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Biomasses are materials of organic origin that can be used for the production of energy. Among the renewable energy sources, a prominent role is played by woody biomass, which can be retrieved from existing forests or plantations governed in short or middle rotation coppice, the so-called Short and Medium Rotation Forestry. The main environmental benefit resulting from the use of wood biomass consists in the fact that the amount of carbon dioxide released during their combustion process is the same as that absorbed during the development phase. Here, we propose a procedure to manage the traceability of short biomass chains and to schedule the activities for mobile forest construction sites using free and open-source GIS technologies. Firstly, we created a spatial DB to manage the areas where the cutting and logging activities are performed. Then, we overlapped the boundaries of areas with the cadastral sheets to ensure the biomass comes from short chain, i.e., within the range of 70 km from the position of the central. To plan the number of working days required and make an estimation of the production, the total area of the lots, the land clearing, and the net area were calculated. Finally, depending on the characteristics of wooded areas, the type of system to be used for the business of cutting and logging was evaluated. This work demonstrates how GIS allows a fast traceability of short biomass chains and an estimation of the production by improving the efficiency and effectiveness of biomass resource assessment.

Mt. Etna, the largest volcano in Europe, is periodically interested by intensive eruption activity sometimes causing environmental problems for the neighbouring urban areas such as Catania. The volcanic ash deposited on the roads is classified as waste (code 20 03 03 – municipal waste from European Waste Catalogue - EWC). In this work, with the aim to transform waste materials into useful product, two samples of ashes resulting from different explosive activities were treated by hydrothermal aging with distilled water and seawater. The results showed that the hydrothermal process determined mineralogical and magnetic changes in volcanic ashes. The data in fact indicated that X-type zeolite and sodalite were formed at 45, 60 and 70 °C of aging temperature. Moreover, magnetic characterization suggests an evolution of ferromagnetic materials to antiferromagnetic ones during zeolite formation. The presence of these new magnetic phases was responsible for the variety of magnetic behaviour. The applicability of obtained zeolite as novel adsorbent material in the field of water treatment was also evaluated. Batch adsorption experiments were carried to assert the adsorption capacity of novel synthetized zeolite in removing cesium ions from aqueous solutions thus confirming a possible End-of-Waste alternative.

This work aims to investigate the simultaneous mercury (Hg) and polycyclic aromatic hydrocarbons (PAHs) removal from seabed sediments by means of 2.45 GHz microwave irradiation with chemical enhancers. Decontamination kinetics were assessed applying Tween® 80, methylglycinediacetic acid (MGDA) and citric acid as enhancers. Results clearly showed that sediment dielectric features allowed a large conversion of microwaves (MW) irradiated energy into temperature increase (405 °C within 7 min). The combined use of Tween® 80 and MGDA in a 650 W MW irradiation treatment brought a final residual Hg concentration of 2.2 mg kg−1, whereas Tween® 80 and citric acid allowed a residual concentration less than 1 mg kg−1 (R = ~ 99%). Lower residual concentration was found also for total PAHs (

This review highlights that microwave (MW) heating can be largely considered advantageous for environmental applications. MW has been largely proposed for the processing of sludge or radioactive and toxic wastes including hospital waste, tyres and industrial scores. Researchers demonstrated that MW heating is an eco-friendly technology for waste detoxification because of higher sustainability and effectiveness as complete detoxification process if compared with established techniques such as incineration or conventional pyrolysis. Experimental data demonstrated that MW heating could be also considered as a preferable choice compared with conventional chemical-physical or heating techniques in treating contaminated soils when soils present natural or enhanced high dielectric features. Analogously, for sediment decontamination processes, only conventional thermal treatments can be similarly effective as MW heating, but requiring high temperatures and costs. Undoubtedly, MW-absorber and irradiated matrix heavily affect the MW effectiveness and energy requirements. In general, the main advantages of MW are very rapid process, selective and environmentally sustainable. This depends on the principle of dielectric heating that allows the activation of effective removal mechanisms, namely selective heating and contaminant stripping by water distillation. However, despite the demonstrated possibility of combining eco-friendly with very high removals, the growth of industrial MW applications is still limited due to the lack of several information, which, at the moment represents difficult challenges. In fact, literature mainly relies on lab-scale experiments, and extending the obtained achievements to full-scale still faces to many problems. This still makes MW rarely applied to real practises. Material characterisation, scaling-up, pilot, modelling, design and demonstration studies are strongly desired to bridge the gap between existing literature and full-scale applications, and moving to industrial/production scale. Then, despite a change of approach being observed especially in the last three years, interdisciplinary future research is strictly required in order to exploit the full potential of MW-techniques.

This study investigates the occurrence of airborne asbestiform fibers released in indoor ambient due to the use of asbestos naturally contaminated water. Some experiments employed a laboratory physical model using an ultrasonic humidifier charged with contaminated groundwater. Other experiments were carried out at full scale to assess the release of asbestiform fibers during showering. Obtained results show that the concentration of the airborne asbestiform fibers released in the bathroom during showering is higher than the limit value set by the European and Italian Regulations, while the concentration of fibers released by the humidifier is much lower. However, it is noteworthy that the use of the humidifier at high exposure time results in similar health risk. Strong correlations were found between the concentration of the airborne asbestiform fibers and a novel surrogate parameter (i.e. the exposure-specific-water-consumption). These correlations can be used to monitor the asbestiform fibers concentration at varying operating conditions and therefore, to control the resulting health risk.

The potential ability of microwave heating (MWH) for the remediation of marine sediments affected by severe hydrocarbon (HC) contamination was investigated. Decontamination effectiveness and environmental sustainability through a comparative Life Cycle Assessment (LCA) were addressed. Main results revealed that the application of a 650-W MWH treatment resulted in a rapid (15 min) HC removal. A citric acid (CA) dose of 0.1 M led to enhanced-HC removals of 76.9, 96.5 and 99.7% after 5, 10 and 15 min of MW irradiation, respectively. The increase in CA dose to 0.2 M resulted in a shorter successful remediation time of 10 min. The exponential kinetic model adopted showed a good correlation with the experimental data with R 2 values in the 0.913–0.987 range. The nature of the MW treatment was shown to differently influence the HC fraction concentration after the irradiation process. Achieved HC removals in such a short remediation time are hardly possible by other clean-up techniques, making the studied treatment a potential excellent choice. Removal mechanisms, which allowed the enhanced-MWH to operate as a highly effective multi-step technique (pure thermal desorption + chemical washing), undoubtedly represent a key factor in the whole remediation process. The LCA highlighted that the MW technology is the most environmentally sustainable alternative for sediment decontamination applications, with a total damage, which was 75.74% lower than that associated with the EK (0.0503 pt).

