Amorphous titanium hydroxide and boron-doped (B-doped) sodium titanates hydrates were synthetized and used as adsorbents for the removal of Pb(2+) from water. The use of sodium borohydride (NaBH4) and titanium(IV) isopropoxide (TTIP) as precursors permits a very easy synthesis of B-doped adsorbents at 298K. The new adsorbent materials were first chemically characterized (XRD, XPS, SEM, DRIFT and elemental analysis) and then tested in Pb(2+) adsorption batch experiments, in order to define kinetics and equilibrium studies. The nature of interaction between such sorbent materials and Pb(2+) was also well defined: besides a pure adsorption due to hydroxyl interaction functionalities, there is also an ionic exchange between Pb(2+) and sodium ions even working at pH 4.4. Langmuir model presented the best fitting with a maximum adsorption capacity up to 385mg/g. The effect of solution pH and common ions (i.e. Na(+), Ca(2+) and Mg(2+)) onto Pb(2+) sorption were also investigated. Finally, recovery was positively conducted using EDTA. Very efficient adsorption (>99.9%) was verified even using tap water spiked with traces of Pb(2+) (50ppb).

Alternative approaches for obtaining biodiesel from municipal sludge have been successfully investigated.In order to avoid the expensive conventional preliminary step of sludge drying, dewatered sludge(TSS: 15 wt%) was used as starting material. The best performance in terms of yield of fatty acid methylesters (18 wt%) with the lowest energy demand (17 MJ kg1FAME) was obtained by a new two-step approachbased on hexane extraction carried out directly on dewatered acidified (H2SO4) sludge followed by methanolysisof extracted lipids. It was found that sulphuric acid plays a key role in the whole process not onlyfor the transesterification of glycerides but also for the production of new free fatty acids from soaps andtheir esterification with methanol. In addition to biodiesel production, the investigated process allowsvalorization of primary sludge as it turns it into a valuable source of chemicals, namely sterols(2.5 wt%), aliphatic alcohols (0.8 wt%) and waxes (2.3 wt%).

The disposal of municipal sludge represents a relevant environmental problem in the field of wastewater treatment. As amatter of fact, 80 g of solids are produced per equivalent habitant per day. In detail, 60% comes from the primary treatmentand 40% from the secondary one. The sludge collected from these two different steps is made of two very different kind ofbiomasses: the primary sludge, is basically constituted by a large organic component (cellulose, lipids and proteins) and aminor inert one, while the secondary sludge is made of the biomass produced during the demolition of the soluble BOD.Such differences are going to open new distinguished uses for the two kinds of sludge [1]. Actually the production ofsecondary sludge can be drastically reduced by a new technology whose acronym is SBBGR[2] thus limiting the problem tothe disposal of primary sludge. In the last years, there have been some examples of sludge valorisation, in particular of itslipid fraction, to afford Fatty Acids Methyl Esters (FAMEs, namely biodiesel). The common approach used consists intoworking directly on a dry sludge with methanol and sulphuric acid as catalyst obtaining 11-14% of FAMEs from primarysludge and only 2% from secondary sludge [3]. Such an approach requires a high energy demand to obtain the dry sludge asstarting raw material for the alcoholysis process, from the dewatered sludge, the real product obtained from the sludgetreatment in a wastewater plant.In this work we present an inedited approach in which the starting raw material is the dewatered sludge (TSS = 20%)coming from the municipal wastewater treatment plant of Bari West (a Soutern Italy town). Two different methods havebeen used and compared: 1) the direct alcohlolysis of the dewatered sludge and 2) the preliminary extraction with hexanewith the subsequent alcoholysis of the oily residue. In both cases the energy demand per kilo of the final product result to belower than the energy required with the common approach.From a chemical point of view, a detailed analysis of the starting system has been carried out evidencing that together withthe glycerides, also free fatty acids (FFAs) and soaps are present in the sludge. For this reason, the trans-esterification ofglycerides is not the only reaction involved in the production of FAMEs, but direct esterification of FFAs and the splittingof soaps into the relevant FFAs are also involved in the whole process. Sulphuric acid plays a key role in the overall processas catalyst not only for the trans-esterification of glycerides (as already mentioned) [2] but even for the direct esterificationof FFAs in addition to work as strong acid for producing new FFAs from the soaps.The best results in term of yields of FAMEs (14% of the dry solids) have been obtained with the approach of hexaneextraction operated directly on the dewatered sludge, with a subsequent methanolysis catalysed by sulphuric acid at 5%w.Wi

