A combination of a parallel fracture model with the PHREEQC-2 geochemical model wasdeveloped to simulate sequential flow and chemical transport with reactions in fracturedmedia where both laminar and turbulent flows occur. The integration of non-laminar flowresistances in one model produced relevant effects on water flow velocities, thus improvingmodel prediction capabilities on contaminant transport. The proposed conceptual modelconsists of 3D rock-blocks, separated by horizontal bedding plane fractures with variableapertures. Particle tracking solved the transport equations for conservative compounds andprovided input for PHREEQC-2. For each cluster of contaminant pathways, PHREEQC-2determined the concentration for mass-transfer, sorption/desorption, ion exchange, mineraldissolution/precipitation and biodegradation, under kinetically controlled reactive processes ofequilibrated chemical species. Field tests have been performed for the code verification. As anexample, the combined model has been applied to a contaminated fractured aquifer ofsouthern Italy in order to simulate the phenol transport. The code correctly fitted the fieldavailable data and also predicted a possible rapid depletion of phenols as a result of anincreased biodegradation rate induced by a simulated artificial injection of nitrates, upgradientto the sources.

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).

The degradation of two of the most frequently used UV-filters was investigated through microcosm studies. Marinesediments sampled fromtwo sites in Italy (La Spezia harbour and Sarno river estuary, S1 and S2 respectively)were used to set up aerobic and anaerobic sets of reactors. The sediments were spiked with a methanol solutionof 3-(4-methylbenzylidene)camphor (4-MBC) and 2-ethylhexyl 4-(dimethylamino)benzoate (EH-DPAB), atconcentrations of either 25 or 50 mg kg-1 each. Methanol (6.3 g/L) also served as an organic amendment andgrowth substrate for improving microbial activity.Monitoring of the biotic and abiotic degradation of the selectedcontaminants over 16 months revealed that 4-MBC biodegradationwas very slow and incomplete,whereas over90% of EH-DPAB was degraded both in the aerobic and the anaerobic reactors by the natural microbial communitiesof both sediments. Repeated spikes of EH-DPAB were followed by complete decay, characterised by firstorderkinetics. The calculated kinetic rate constants under aerobic and anaerobic conditions were similar. In reactorsinoculated with the S1 sediment the degradation rate constants progressively increased after each spike,up to the value of 0.039 d-1. For the S2 sediment the rate constant was around 0.020 d-1 throughout the durationof the experiment. Mass spectrometry analysis of sediment extracts allowed detection of potential transformationproducts of EH-DPAB and 4-MBC. Moreover, the natural microbial community of the sediments wasstudied using the CAtalyzed Reporter Deposition Fluorescence In Situ Hybridization (CARD-FISH) both in the initialsediments and after degradation under aerobic and anaerobic conditions.

The biodegradation potential of marine sediments towards two selected UV-filters was tested through a laboratory investigation. Sediments collected from two locations in Italy were spiked with 3-(4-methylbenzylidene)camphor (4-MBC) and 2-ethylhexyl 4-(dimethylamino)benzoate (EH-DPAB), and used to set up eight microcosms that were operated under either aerobic or anaerobic conditions. UV-filters concentration in the sediment was monitored over 360 days. Results showed that native microbial communities of both sediments were able to perform the complete removal of EH-DPAB, whereas 4-MBC was scarcely affected by biodegradation. Degradation kinetics of EH-DPAB was first-order, with kinetic rate constants around 0.02 d-1 for both sediments under both aerobic and anaerobic conditions. Microbiological characterisation of microcosms showed that the composition and structure of the sediment microbial communities changed after the different treatments with respect to the native microbial population.

Fenton oxidation of the nonionic surfactant Brij 35 was enhanced by the effect of 1,4-hydroquinone adsorbed on granular activated carbon (GAC). The procedure allowed 90%-94% surfactant removal after 24 h at pH= 2.7-3.0, using 97mg g- 1 of hydroquinone adsorbed on GAC and concentrations of surfactant, H2O2, and iron (either Fe2 + or Fe3 + ) of, respectively, 1300, 450, and 9mg L- 1. In the absence of carbon and hydroquinone, and with the same concentration of H2O2, conventional Fenton process required 300mg L- 1 of Fe(II) to obtain 85% removal of Brij 35. Quinone-loaded carbon was effectively recycled until surfactant removal decreased to 50%-60%. Only 3% of hydroquinone was desorbed from GAC to the aqueous solution, and about 40% of the dissolved fraction was degraded to low-molecular-weight organic acids. This is the first description of a Fenton process performingthe recycling of a redox-active organic compound adsorbed on GAC, with the aim of decreasing the amount of iron salt utilized in the conventional Fenton reaction.