The aim of this work was to demonstrate the concept of a combined MW-UV-A treatment for the successful remediation of PAH-contaminated marine sediments and the successive photo-degradation of the generated vaporized organic compounds, entrapped in the exhaust gas line. The role of Tween 80 and citric acid as degradation enhancers was also investigated, considering variable MW/UV operating conditions and irradiation times. Main results revealed a very rapid sediment temperature increase during MW heating (up to ∼380 °C), due to the dielectric properties of both sediment minerals and adsorbed PAHs, which highlighted their great ability to passively convert MWs into heat and in turn allow a very effective PAH-decontamination. PAH removal was higher than 85% after 1-min MW irradiation mainly due to “selective heating” and contaminant stripping removal mechanisms. Longer times led to the total removal of the contaminants. The addition of enhancing agents showed an improvement of the MW performance in the order: MW

The elimination of organic carbon, nitrogen, five emerging organic contaminants (EOCs) and fluorescence signature was evaluated in two treatment lines comprising different constructed wetland (CW) configurations: (i) partially saturated vertical subsurface flow (SVF) wetland (treatment line 1) and (ii) unsaturated vertical subsurface flow (UVF), horizontal subsurface flow (HF) and free water surface (FWS) wetlands in series (treatment line 2). Results showed important differences between the different CW configurations. The highest removal of BOD5 (81%), COD (67%), TOC (72%) and fluorescing organic matter were observed in the UVF wetland, whereas the HF and FWS wetlands were the most efficient units for total nitrogen removal (60 and 69%, respectively). The SVF wetland showed a greater performance in the reduction of total nitrogen than the UVF bed (52 vs. 35%). In addition, the SVF wetland exhibited a higher removal of the EOCs caffeine (95 vs. 90%), trimethoprim (99 vs. 87%) and sulfamethoxazole (64 vs. 4%), as opposed to DEET (34 vs. 63%), whose removal was superior in the UVF unit. Sucralose was negligibly removed in all the CWs. PARAFAC analysis of fluorescence measurements revealed that the proteinaceous tryptophan-like fluorescent component was the most highly removed one in all the investigated CWs (>28%) and, particularly, in the UVF wetland (66%), whereas humic and fulvic-like components resulted recalcitrant to decomposition. Increases of fluorescence intensities were often observed for fulvic-like substances in CWs operating with saturation of the bed, and these were particularly relevant in the SVF unit. Finally, important correlations (r > 0.7) between the tryptophan-like fluorescent component and the wastewater quality parameters COD and BOD5 suggest fluorescence spectroscopy as an useful monitoring tool for water treatment efficiency in CW systems.

In this study, a new enhanced MW heating treatment using glycerol was proposed and investigated in the remediation of marine sediments highly contaminated with hydrocarbons. The heating and contaminant removal performance of different treatments using varying glycerol doses were compared. The results showed that the addition of glycerol in sediments largely promoted the MW absorbing performance that corresponded to a large increase in temperature (up to ∼120 °C) with a maximum sediment temperature of 342 °C. This allowed much faster contaminant removal kinetic to be obtained. A glycerol dose of 5% led to drastically lowered contaminant residual concentrations of 6454 (R = ∼81%), 770 (R = ∼98%) and 12 (R > 99%) mg kg −1 after 3, 5 and 10 min, respectively, demonstrating that ∼5 min were sufficient to reach the regulatory remediation target. A further dose increase (10%) led to a required time of 3 min (R > 99%), which corresponded to almost half of the MW energy required respect to the unenhanced MW. The main advantage of MW/glycerol treatment is the possibility to obtain a very rapid and effective decontamination process potentially reducing energy costs, also in the case of a very high initial hydrocarbon concentration, without producing additional by-products (respect to MW alone), which in some cases can be toxic. A comparison with other available clean-up alternatives revealed that literature does not report similar rapid and at the same time effective treatments for hydrocarbon-contaminated sediments.

The aim of this work was to investigate Hg removal ability of a novel microwave heating (MWH) treatment for marine sediment remediation enhanced by the application of several agents, biodegradable complexing agent (methylglycinediacetic acid, MGDA), surfactant (Tween® 80), and citric acid. Main results revealed that MWH allowed a very rapid heating (∼450 °C in 7 min) of the irradiated medium. However, without the addition of enhancing agents, a maximum Hg removal of ∼72% can be achieved. The application of MGDA led to a higher contaminant removal of ∼87% (residual concentration = 5.4 mg kg −1 ). For the treatment including the simultaneous addition of both chelating agent and surfactant, their synergetic action and stripping processes resulted in a very high Hg removal of ∼99% for an irradiation time of 7 min, corresponding to a residual concentration of 0.56 mg kg −1 , which is lower than the Italian regulatory limit of 1 mg kg −1 . The use of citric acid resulted in a shortening of the removal kinetics, which allowed the successful application of a shorter remediation time of 5 min. The observed strong passive ability of sediments to convert a microwave irradiation energy into a rapid and large temperature increase undoubtedly represents a key factor in the whole remediation process, making the studied treatment an excellent choice. Kinetic data are suitable for a preliminarily assessment of the effectiveness of clean-up activities, and as basis for future scaling-up studies on MWH of Hg-contaminated sediments.

Localization and quali-quantitative characterization of radionuclide-contaminated soils are essential for healthcare and remediation activities. However, characterization activities are at the moment mainly based on very complex activities, generally dangerous for workers’ health. Unmanned aerial vehicles (UAVs) can be considered for this purpose, but the absence of data does not permit their use for a quantitative analysis. The main goal of this work is to obtain scientific information for successfully using UAVs in quali-quantitative characterization activities. The influence of the main flight UAV condition parameters on the detection efficiency and minimum detectable activity (MDA) concentration was assessed at lab-scale, considering 241Am and 152Eu as simulated soil contaminants. Obtained data were compared with reference to clearance levels. Specifically, the altitude (h) and inclination (θ) with respect to the soil surface of a small size γ-ray semiconductor CdTe detector and detection time were investigated as flight parameters. h and θ were adopted in the range 0–70 cm and 0°–60°, respectively. Main results reveal that in the case of 241Am contamination, a duration time of about 13 and 20 min is required for an altitude of 60 and 70 cm, respectively, if an inclination of zero is considered, whereas inclinations higher than 15° lead to much longer times, up to 40 min. In the presence of 152Eu, results reveal a more marked influence of the variables h and θ on the minimum detection time, with values higher for 241Am. In terms of MDA, in the case of 241Am, all the concentration values, with the exception of the highest θ investigated (60°), are below the Italian regulatory limit for altitudes lower than 35 cm and a detection time of 30 min. Higher h up to 50 cm can be considered, reducing the inclination up to 0°, whereas even higher altitudes make the detection of 241Am not possible. On the other hand, for 152Eu, the observed MDA values always make the contaminant detection possible. All achievements and the calculated fitting parameters are useful preliminary data in the quantitative characterization of soil surface contamination, representing a valuable tool in knowing the soil surface γ-ray activity of 241Am and 152Eu for each given detected value. In general, obtained results will allow a better understanding of the technique limits and operating methods required for characterization activities by UAVs with vertical take-off and landing system.