A very detailed study was carried out on separation of lipids from wet sewage scum taken from several wastewater treatment plants (WWTPs). A solvent-less separation of lipids was optimized by simply heating sewage scum at 353 K and centrifuging the heated mass at 4000 rpm per 1 min [1]. Recoverability of 93-99% of total oils was determined. Extracted lipids have a very similar composition in terms of free fatty acids (FFAs), calcium soaps (32-40%wt) and glycerides (mono-, di- and tri-glycerides were practically absents), as well as fatty acid profiles in all of samples studied. Since mainly composed of FFAs, once separated, lipids were converted into biodiesel through a direct esterification process.Reaction conditions were optimised using the desirability function applied on the response surface methodology analysis of a Box-Behnken factorial design of experiments. By carrying out the reaction at 72°C for 120 min and using AlCl3·6H2O as a catalyst (1.5% mol of Al respect to fatty acids), almost 94% of the starting acids were converted into methyl esters [2]. At the end of the reaction, a biphasic system was obtained in which the upper methanolic phase, which contained most of the starting catalyst, was separated from the heaviest phase, mainly composed of fatty acid methyl esters. Such a distribution not only allowed the biodiesel to be easily separated, but also catalysts were efficiently recovered and reused for at least four times, determining a total TON greater than 200,without revealing any loss of its activity [3].This efficient separation between biofuel produced and unreacted methanol allow a three sequential batch reactors to be run, in which methanol and catalysts were charged in counter current respect to starting feedstock. In this way, the complete conversion (>99%) of starting FFAs into FAMEs was perfectly matched with using the minimum amount of reactants under very mild conditions (345 K, 2 h). The overall convenience of the process was completed by the anaerobic digestion of fibrous residues obtained from centrifugation of starting sewage scum: the final biogas resulted largely enough to sustain the overall heat of process [4].

Three different chemical oxidation processes were investigated in terms of their capability to degrade organic chemical components of real mature landfill-leachate in combination with biological treatment run in a Sequencing Batch Biofilter Granular Reactor (SBBGR). H2O2, H2O2 + UV and O3 were integrated with SBBGR and respective effluents were analyzed and compared with the effluent obtained from biological SBBGR treatment alone. In agreement with their respective oxidative power, conventional bulk parameters (residual COD, TOC, Ntot, TSS) determined from the resulting effluents evidenced the following efficacy ranking for degradation: SBBGR/O3 > SBBGR/UV + H2O2 > SBBGR/H2O2 > SBBGR. A more detailed characterization of the organic compounds was subsequently carried out for the four treated streams. For this, effluents were first subjected to a sample preparation step, allowing for a classification in terms of acidic, basic, strongly acidic and strongly basic compounds, and finally to analysis by liquid chromatography/high resolution mass spectrometry (LC/HR-MS). This classification, combined with further data post-processing (non-target screening, Venn Diagram, tri-dimensional plot and Principal Component Analysis), evidenced that the SBBGR/H2O2 process is comparable to the pure biological oxidation. In contrast, SBBGR/O3 and SBBGR/UV + H2O2 not only resulted in a very different residual composition as compared to SBBGR and SBBGR/H2O2, but also differ significantly from each other. In fact, and despite of the SBBGR/O3 being the most efficient process, this treatment remained chemically more similar to SBBGR/H2O2 than to SBBGR/UV + H2O2. This finding may be attributable to different mechanism of degradation involved with the use of UV radiation. Apart from these treatment differences, a series of recalcitrant compounds was determined in all of the four treatments and partly identified as hetero-poly-aromatic species (humic acids-like species). ? 2018 Elsevier B.V.

