase (Amberlite XAD16 non-polar resin) and the extraction solvent (acidified ethanol) was also demonstrated. In particular, the resin was successfully reused in 10 consecutive SPE cycles (including washing and reactivation steps), allowing almost constant polyphenols adsorption and desorption ratios (81.44 ± 0.91% and 52.69 ± 5.57%, respectively). Up to 695. mL of ethanol per liter of exhausted extraction solvent were recovered by means of a rotary evaporator. Furthermore, the solvent conventionally used for resin activation (i.e., methanol) was successfully substituted by a more biocompatible solvent (i.e., ethanol). An ORAC value corresponding to 6979 μM of Trolox equivalents was observed for the concentrated polyphenolic solution, obtained as a result of rotary evaporator operations. Importantly, no substantial loss of radical scavenging and antioxidant activities occurred by means of the aforementioned operations dedicated to the recovery of ethanol from the obtained polyphenolic solution. © 2012 Elsevier B.V. Source

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