This study investigated the applicability of fluorescence indexes based on the interpretation of excitation emission matrices (EEMs) by PARAFAC analysis and by selecting fluorescence intensities at a priori defined excitation/emission pairs as surrogates for monitoring the behavior of emerging organic compounds (EOCs) in two catchment basins impacted by wastewater discharges. Relevant EOC and EEM data were obtained for a 90 km stretch of the Simeto River, the main river in Sicily, and the smaller San Leonardo River, which was investigated for a 17 km stretch. The use of fluorescence indexes developed by these two different approaches resulted in similar observations. Changes of the fluorescence indexes that correspond to a group of humic-like fluorescing species were determined to be highly correlated with the concentrations of recalcitrant contaminants such as sucralose, sulfamethoxazole and carbamazepine, which are typical wastewater markers in river water. Changes of the fluorescence indexes related to tyrosine-like substances were well correlated with the concentrations of ibuprofen and caffeine, anthropogenic indicators of untreated wastewater discharges. Chemical oxygen demand and dissolved organic carbon concentrations were correlated with humic-like fluorescence indexes. The observed correlations were site-specific and characterized by different regression parameters for every collection event. Caffeine and carbamazepine showed correlations with florescence indexes in the San Leonardo River and in the alluvial plain stretch of the Simeto River, whereas sucralose, sulfamethoxazole and ibuprofen have always been well correlated in all the investigated river stretches. However, when data of different collection events from river stretches where correlations were observed were combined, good linear correlations were obtained for data sets generated via the normalization of the measured concentrations by the average value for the corresponding collection event. These results show that fluorescence based indexes can be used to monitor the behavior of some trace organic contaminants in wastewater impacted rivers and to track wastewater discharges in streams and rivers.

In this work, γ-ray shielding, unconfined compressive strength (UCS) and contaminant immobilisation performances of barite (Ba)-Portland cement (PC) grouts in Stabilisation/Solidification (S/S) treatment of 232 Th-contaminated soils were studied. This is with the view to investigating the influence of the Ba and grout (G) content used in S/S mixes. Results show that the replacement of PC with Ba (up to 50%) leads to a significant increase, up about 2-fold, of the γ-ray shielding performance, but a higher Ba content in Ba-PC mixture decreases the S/S shielding performance due to the reduction of the final density of the S/S products, caused by the inhibition of cement hydration process. The highest γRS index of ~ 37% was found in the case of the maximum G to soil content of 50%. Ba and G content significantly influences the UCS performance of the S/S products. A marked UCS increase up to ~ 20% was found replacing PC with Ba with a Ba content of 50%. All the investigated S/S samples have UCS values that fulfil the quality criteria requirements. The use of Ba in PC grout allows the achievement of the almost total 232 Th-immobilisation, even in extreme-acidic environment conditions (pH: 3, 1), also due to the Ba fine texture and high surface area able to reduce the final porosity of S/S products. Overall, the γRS index, observed jointly with the excellent immobilisation performances, reveals the mixture PC:Ba = 1:1 with S:G = 2:1 as the optimal choice in order to achieve the remediation targets and, at the same time, limit the costs, highlighting the possibility to successfully treat real 232 Th-contaminated soils. However, a S:G = 1:1 can be considered if a higher γ-ray shielding of 37% is required.

The limits of microwave (MW) heating in situ application for the remediation of hydrocarbon-polluted soils have been investigated by means of a dedicated simulating model. A computer code was expressly developed and applied to simulate the physical phenomena induced by a MW treatment. MW process was modelled by means of the mono-dimensional transient equations of energy, taking into account the interaction between the electromagnetic field and soil and conductivity phenomena. The model was validated by comparison with experimental results from lab-scale activities. Simulations investigated the influence of soil texture and moisture and operating conditions on electric field penetration into the soil and inducted soil temperature profiles. Main results indicate that all investigated parameters significantly influenced the effectiveness of the heating process. In generally, the sandy soil appeared to be more penetrable by MWs respect to the clayey one and higher electric field and soil temperature values were found for the sandy soil with the lower water content. Results also revealed that, for the successful remediation of a clayey soil, a maximum distance of 76 cm should be considered when applying an incident electric field of 1000 V m− 1 for 15 days, whereas a higher distance of 101 cm can be taken in consideration in the case of sandy soil. A further slight distance increase can be achievable in the case of lowest-moisture soil (5%). Overall, the general performance of the treatment can be greatly improved by increasing the incident electric field to a value 1500 V m− 1. In this case, a 15-day heating of a sandy soil led to the maximum distance calculated of 145 cm. Obtained results are of scientific and practical interest and represent the basis for further technical, energy and economic studies, useful to better define the limits of the in situ MW treatment real applicability. The proposed model, giving good prediction of the experimental data for electric field and soil temperature variation, represents a powerful and suitable tool to predict the impact of operating conditions on the effectiveness of the MW techniques.

The main objective of this study was to compare the energy cost-effectiveness of two innovative techniques, namely microwave (MW) heating and electrokinetic (EK) decontamination for the successful remediation of highly Hg-contaminated marine sediments from Augusta Bay (Sicily, Italy). Bench-scale experiments were conducted and obtained results were used to elaborate energy and economic considerations aimed at selecting the most effective and economic approach. Results revealed that without any appropriate conditioning agents, very poor contaminant mobilization can be achieved by EK due to the high percentage of carbonates, as sediment mineral, and high organic matter and sulphides. The best Hg-removal ( ∼ 71% in 400 h) was achieved using both methylglycinediacetic acid (MGDA) and polyoxyethylene (20) sorbitan monooleate (Tween 80) as processing agents. Related Hg residual concentrations exceed the desired regulatory limit of 1 mg kg−1 for Augusta Bay. Simulated MW heating showed the achievement of a very rapid sediment temperature increase ( ∼ 64 °C min−1, maximum ∼ 450 °C), mainly due to the mineral composition of the sediments and their high salinity. This jointly with the addition of both MGDA and Tween 80, led to a very low residual Hg concentration of 0.56 mg kg−1 (R = ∼ 99%) after 7-min treatment. Calculations from energy and economic analysis revealed that a specific energy consumption of 6.73 kWh ton−1, which corresponds to an energy cost of 0.81 € ton−1, is required for the EK, whereas slightly higher values (32.97 kWh ton−1 and 3.96 € ton−1) were assessed for MW heating. Therefore, the higher Hg-removal obtainable in such a short remediation time by MW heating along with its with other advantages offset a low specific energy cost increase, making this technique a preferable choice for the remediation of Hg-contaminated marine sediments such as those present in Augusta Bay.

Membrane bioreactor (MBR) technology offers several advantages compared to the conventional wastewater treatment plants (CAS: conventional activated sludge) but also some disadvantages. Both advantages and disadvantages have implications for capital and operational costs. Therefore, the present chapter illustrates data from literature on costs for MBR and CAS. A comparison of such costs is also presented to assess the feasibility of the MBR for wastewater reclamation. The results obtained show that both capital costs (CAPEX) and operation and maintainance costs (OPEX) for MBR may be similar to those reported for CAS with tertiary treatment. A huge variability of CAPEX and OPEX, however, have been observed in the literature. Such variation depends on the design, management, and cost of the membranes. Since the purchase cost of the membranes has lowered in the last years, such reduction could improve the feasibility of MBR plants. Furthermore, the novel technology for membrane production and management (e.g., fouling control) as well as for process control (e.g., real-time monitoring) may help to optimize the operating conditions and, in turn, reduce the OPEX of MBR. Since municipal wastewater reclamation and reuse will play a major role in the future, commitment of MBR plants is expected to increase in the civil market.