In this paper, we present the results of a study on 5-HMF production from fructose by means of heterogeneous catalysts in aqueous media. Mild conditions were used, setting the temperature between 393 K and 443 K. Cerium(IV) phosphates, different from other metal(IV)-phosphates, such as titanium and zirconium, have been characterized only recently. Ce-phosphates are quite complex structures as they show several arrangements. They undergo leaching of the phosphate group as phosphoric acid with consequent slow de-activation of the catalysts. The leaching rate depends on the nature and on the temperature of the calcination of the original phosphates. This opened the question whether the conversion was driven by the heterogeneous catalysts or by the soluble phosphoric acid. A specific test has demonstrated that the solid catalysts are responsible for the conversion of fructose into 5-HMF, more than the liquid phase. We have also demonstrated that the leached phosphate is substituted by fructose on the solid catalyst. A best yield of 52% with selectivity of 93% in batch and 24% in a flow reactor at 443 K (single pass) with a selectivity also > 95% were obtained.

Wastes produced by oil/water separation at the wastewater treatment plant of Bari West (Southern Italy) were taken, characterized and converted. About 12% of this material was composed of greases, mainly made of free fatty acids (50%) and soaps (34%), and was easily separable by the aqueous phase through a hot centrifugation. After chemical activation of this fatty fraction, a direct esterification was carried out under very mild conditions (320 K and atmospheric pressure), converting more than 90% of the original free fatty acids into the respective methyl esters in less than 4 h, by using AlCl3 center dot 6H(2)O. The activation energy correlated to the use of this catalyst was also calculated (Ea(est) = 43.9 kJ mol (1)). The very low cost of the biodiesel produced (0.45 (SIC) L (1)) and the associated relevant specific energy (5.02 MJ kg(FAMEs)(-1)) make such a process a really sustainable and effective example of valorization of a waste. (C) 2013 Elsevier Ltd. All rights reserved.

A very efficient separation of lipids from wet sewage scum was optimised and positively tested on samples taken from several wastewater treatment plants (WWTPs). By simply heating sewage scum at 353 K and centrifuging the heated mass at 4000 rpm per 1 min, a recoverability of 93-99% of total oils was always obtained. This procedure resulted to be effective on samples with very different starting water contents. In all cases, extracted lipids have a very similar composition in terms of free fatty acids (FFAs), calcium soaps (32-40%wt) and glycerides (mono-, di- and tri-glycerides were practically absents), as well as fatty acid profiles. Once separated, lipids were converted into biodiesel through a direct esterification process carried out by adopting three sequential batch reactors, in which methanol and catalysts were charged in counter current. In this way, the complete conversion (>99%) of starting FFAs into FAMEs was perfectly matched with using the minimum amount of reactants under very mild conditions (345 K, 2 h). The overall convenience of the process was completed by the anaerobic digestion of fibrous residues obtained from centrifugation of starting sewage scum: the final biogas resulted largely enough to sustain the heat of process. (C) 2015 Elsevier Ltd. All rights reserved.

Fat, oil and grease (FOG) recovered by the oil/water separator of a wastewater treatment plant (WWTP) were sampled, characterized, activated and converted into biofuel. Free acids (50-55%) and fatty soaps (26-32%) not only composed the main components, but they were also easily separable from the starting waste. The respective free fatty acid profiles were gas-chromatographically evaluated, interestingly verifying that free acids had a different profile (mainly oleic acid) with respect to the soapy fraction (saturated fatty acids were dominant). The inorganic composition was also determined for soaps, confirming that calcium is the most commonly present metal. The chemical activation of this fatty waste was made possible by converting the starting soaps into the respective free fatty acids by using formic acid as activator, coproducing the relevant formates. The activated fatty matter was then converted into biofuel through direct esterification under very mild conditions (345 K, atmospheric pressure) and obtaining thermodynamic conversion in less than 2 h. The process was easily scaled up, isolating at the end pure biodiesel (purity>96%) through distillation under vacuum, providing a final product conformed to commercial purposes.