Batch and column tests were conducted to compare the efficiencies of three Fenton-like systems in the degradation of chlorobenzene. In the investigated systems, iron powder was the source of Fe2+ ions, and either Fe 3+ or Cu2+ were added in order to enhance the degradation process. Optimum pH and concentrations of Fe 3+ , Cu2+ and hydrogen peroxide were assessed by treating synthetic chlorobenzene solutions both in batch and in column mode, thus achieving the minimum residual concentration of chlorobenzene. Optimum conditions assessed by means of column tests were then applied to column treatment of real chlorobenzene-contaminated groundwater. Results showed that,when the TOC content of water was above 12 mg L-1, the performance of the Fe0/H2O2 system was enhanced by the addition of Fe3+, leading to 10-2 ?g L-1 of residual chlorobenzene.

An environmentally friendly proceduresuitable to restore a protected area was evaluated atlaboratory scale. Soil contaminated by high molecularweight (C>10) aliphatic hydrocarbons and by chromiumwas withdrawn from the study site and a qualitativestudy of soil hydrocarbon components was first performedin order to assess the potential source ofcontamination. To this aim, a number of characteristicdiagnostic ratios of hydrocarbon components werederived by processing chromatographic data, and wereused as indicators for distinguishing anthropogenic fromnatural hydrocarbons. Then, the efficiency of landfarmingfor soil remediation was tested by comparingthe effect of a few selected amendments and by monitoring the fate of chromium. Soil microbialabundance and activity were also evaluated. Resultsshowed that soil hydrocarbons were mainly of anthropogenicorigin and land treatment allowed effectivedegradation by native microbial populations even in theabsence of amendments. The investigated procedureshad no effect on the mobilisation of chromium thatremained in its stable form of Cr(III). Conventional landtreatment may therefore be an effective and safeprocedure for the removal of hydrocarbons even in thepresence of chromium, and may be applied to areaswhere low-impact procedures are strictly required.

The photochemical degradation of two azo and two anthraquinonic dyes was performed using potassiumperoxymonosulphate (Oxone) activated by UV radiation. The fast decolourization of all dyes wasobserved within 6 min of UV irradiation, with corresponding dye decays higher than 80%. The kinetic rateconstants of the dyes' decay were determined, along with the energetic efficiency of the photochemicaltreatment, taking into account the influence of a few anions commonly present in real wastewaters (i.e.,chloride, nitrate, carbonate/bicarbonate and phosphate ions). Chloride and carbonate/bicarbonate ionsenhanced dye degradation, whereas phosphate ions exerted an inhibitory effect, and nitrates did nothave a predictable influence. The dye decolourization was not associated with efficient mineralization, assuggested by the lack of a significant total organic carbon (TOC) decrease, as well as by the lowconcentrations of a few detected low molecular weight by-products, including nitrate ions, formaldehydeand organic acids. High molecular weight by-products were also detected by mass spectrometry analysis.The investigated process may be proposed as a convenient pre-treatment to help dye degradation inwastewater during combined treatment methods.

Two sets of soil lysimeters were amended with solid and liquid olive mill wastes and the composition ofleachate was analysed. Five treatments were carried out using: olive mill wastewater (OMW) at twodifferent rates (80 and 320 m3/ha); OMW pre-treated by catalytical digestion with MnO2; compost obtainedby exhausted olive pomace; freshwater as the control. Electric conductivity, pH, potassium, totalpolyphenols and nitrates were monitored in the leachate as indexes of potential groundwater contamination.The study demonstrated that the impact of all the selected amendments on groundwater was theminimum. OMW was safely applied to soil even at four times the rate allowed by the Italian law, and pretreatmentby catalytical digestion was not necessary to further reduce the impact on groundwater. Theapplication of olive pomace compost was equally safe.

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