The present study evaluates the concept of permeable reactive barrier (PRB) coupled with microwaves (MWs) as in situ-regenerating technology with focus on Cs-contaminated water. Experimental and modelling results data from batch and column tests were carried out, evaluating several chemical-physical and environmental parameters. Main results showed a very rapid increase in GAC temperature during MW irradiation up to ∼680 °C. This highlights the GAC strong ability to transform MW power into heat due to GAC excellent dielectric properties (e′ = 13.8). Physical characterization revealed that GAC pore volume and specific surface area change with the number of regeneration cycles. GAC regeneration efficiency variation reflects this behaviour with a maximum value of ∼112% (5th cycle). The final GAC weight loss of ∼7% further demonstrates GAC life span preservation during MW irradiation. Results from column tests confirms that GAC can be regenerated by MW also in dynamic condition, due to sublimation/vaporization and vapour stripping Cs removal mechanisms and that the regeneration effectiveness is time-dependent. The breakthrough curve shape confirms significant benefits from MW irradiation. Overall, obtained finding demonstrated the feasibility of the proposed concept, also providing essential data to guide its scaling-up application.

In this study, a hydrocarbon-contaminated marine sediment was treated applying ex-situ thermal desorption (ESTD) at bench-scale. Temperatures up to 280 °C and heating times (t) in the 5–30 min range were investigated. Results revealed that temperatures in the range 200–280 °C led to Total Petrol Hydrocarbon (TPH)-removal efficiency (RE) from 75 to 85% (t = 10 min). The maximum RE of 89% was obtained at 200 °C for 30 min. However, a shorter remediation time of 5 min (or lower temperatures of 160 and 180 °C with longer times) is needed to reach the TPH standard limit. Data also demonstrated the selectivity of the treatment in TPH fraction removal. The modelling of the TPH removal kinetics and desorption isotherm jointly with activation energy calculation (>30 kJ mol−1) indicated that ESTD process is quite unfavorable for marine sediments. This is due to the fact that ESTD is regulated by chemisorption processes and occurred in two distinct TPH removal phases: evaporation and boiling vaporization. This depends on the strong affinity of the TPH with the fine sediment particles, as well as on the high initial water, salinity, organic matter and sulfides content. However, the comparison between alternative processes has shown that ESTD is the most feasible treatment process for TPH-contaminated marine sediment remediation. Obtained results also add relevant information that can be used as a basis for future scaling-up investigations of ESTD for hydrocarbon-contaminated marine sediments.

Data presented in this article show the extent of the inner filter effect (IFE) in fluorescence measurements of wastewater and wastewater-impacted surface water samples. Particularly, data show the effectiveness of a commonly used method for IFE correction based on UV absorbance measurement to reinstate the linearity of the relationship between fluorescence intensities and absorbance values. Data report also the effect of nitrates in fluorescence measurements of wastewater samples. Finally, data presented in this work show the effect of total suspended solids (TSS) in the UV absorbance and fluorescence measurements of different waters. Particularly, data describe the TSS effect in fluorescence intensities acquired at different pairs of excitation-emission wavelengths, and in waters with different TSS concentration. Data of this article are related to the publication “M. Sgroi, E. Gagliano, F.G.A. Vagliasindi, P. Roccaro, Inner filter effect, suspended solids and nitrite/nitrate interferences in fluorescence measurements of wastewater organic matter, Sci. Total Environ., In press” [1]. Raw data are available in a public repository ( https://doi.org/10.17632/4zss49jycj.1 ).

This work critically compared the removal of fluorescing PARAFAC components and selected pharmaceuticals (carbamazepine, fluoxetine, gemfibrozil, primidone, sulfamethoxazole, trimethoprim) from a tertiary wastewater effluent by different UV- and ozone-based advanced oxidation processes (AOPs) operated at pilot-scale. Investigated AOPs included UV/H2O2, UV/Cl2, O3, O3/UV, H2O2/O3/UV, and the new Cl2/O3/UV. AOPs comparison was accomplished using various ozone doses (0–9 mg/L), UV fluences (191–981 mJ/cm2) and radical promoter concentrations of Cl2 = 0.04 mM and H2O2 = 0.29 mM. Chlorine-based AOPs produced radical species that reacted more selectively with pharmaceuticals than radical species and oxidants generated by other AOPs. Tryptophan-like substances and humic-like fluorescing compounds were the most degraded components by all AOPs, which were better removed than microbial products and fulvic-like fluorescing substances. Removal of UV absorbance at 254 (UV254) nm was always low. Overall, chlorine-based AOPs were more effective to reduce fluorescence intensities than similar H2O2-based AOPs. The Cl2/O3/UV process was the most effective AOP to degrade all target micro-pollutants except primidone. On the other hand, the oxidation performance of pharmaceuticals by other ozone-based AOPs followed the order H2O2/O3/UV > O3/UV > O3. UV/Cl2 process outcompeted UV/H2O2 only for the removal of trimethoprim and sulfamethoxazole. Correlations between the removal of pharmaceuticals and spectroscopic indexes (PARAFAC components and UV254) had unique regression parameters for each compound, surrogate parameter and oxidation process. Particularly, a diverse PARAFAC component for each investigated AOP resulted to be the most sensitive surrogate parameter able to monitor small changes of pharmaceuticals removal.

Poly- and perfluoroalkyl substances (PFAS) are a wide group of environmentally persistent organic compounds of industrial origin, which are of great concern due to their harmful impact on human health and ecosystems. Amongst long-chain PFAS, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are the most detected in the aquatic environment, even though their use has been limited by recent regulations. Recently, more attention has been posed on the short-chain compounds, due to their use as an alternative to long-chain ones, and to their high mobility in the water bodies. Therefore, short-chain PFAS have been increasingly detected in the environmental compartments. The main process investigated and implemented for PFAS removal is adsorption. However, to date, most adsorption studies have focused on synthetic water. The main objective of this article is to provide a critical review of the recent peer-reviewed studies on the removal of long- and short-chain PFAS by adsorption. Specific objectives are to review 1) the performance of different adsorbents for both long- and short-chain PFAS, 2) the effect of organic matter, and 3) the adsorbent regeneration techniques. Strong anion-exchange resins seem to better remove both long- and short-chain PFAS. However, the adsorption capacity of short-chain PFAS is lower than that observed for long-chain PFAS. Therefore, short-chain PFAS removal is more challenging. Furthermore, the effect of organic matter on PFAS adsorption in water or wastewater under real environmental conditions is overlooked. In most studies high PFAS levels have been often investigated without organic matter presence. The rapid breakthrough of PFAS is also a limiting factor and the regeneration of PFAS exhausted adsorbents is very challenging and needs more research.

The present study tests the potentiality of a novel microwave based regenerating permeable reactive barrier (MW-PRB) system as combined treatment for Cs-contaminated groundwater. Granular activated carbon (GAC) was selected as adsorptive materials in batch and column MW-regeneration experiments. Experimental and modeling data were elaborated for technical and economic considerations in order to assess the MW-PRB feasibility jointly with essential information regarding its real field applicability. Batch experiments investigated the effects of 10 adsorption-MW regeneration cycles under different MW irradiation conditions (applied electric field = 200–460 V m−1; irradiation times = 1–15 min) by assessing GAC variation properties in term of regeneration yield (δ), specific area and weight loss (WL) variation. Column tests were carried using a dedicated setup essentially including a column filled with GAC implanted in a MW oven cavity (MW electric field of 385 V m−1, irradiation times 5–15 min). Lab-scale results shown the ability of MW in Cs removal from GAC as demonstrated by regeneration yield (δ = 79–110%) and WL (6.78% for 10 cycles) values. This was confirmed in dynamic conditions by data from MW-column tests highlighting the highest Cs removal of ~80% when the maximum regeneration time was applied. Residual Cs concentration in breakthrough curves fitted well with the proposed Yoon and Nelson model (R2 = ~0.97). Results from techno-economic analysis revealed the MW-PRB viability and its advantages also in comparison with conventional PRB systems, demonstrating the concept of combined MW-PRB treatment. Saved cost obtained demonstrated in fact the potential cost effectiveness of MW-PRB system and, consequently, the implementation of novel approach is encouraged. Calculated PRB longevity vs groundwater velocity curves are useful in order to predict long-term PRB performance and the response of the remediation activities, as well as for guiding the design and the scaling-up of MW-PRB treatment.