RATIONALE The balance of organic nitrogen and sulfur during ozonation of organic pollutants often shows a lack of complete mineralization. It follows that polar and ionic by-products are likely to be present that are difficult to identify by liquid chromatography/mass spectrometry (LC/MS). METHODS The structural elucidation of low molecular weight organic acids arising from Uniblu-OH ozonation has been investigated by ion chromatography/electrospray tandem mass spectrometry (IC/ESI-MS/MS) employing a quadrupole time-of-flight mass spectrometer. Unequivocal elemental composition of the by-products was determined by a combination of mass accuracy and high spectral accuracy. RESULTS The employed identification strategy was demonstrated to be a powerful method of unequivocally assigning a single chemical composition to each identified compound. The exact mass measurements of [MH] ions allowed the elemental formulae and related structures of eighteen by-products to be determined confidently. The main degradation pathways were found to be decarboxylation and oxidation. The experimental procedure allowed the identification of both nitrogen- and sulfur-containing organic acid by-products arising from Uniblu-OH ozonation. CONCLUSIONS The obtained results are of environmental relevance for the balance of organic nitrogen and sulfur during the ozonation of organic pollutants due to the lack of complete mineralization of the compounds containing these atoms. Copyright (c) 2012 John Wiley & Sons, Ltd.

Interazioni meccanochimiche di minerali argillosi con inquinanti organici: strategia innovativa per la decontaminazione di siti inquinati.

The electrochemical degradation of six of the most widely used iodinated contrast media was investigated. Batch experiments were performed under constant current conditions using two DSA (R) electrodes (titanium coated with a proprietary and patented mixed metal oxide solution of precious metals such as iridium, ruthenium, platinum, rhodium and tantalum). The degradation removal never fell below 85% (at a current density of 64 mA/cm(2) with a reaction time of 150 min) when perchlorate was used as the supporting electrolyte; however, when sulphate was used, the degradation performance was above 80% (at a current density of 64 mA/cm(2) with a reaction time of 150 min) for all of the compounds studied. Three main degradation pathways were identified, namely, the reductive de-iodination of the aromatic ring, the reduction of alkyl aromatic amides to simple amides and the de-acylation of N-aromatic amides to produce aromatic amines. However, as amidotrizoate is an aromatic carboxylate, this is added via the decarboxylation reaction. The investigation did not reveal toxicity except for the lower current density used, which has shown a modest toxicity, most likely for some reaction intermediates that are not further degraded. In order to obtain total removal of the contrast media, it was necessary to employ a current intensity between 118 and 182 mA/cm(2) with energy consumption higher than 370 kWh/m(3). Overall, the electrochemical degradation was revealed to be a reliable process for the treatment of iodinated contrast media that can be found in contaminated waters such as hospital wastewater or pharmaceutical waste-contaminated streams. (C) 2014 Elsevier B.V. All rights reserved.

A combined Lewis-Bronsted acid ethanolysis of sugars was thoroughly investigated with the aim of producing ethyl levulinate (EL) in a single step. Ethanolysis carried out at 453 K for 4 h using H2SO4 (1 wt%) and AlCl3-6H(2)O(30 mol % with respect to sugars) produced a yield of 60 mol % of EL respect to glucose and starch. Such optimised conditions were positively applied directly on different food waste, preliminarily characterised and found to be mainly composed by simple (10-15%) and relatively complex sugars (20-60%), besides proteins (6-10%) and lipids (4-10%), even in their wet form. The catalytic system resulted robust enough to the point that the copresence of proteins, lignin, lipids and mineral salts not only did not negatively affect the overall reactivity, but resulted efficiently converted into soluble species, and specifically, into other liquid biofuels of different nature.

We describe a process for the selective conversion of C-6-polyols into 5-hydroxymethylfurfural (5-HMF) in biphasic systems of organic carbonate/water (OC/W), with cerium(IV) phosphates as catalysts. Different reaction parameters such as the OC/W ratio, catalyst loading, reaction time, and temperature, were investigated for the dehydration of fructose. Under the best reaction conditions, a yield of 67.7% with a selectivity of 93.2% was achieved at 423K after 6h of reaction using [(Ce(PO4)(1.5)(H2O)(H3O)(0.5)(H2O)(0.5))] as the catalyst. A maximum yield of 70% with the same selectivity was achieved after 12h. At the end of the reaction, the catalyst was removed by centrifugation, the organic phase was separated from water and evaporated in vacuo (with solvent recovery), and solid 5-HMF was isolated (purity >99%). The recovery and reuse of the catalyst and the relationship between the structure of the OC and the efficiency of the extraction are discussed. The OC/W system influences the lifetime of the catalysts positively compared to only water.