MBR CAPEX is higher than CAS+coagulation CAPEX; MBR OPEX is lower than CAS CAPEX; MBR may be economically competitive with CAS+coagulation systems.

In this study, it was assessed the effectiveness to correct for inner filter effect (IFE) the fluorescence spectra of several wastewaters (i.e., primary, secondary and tertiary wastewater effluents) and wastewater-impacted surface waters using a common method based on UV absorbance measurements. In samples of secondary/tertiary wastewater effluents and surface waters, IFE was severe at excitation wavelengths240 nm, and it was low (4-11%) at excitation wavelengths340 nm. On the contrary, IFE has always been significant in primary wastewater effluents. After IFE correction, linear relationship was observed between fluorescence and absorbance in dilution series across the full excitation-emission matrix (EEM), although some distortions were still present. Particularly, experimental data showed the presence of static/dynamic quenching of fluorescence due to nitrite/nitrate, which cannot be corrected by IFE correction methods. Indeed, after addition of different nitrate/nitrite concentrations in wastewater (3-40 mg/L as N), the estimated static/dynamic quenching error (QE) after IFE correction was often20% for tyrosine and tryptophan-like fluorescence measured at excitation240 nm. However, the QE was low (5-10%) for fluorescence measured at excitation240 nm. Overall, the QE increased with the increase of nitrite/nitrate concentration in wastewater. Total suspended solids (TSS) (i.e., particulate organic matter) in water produced intense fluorescence peaks in the tyrosine-like and tryptophan-like region of EEM, and TSS increased the absorbance values at all the excitation wavelengths of the UV-visible absorption spectra in unfiltered samples compared to 0.7 μm filtered samples. On the contrary, tertiary effluents employing full scale sand filtration (TSS 2-4 mg/l) had similar UV absorbance and fluorescence spectra to 0.7 μm filtered samples. Finally, it was observed that uncorrected fluorescence intensities in the humic-like region of EEM were similar in both filtered and unfiltered samples, and it was independent of TSS concentration, dilution factor and water quality.

This study is aimed at investigating the levels of polyaromatic hydrocarbons and nitro-polyaromatic hydrocarbons in polluted urban soils and the potential application of microwave heating as decontamination treatment. The soil samples were collected from an area of 0.05 km2 of Catania (Sicily, southern Italy) rural site. HPLC in fluorescence and electrochemical–fluorescence detection mode were used for selective separation, identification and quantification of pollutants in soil samples. A bench-scale microwave treatment was performed irradiating a contaminated soil using different operating powers for removing both kinds of contaminants. Results reveal that soil pollutant concentrations were sometimes higher than those found in other locations. Polyaromatic and nitro-polyaromatic hydrocarbon levels observed suggest a strong contribution from incomplete combustion of gasoline or other fuels also due to the vicinity to the airport. Many polyaromatic hydrocarbon derivatives are more carcinogenic than the initial contaminant form and may have toxicological significance, even if present at much lower concentrations than their parent compounds. Thus, the environmental levels of these pollutants need to be monitored and removed. Contaminant removals from simulated microwave remediation show that the treatment is effective. Results also showed that contaminant features, especially polarity, significantly influence the dielectric properties of the soil and thus the final temperature reachable during the heating processes and the contaminant removals.

This study investigated, using rapid small-scale column testing, the breakthrough of dissolved organic matter (DOM) and eleven emerging organic contaminants (EOCs) during granular activated carbon (GAC) filtration of different water qualities, including wastewater, surface water and synthetic water (riverine organic matter dissolved in deionized water). Fluorescing organic matter was better adsorbed than UV absorbance at 254 nm (UV254) and dissolved organic carbon (DOC) in all tested water. Furthermore, highest adsorption of DOM (in terms of DOC, UV254 and fluorescence) was observed during wastewater filtration. UV absorbing DOM had fast and similar breakthrough in surface water and synthetic water, whereas fluorescence breakthrough was very rapid only in synthetic water. PARAFAC modeling showed that different fluorescing components were differently adsorbed during GAC process. Particularly, fluorescing components with maxima intensity at higher excitation wavelengths, which are corresponding to humic-like fluorescence substances, were better removed than other components in all waters. As opposed to DOM, EOCs were better adsorbed during synthetic water filtration, whereas the fastest EOCs breakthrough was observed during filtration of wastewater, which was the water that determined the highest carbon fouling. Exception was represented by long-chained perfluoroalkylated substances (i.e., PFOA, PFDA and PFOS). Indeed, adsorption of these compounds resulted independent of water quality. In this study was also investigated the applicability of UV254 and fluorescing PARAFAC components to act as surrogates in predicting EOCs removal by GAC in different water matrices. Empirical linear correlation for the investigated EOCs were determined with UV254 and fluorescing components in all water qualities. However, fluorescence measurements resulted more sensitive than UV254 to predict EOC breakthrough during GAC adsorption. When the data from all water qualities was combined, good correlations between the microbial humic-like PARAFAC component and EOC removals were still observed and they resulted independent of water quality if considering only real water matrices (wastewater and surface water). On the contrary, correlations between EOC removals and UV254 removals were independent of water quality when combining data of surface waters and synthetic water, but a different correlation model was needed to predict EOCs breakthrough in wastewater. Accepted version

This work focuses on the stabilisation/solidification (S/S) of radionuclide-polluted soils at different 232Th levels using Portland cement alone and with barite aggregates. The potential of S/S was assessed applying a full testing protocol and calculating γ-radiation shielding (γRS) index, that included the measurement of soil radioactivity before and after the S/S as a function of the emission energy and soil contamination level. The results indicate that setting processes are strongly dependent on the contaminant concentration, and for contamination level higher than 5%, setting time values longer than 72 h. The addition of barite aggregates to the cement gout leads to a slight improvement of the S/S performance in terms of durability and contaminant leaching but reduces the mechanical resistance of the treated soils samples. Barite addition also causes an increase in the γ-rays shielding properties of the S/S treatment up to about 20%. Gamma-ray measurements show that γRS strongly depends on the energy, and that the radioactivity with the contamination level was governed by a linear trend, while, γRS index does not depend on the radionuclide concentration. Results allow the calculated γRS values and those available from other experiments to be applied to hazard radioactive soil contaminations.

2.45 GHz frequency heating treatment of diesel-contaminated soils was applied to investigate the effects of operating power and soil texture on soil temperature profiles and contaminant removal kinetics. Four soil size aggregate fractions, corresponding to medium (200–350 μm) and fine (75–200 μm) sand, silt (10–75 μm) and clay ( lab-scale apparatus for different lengths of time. Results suggest that soil texture significantly influences the contaminant removal kinetics and that thermodynamic and dielectric properties of soils have a major effect on the final temperature reachable during the heating processes. Minimal contaminant residual concentrations ( − 1 ) were achievable only for sandy soils, for which the highest contaminant removals (> 90%) were reached. The power low kinetic model showed a quite good correlation (r 2 > 0.976) with the experimental data for residual concentration at all operating powers and for all soils investigated. Contaminant rate decay ( k ) variation observed for the different soils indicates that contaminant removal processes strictly depend both on thermal properties and specific surface area of soil regulating the adsorption–desorption phenomena related to the decontamination treatment. Especially for sandy soils, microwave heat treatment could be a better choice for remediation of diesel polluted soils compared to several other biological, chemical–physical or conventional thermal treatments due to its removal efficiency.

This review summarizes major findings over the last decade related to N-Nitrosodimethylamine (NDMA) in water and wastewater. In particular, the review is focused on the removal of NDMA and of its precursors by conventional and advanced water and wastewater treatment processes. New information regarding formation mechanisms and precursors are discussed as well. NDMA precursors are generally of anthropogenic origin and their main source in water have been recognized to be wastewater discharges. Chloramination is the most common process that results in formation of NDMA during water and wastewater treatment. However, ozonation of wastewater or highly contaminated surface water can also generate significant levels of NDMA. Thus, NDMA formation control and remediation has become of increasing interest, particularly during treatment of wastewater-impacted water and during potable reuse application. NDMA formation has also been associated with the use of quaternary amine-based coagulants and anion exchange resins. UV photolysis with UV fluence far higher than typical disinfection doses is generally considered the most efficient technology for NDMA mitigation. However, recent studies on the optimization of biological processes offer a potentially lower-energy solution. Options for NDMA control include attenuation of precursor materials through physical removal, biological treatment, and/or deactivation by application of oxidants. Nevertheless, NDMA precursor identification and removal can be challenging and additional research and optimization is needed. As municipal wastewater becomes increasingly used as a source water for drinking, NDMA formation and mitigation strategies will become increasingly more important. The following review provides a summary of the most recent information available.

This review examines the feasibility and sustainability in wastewater reuse. Prior research has shown the need of changes in water utilization patterns, including the establishment of water reuse, to shift towards an efficient and sustainable water use. Nevertheless, the characteristics of local water markets have often determined the feasibility of water reuse systems, and economics have resulted in the major barriers to an actual development of water reuse. A Holistic Approach that takes into account all the reuse factors (political, decisional, social, economic, technological and environmental factors) is needed for a sustainable water reuse implementation. New policies based on circular-economy concept may lead to a “paradigm shift” that starting from the principle of segregation at source could establish a more sustainable model in wastewater management with an enhanced resource recovery.

Microwave heating (MWH) has been recently proposed as a high-performance technique for the remediation of soils contaminated with organic pollutants. However, despite MWH potential advantages, it is scarcely applied due to the lack of full-scale in situ detailed studies. In this work, the in situ MWH applicability for the remediation of hydrocarbon-polluted soils was assessed by means of a specific energy and economic analysis. Essential technical information has also been purchased. Energy and economic analysis was performed using data obtained from modelling for which a dedicated equation-based process computer code simulating MWH phenomena was adopted. Elaborations involved the assessment of the influence of soil texture and moisture as well as operating conditions (supplied power and time) on electric field penetration into the soils and soil temperature variation as a function of time and radial distance from the irradiation source. Main results reveal that sandy soils are more penetrable by MW irradiation with respect to clayey ones. The soil MW penetrability was also observed to increase with decreasing the soil moisture. This was in turn reflected in the soil temperature profiles. However, the major effect on MWH effectiveness is ascribable by the changing of the operating power. In fact, the use of magnetrons with powers lower than 3 kW does not ensure enough microwave penetration into the soil and, therefore, is not suitable for in situ activities, whereas the application of a power of 6 kW led to a maximum treatable radius of 145 cm. In terms of energy consumption, calculation showed that almost 3 days more are in general required to remediate clayey soils with respect to sandy ones. Consequently, the economic analysis revealed that energy costs for sandy soils are about 3 € t−1 lower than those required for clayey soils. Furthermore, the application of a power of 6 instead of 3 kW results in a higher total energy cost, which, jointly with the higher soil volume treatable, leads to almost equal specific costs. The comparison of calculated costs with those of other available clean-up technologies for hydrocarbon-contaminated soils shows that very short remediation times and energy costs obtained (18–27 € t−1) make in situ MWH a deliverable alternative to conventional thermal desorption or physical-chemical techniques.

Data presented in this data article show artifacts (bias and error) that influence fluorescence measurement of dissolved organic matter (DOM) due to samples handling and storage. Data show interferences in fluorescence measurements related to filtration of water by different filter materials, including 0.7 μm glass microfiber filter, 0.45 μm polyvinylidene fluoride (PVDF) membrane, 0.45 μm cellulose nitrate membrane, and 0.45 μm polyethersulfone (PES) syringe filter. Data show also changes of several fluorescence indexes and UV absorbance measurements of wastewater organic matter respect to time under different storage conditions. Particularly, spectroscopic data were acquired using 0.7 μm filtered and unfiltered wastewater samples stored at different temperatures (i.e, room temperature, 4 °C, −20 °C) over a testing period of 21 days. Finally, data show the effect of chlorine disinfection (doses of 0.5–8 mg/L) in fluorescence measurements accomplished in samples from two secondary wastewater effluents. Data of this article are related to the publication “M. Sgroi, E. Gagliano, F.G.A. Vagliasindi, P. Roccaro, Absorbance and EEM fluorescence of wastewater: effects of filters, storage conditions, and chlorination, Chemosphere, 243, 2020, 125292 [1]”. Raw data are available in a public repository ( https://doi.org/10.17632/pf86xs7ybk.1 ).

The disposal of water produced during the petroleum extraction (Produced Water) is a relevant issue due to the occurrence of contaminants. Adsorption on activated carbon is one of the best available technologies for the removal of synthetic organic chemicals from water. However, the replacement and disposal of exhausted carbon is quite expensive and the spent carbon may have to be handled as hazardous waste. The bioregeneration of spent carbon could be a feasible solution; however, hypersaline wastewaters, like Produced Water, are often recalcitrant to biological process due to the strong inhibition by salts (mainly NaCl), elevated temperature, and presence in solution of biocides. In this study, adsorption kinetics, isotherms, and rapid small-scale column tests have been performed to select the type of granular activated carbon (GAC) with the best adsorption capacity of target monoaromatic compounds (benzene and toluene). Continuous-flow pre-loaded GAC biological regeneration experiments were con...