tHomogeneous aluminium species, obtained by dissolving AlCl3·6H2O into methanol, were characterisedand tested as catalysts into the direct esterification of free fatty acids with methanol. The nature andthe role of this catalyst was further investigated through ESI-MS and FTIR spectroscopy, by revealingan immediate exchange reaction between methanol and the water molecules originally bounded to thealuminium, producing a final mixed methanol-aquo-complex whose reactivity was found to be compa-rable to that of a methanolic solution of hydrogen chloride. Reaction conditions were optimised using thedesirability function applied on the response surface methodology analysis of a Box-Behnken factorialdesign of experiments. By carrying out the reaction at 72oC for 120 min and using a catalyst amount of1.5% (mol of Al respect to fatty acids), almost 94% of the starting acids were converted. At the end of thereaction, a biphasic system was obtained in which the upper methanolic phase, which contained mostof the starting catalyst, was separated from the heaviest phase, mainly composed of fatty acid methylesters. Such a distribution not only allowed the biodiesel to be easily separated, but also the catalystswere efficiently recovered and reused for at least four times, determining a total TON greater than 200,without revealing any loss of its activity.

The possibility of reusing leachate substances for agronomical purposes might be of interest, especially in arid areas when used in addition to the leachate water content. This study presents a simple procedure for the revegetation of the walls of closed landfills, reusing the leachate as a fertigant. The results demonstrated the real possibility of employing blended leachate as a fertigant for the revegetation of the walls of closed landfills. The native plants Lepidium sativum, Lactuca sativa and Atriplex halimus, which suit the local climate, were chosen for this study in Southern Italy. The methodology was structured into three phases: (i) early-stage toxicity assessment phase (apical root length and germination tests), (ii) adult plant resistance assessment phase and (iii) soil properties verification phase. The rationale of the proposed approach was first to look at the distinctive qualities and the potential toxicity in landfill leachates for fertigation purposes. Afterwards, through specific tests, the plants used were ranked in terms of resistance to the aqueous solution that contained leachate. Finally, after long-term irrigation, any possible worsening of soil properties was evaluated. In particular, the plants maintained good health when leachate was blended at concentrations of lower than 25% and 5%, respectively, for Atriplex halimus and Lepidium sativum. Irrigation tests showed good resistance of the plants, even at dosages of 112 and 133.5 mm/m2, at maximum concentrations of 25% and 5%, respectively, for Atriplex halimus and Lepidium sativum. The analysis of the total chlorophyll content and of aerial parts dried weight confirmed the results reported above. ? 2016 Springer International Publishing Switzerland.

Titanates may be selectively used as inorganic adsorbents for heavy metal ions owing to their stability andfast adsorption kinetics. Nevertheless, the synthesis of such materials usually requires extreme reactionconditions. In this work, a new titanium-based material was rapidly synthesized under mild laboratoryconditions. The obtained amorphous hydroxo titanate was tested for heavy metal sorption through kineticand equilibrium batch tests, which indicated that the new material had high adsorption rates andadsorption capacities towards Cu2+, Ni2+ and Pb2+ ions. Adsorption kinetics were pseudo-second order,and equilibrium data fitted the Langmuir isotherm model. The calculated maximum adsorption capacitiesof Cu2+, Ni2+ and Pb2+ in deionized water were around 1 mmol g-1, and they decreased for Cu2+ andNi2+ in the presence of Na+, Ca2+ and Mg2+ ions, whereas the alkali metal ions did not influence Pb2+uptake. The efficiency of adsorption and recovery of lead ions were evaluated through column dynamictests, by feeding the column with groundwater and tap water spiked with Pb2+. The high performance ofthe hydroxo titanate over several cycles of retention and elution suggested that the product is potentiallyuseful for the solid phase extraction of lead at trace levels in natural water samples, with potential use inmetal pre-concentration for analytical applications