This study examined effects of coagulation and fractionation of natural organic matter on the distribution of trihalomethanes (THM), haloacetic acids (HAA), and haloacetonitriles (HAN) formed in chlorinated water. The precursors of HAA and THM were determined to be associated primarily with the hydrophobic fraction although the hydrophilic fraction is important as well. On the other hand, the precursors of HAN are overwhelmingly hydrophilic with only a negligible contribution of the hydrophobic and transphilic fractions. Higher percentages of HAN were found in the treated waters compared with raw waters, collected from three different full scale water treatment plants. Very strong correlations were found between THM, HAA, and HAN concentrations. Two main correlations between THM and HAN were observed. One was applicable to all raw waters regardless of their fractionation and provenance, while the other was formed by the treated waters, again regardless of their source and fractionation. This result emphasizes that a significant removal of THM and HAA precursors can be achieved via coagulation but it results in a negligible removal of HAN precursors. As a consequence, some changes in treatment trains or operating conditions may need to be considered to minimize the formation of HAN.

In this work, γ-ray shielding and Cs immobilisation performances of high-density magnetite (MG) and iron powder (IP) in Portland cement (PC) based-S/S treatment were investigated. Experimental results were elaborated using a γ-radiation shielding (γRS) index-based approach for assessing the effectiveness of in situ S/S of 137Cs-contaminated soils. Main results reveal that the replacement of PC by MG or IP (up to 50%) leads to a marked increase (up to about 4-fold) in the γ-ray shielding performance, whereas a further material addition decreases the S/S shielding performance. The highest γRS index of ∼26% (662 keV) was found in the case of IP addition (33.3%). The use of MG-mixes allows reaching slightly slower γRS index jointly with the highest Cs-immobilisation of 97.8%. In this case, calculation shows a maximum 137Cs-contamination level successfully treatable by in situ S/S up to ∼2.9 or ∼14.5 kBq kg−1 for the realistic or low probability scenario, respectively, highlighting the possibility to remediate a very wide range of real contamination. Findings show MG - PC S/S as the best choice and could provide a basis for decision-making of S/S remediation of 137Cs-contaminated sites.

Massive amounts of soil and water have been contaminated with hydrocarbon compounds, including fuel and petrochemical products, because of economic and industrial activities. Several chemical-physical or biologic treatments have been studied to remediate hydrocarbon-polluted soils; however, these alternatives may be ineffective, expensive or too lengthy. Otherwise, ex situ conventional thermal desorption was successfully applied to remove organic contaminants, presenting excellent removal values in a very short time but requiring high energy and costs. Microwaves (MW) are a part of the electromagnetic spectrum occurring in the frequency range of 300 MHz–300 GHz, and recently, their application has been identified as a potential tool for hydrocarbon-polluted soil remediation. Compared to other remediation methods, MW heating has advantages including simplicity, safety, flexibility and cost-effectiveness since it offers the potential to significantly reduce treatment times, risk of contamination and costs due to the direct interaction of microwaves with the soil and its ability to overcome heat and mass transfer limitations. In conventional heating systems, the energy is transferred through conduction, convection and radiation, while in MW heating, energy is supplied directly to soil by molecular interaction with the electromagnetic field generated. Therefore, the components of the soil are heated individually and instantaneously, overcoming limits imposed by material heat transfer properties. Literature studies have shown that MW remediation has the potential to remove polar and semipolar organic pollutants from soil. The key factor of the remediation process is represented by the mechanism due to a partial dissipation of the electromagnetic field energy and its conversion into heat, avoiding the limitations of conductive heating phenomena of conventional thermal desorption treatment. This chapter discusses the theoretical background including MW heating process and the related techno-economic features for ex situ full-scale applications in remediation activities of hydrocarbon contaminants.

This paper examines the application of cement (C)-barite (Ba) based-Stabilisation/Solidification (S/S) for the remediation of 137 Cs-contaminated soils, investigating the influence of soil: grout and C: Ba ratios on the shielding performance of the S/S mix assessed as gamma radiation shielding ( γRS ) index variation. Results from experiments were used to perform a novel approach and an economic analysis in order to calculate the effective dose reduction achievable by S/S and to assess the optimum quantities and costs of selected mixes, respectively. Gamma ray spectrometer measurements indicate that γRS index increases with increasing barite percentage up to a maximum level of 50%; however a further increase results in a worsening of the shielding performances. A maximum γRS variation of 46.5% was recorded with grout percentage increasing from 16.6 to 50%. At the photon energy of 662 keV ( 137 Cs), the maximum grout amount results in the possibility to shield up to 24.1% of γ-rays emitted. The effective dose reduction achievable by the investigated S/S allows a maximum 137 Cs-soil contamination in the range 2.94–14.55 kBq kg −1 successfully treatable employing a soil: grout ratio of 1: 1 (C: Ba = 1:1). Technical data, jointly with economic analysis findings, make cement-barite based-S/S very competitive in cost-effectiveness and could provide a basis for decision-making of 137 Cs-contaminated site remediation.

Constructed wetlands (CWs) are nature-based wastewater treatment systems, which are often implemented in decentralized areas and small communities. In recent decades, the CW technology has rapidly evolved through the use of various designs and operational modes or other intensifications so as to improve effluent water quality with respect to various pollutants from wastewater. In the present study, the removal of conventional water quality parameters, emerging organic contaminants (EOCs) and fluorescence signature was investigated in a hybrid constructed wetland system comprising different CW configurations: (i) unsaturated vertical subsurface flow (VF), (ii) partial saturated vertical subsurface flow (VF sat), (iii) saturated horizontal flow (HF) and (iv) free water surface (FWS) wetlands. The obtained results showed higher removal of BOD5, COD and fluorescing organic matter in the aerobic VF reactor, whereas the anoxic HF wetland was the most efficient unit for nitrogen removal. The partially saturated VF wetland showed a greater performance in the reduction of nitrogen and highly biodegradable EOCs than the unsaturated VF bed. Finally, linear regression analyses performed between removal of water quality parameters, EOCs and fluorescence measurements suggested the possibility to use fluorescence indexes as useful indicators of water treatment efficacy and/or surrogate parameters for EOCs monitoring.

Mercury (Hg) and Hg-PAH removal effectiveness of several electrokinetic (EK) decontamination treatments, including the combined use of eco-friendly enhancing agents, was investigated in this work as a potential remedial treatment of heavily contaminated marine sediments. After a 400-h EK treatment, main results revealed a very poor Hg mobilization without the use of an appropriate conditioning agent, mainly due to the strong Hg-bounds with carbonates, organic matter and sulphides, which were present at high concentrations. The use of EDTA as processing fluid resulted in a slight improvement of Hg removal (∼15%). A further increase in Hg removal rate of ∼39% can be achieved with methylglycinediacetic acid (MGDA) as anodic solution. The best Hg-removal of ∼71% was obtained by means of the simultaneous use of MGDA and Tween® 80 due to their synergistic action in remedial processes. The same type of treatment led to a slightly lower total Hg-removal of ∼67% when a shorter time of 240 h was considered. In the case Hg and PAHs as sediment co-contaminants, results revealed a total PAH-removal of 59.45%. The co-presence of PAHs significantly affected the electric current circulating in the system and the electrosmotic values, leading to a reduction of about 5% in Hg removal respect to the case where PAHs were not present in the sediments. Nevertheless, the combined application of Tween® 80 and MGDA in enhanced-EK treatment allows the possibility to successfully remove both highly persistent Hg and PAHs from marine sediments with high removal percentages. Obtained data can be useful for further enhanced EK treatments of sediments contaminated with Hg and PAHs, as well as providing basic information for future cost analysis.