Present technologies for wastewater treatment do not sufficiently address the increasing pollution situation of receiving water bodies, especially with the growing use of personal care products and pharmaceuticals (PPCP) in the private household and health sector. The relevance of addressing this problem of organic pollutants was taken into account by the Directive 2013/39/EU that introduced (i) the quality evaluation of aquatic compartments, (ii) the polluter pays principle, (iii) the need for innovative and affordable wastewater treatment technologies, and (iv) the identification of pollution causes including a list of principal compounds to be monitored. In addition, a watch list of 10 other substances was recently defined by Decision 2015/495 on March 20, 2015. This list contains, among several recalcitrant chemicals, the painkiller diclofenac and the hormones 17 beta-estradiol and 17 alpha-ethinylestradiol. Although some modern approaches for their removal exist, such as advanced oxidation processes (AOPs), retrofitting most wastewater treatment plants with AOPs will not be acceptable as consistent investment at reasonable operational cost. Additionally, by-product and transformation product formation has to be considered. The same is true for membrane-based technologies (nanofiltration, reversed osmosis) despite of the incredible progress that has been made during recent years, because these systems lead to higher operation costs (mainly due to higher energy consumption) so that the majority of communities will not easily accept them. Advanced technologies in wastewater treatment like membrane bioreactors (MBR) that integrate biological degradation of organic matter with membrane filtration have proven a more complete elimination of emerging pollutants in a rather cost- and labor-intensive technology. Still, most of the presently applied methods are incapable of removing critical compounds completely. In this opinion paper, the state of the art of European WWTPs is reflected, and capacities of single methods are described. Furthermore, the need for analytical standards, risk assessment, and economic planning is stressed. The survey results in the conclusion that combinations of different conventional and advanced technologies including biological and plant-based strategies seem to be most promising to solve the burning problem of polluting our environment with hazardous emerging xenobiotics.

Fat, oil and grease produced by oil/water separation at the wastewater treatment plant of Bari West (Southern Italy) were taken, characterized and converted. After chemical activation of this fatty fraction, with the aim of converting the starting calcium soaps into the respective free fatty acids, a direct esterification was carried out under very mild conditions. Working at 345 K under atmospheric pressure, the thermodynamic conversion (more than 90%) of the free fatty acids into the respective methyl esters was obtained in less than 2 h, by using AlCl3·6H2O as catalyst. Fundamental parameters, such as kinetic and equilibrium constants at different temperatures and activation energy correlated to the use of this catalyst, were also calculated. The biodiesel was purified with a distillation under vacuum, providing a final product conformed to the EN14214 requirements. The convenience of the overall process in terms of costs (0.45 EUR L-1) and specific thermal energy supply (5.02 MJ KgFAMEs-1) make such a process a really sustainable and effective example of valorization of a waste.

To prevent over-exploitation of global fish stocks by the aquaculture industry, interest is growingin the identification of nontraditional species with potential value as fish feed. In this study,we investigated the biochemical composition of the polychaete Sabella spallanzanii . Its elementalcomposition, gross protein and proximate composition, amino acid composition, total lipid andfatty acid content, glycosaminoglycan (GAG) content and the extent of polychlorinated biphenylcontamination were determined over an annual cycle. Sabella spallanzanii showed particularlyhigh gross protein (54.8±5.8%) and gross energy (4.89±0.5 kcal/g) content. All samples had highconcentrations of Na, K, Ca, and Cl. Saturated fatty acids were higher than monounsaturated andpolyunsaturated ones. A low ?-6/?-3 ratio (1.7) was recorded. Our results suggest that S. spallanzaniican be used as a dietary supplement for farmed fish. The high concentrations of certain amino acidsthat improve potential palatability for many farmed fish species suggest that S. spallanzanii extractscan be used in artificial fish diets as an attractant. A further original aspect highlighted by this studyis the high concentration of GAGs, which are useful in pet nutrition and also in the nourishment offarmed fish with a partially cartilaginous skeleton.

An on-line solid phase extraction coupled with high-performance liquid chromatography in tandem with mass spectrometry (on-line SPE/HPLC/MS-MS) method for the determination of five microcystins and nodularin in surface waters at submicrogram per liter concentrations has been optimized. Maximum recoveries were achieved by carefully optimizing the extraction sample volume, loading solvent, wash solvent, and pH of the sample. The developed method was also validated according to both UNI EN ISO IEC 17025 and UNICHIM guidelines. Specifically, ten analytical runs were performed at three different concentration levels using a reference mix solution containing the six analytes. The method was applied for monitoring the concentrations of microcystins and nodularin in real surface water during a sampling campaign of 9 months in which the ELISA method was used as standard official method. The results of the two methods were compared showing good agreement when the highest concentration values of MCs were found. [Figure not available: see fulltext.]