The radioactive waste produced by mining activities contains a series of long-lived radionuclides, such as uranium (U), radium (Ra), and thorium (Th) isotopes. These radionuclides are considered to be TENORM (Technologically Enhanced Naturally Occurring Radioactive Materials) due to their high concentration in the mining byproducts. Their indiscriminate and improper disposal increases the risk of soil and groundwater contamination. According to the Environmental Protection Agency (EPA), among TENORM, 232 thorium ( 232 Th) is the primary source of contamination at the superfund sites, due to extraction activities. 232 Th, as a soil pollutant, presents both a chemical and radiological hazard, and risks connected to 232 Th exposure are increased by its γ-ray emission capacity. Very limited techniques are present in the literature to remediate 232 Th-contaminated soils, but the cement-based stabilization/solidification (S/S) technique has been shown to be a perfect choice for this purpose. S/S has three main advantages: (i) it is well established as an efficient and cost-effective treatment, (ii) it has high versatility, and (iii) it produces no waste or contaminated wastewater that needs landfill disposal. In addition, employing of high-density binder/materials with γ-radiation shielding properties represents a key factor in remedial activities of radionuclide-polluted soils. In this work, we report the theoretical background including the S/S process and recent related scientific and technoeconomic development for the S/S application in reclamation activities of 232 Th-contaminated soils from mining activities.

After the observation of cases of malignant pleural neoplasm in Biancavilla (Catania, Italy), a new asbestiform fiber, named fluoro-edenite (NaCa2Mg5(Si7Al)O22F2), was found in a stone quarry use for local building industry and in the lung tissue of an 86 years old woman who died from pleural mesothelioma. As a consequence the Italian Ministry of the Environment has included the Biancavilla site in the National Priority List. In this study, a point of view on the results from a large scale environmental monitoring program conducted for the implementation of the site investigation is presented. The obtained dataset from the environmental monitoring program results in more than 3,000 values of concentration of asbestos like fibers and fluoro-edenite fibers in air, water and top soil. These data are spatially and temporally distributed in the Biancavilla site, therefore the development and application of a Geographic Information Systems (GIS) was very useful to review, manage and analyze the obtained data and to give direction to the stakeholders in order to define the required remediation activities. A WebGIS was also developed to provide a rapid GIS access and data management by various control bodies.

Effects of chlorine dose, reaction time and temperature on the formation of disinfection by-products (DBPs) and corresponding changes in the absorbance of natural organic matter (NOM) in chlorinated water were examined in this study. Although variations of chlorination parameters, notably those of temperature that was varied from 3 to 35 degrees C, influenced the kinetics of chlorine consumption and DBP release, correlations between chlorine consumption, concentrations of trihalomethanes (THMs), haloacetonitriles (HANs), other DBP species and, on the other hand, intensity of differential absorbance at 272nm remained unaffected. THM and HAN speciation was correlated with the differential absorbance, indicating preferential incorporation of bromine at the initial phases of halogenation that correspond to low DeltaA(272) values. Because the DeltaA(272) parameter is a strong indicator of the formation of DBP species and chlorine decay, optimization of chlorination operations and DBPs control based on this parameter can be beneficial for many water utilities, especially those with pronounced variability of water temperature and residence times.

The main goal of this study was the application of a bench-scale microwave (MW) heating treatment of soils contaminated with polycyclic aromatic hydrocarbon (PAHs) and nitro-PAHs (N-PAHs), investigating the effects of various operating conditions on contaminant removal kinetics. For simulated MW treatment, a fine sandy soil was artificially contaminated with PAHs or N-PAHs and irradiated for a period of 5–60 min, applying powers in the range of 250–1000 W. Kinetic models were fitted with contaminant residual concentrations in order to calculate the desorption parameters useful for studying the removal process. Results suggest that contaminant properties, especially polarity, significantly influence the maximum temperature reachable during the heating processes and the contaminant removal kinetics. The total PAH removal was achievable only for biphenyl (Bph) or fluorene (Flu), whereas residual concentrations were reduced to less than 2 mg kg −1 for anthracene (Ant) or phenanthrene (Phe). N-PAH concentrations lower than 0.05 ng kg −1 were observed for all the compounds investigated. Overall, different mechanisms, namely, thermal desorption, molecular bond breaking, selective heating and contaminant stripping took place during PAH or N-PAH removal. The kinetic parameters are useful for studying the removal process and for predicting the response of the remediation activities, as well as for guiding the design and the scale-up of microwave treatment systems. PAH/N-PAH removal mechanism results could also provide basic information and be helpful in order to improve the development of novel MW based-remediation technologies for soils contaminated with PAHs and their derivatives.

Aquifer contamination with diesel fuel is a worldwide environmental problem, and related available remediation technologies may not be adequately efficient, especially for the simultaneous treatment of both solid and water phases. In this paper, a lab-scale 2.45 GHz microwave (MW) treatment of an artificially diesel-contaminated aquifer was applied to investigate the effects of operating power (160, 350 and 500 W) and time on temperature profiles and contaminant removal from both solid and water phases. Results suggest that in diesel-contaminated aquifer MW remediation, power significantly influences the final reachable temperature and, consequently, contaminant removal kinetics. A maximum temperature of about 120 °C was reached at 500 W. Observed temperature values depended on the simultaneous irradiation of both aquifer grains and groundwater. In this case, solid phase heating is limited by the maximum temperature that interstitial water can reach before evaporation. A minimal residual diesel concentration of about 100 mg kg(-1) or 100 mg L(-1) was achieved by applying a power of 500 W for a time of 60 min for the solid or water phase, respectively. Measured residual TPH fractions showed that MW heating resulted in preferential effects of the removal of different TPH molecular weight fractions and that the evaporation-stripping phenomena plays a major role in final contaminant removal processes. The power low kinetic equation shows an excellent fit (r(2) > 0.993) with the solid phase residual concentration observed for all the powers investigated. A maximum diesel removal of 88 or 80% was observed for the MW treatment of the solid or water phase, respectively, highlighting the possibility to successfully and simultaneously remediate both the aquifer phases. Consequently, MW, compared to other biological or chemical-physical treatments, appears to be a better choice for the fast remediation of diesel-contaminated aquifers.

Microwave (MW) heating has been identified as a potential cost-effective technique to remediate hydrocarbon-polluted soils; however, the soil texture and properties could have a great impact on its full-scale treatment. In addition, very limited energy and economical data on MW treatment are available, and this lack makes its real application very limited. In this work, a first experimental phase was performed simulating a MW of several hydrocarbon-polluted soils. Obtained data were elaborated for a techno-economic analysis. Four soil textures, corresponding to medium, fine silica sand (at different soil moistures), silt as silica flour and clay as kaolin, were artificially contaminated with diesel fuel and irradiated by MWs using a bench scale apparatus. Soil samples were treated applying four specific power values at different times. At the end, soil temperature was measured, whereas residual contaminant concentrations were measured and fitted considering and exponential decay kinetic model. Temperature data, as well as kinetic parameters obtained, were used for the techno-economic analysis. The changing of the internal electric field was calculated for all the soils and operating conditions, then considering initial contamination values ranging from 750 to 5000 mg kg−1, the minimal remediation time, specific energy and costs for the remediation were assessed. At low powers, MW effectiveness is limited by low soil moistures or fine soil textures due to a limitation of the electric field penetration, whereas when high powers are used soil properties have a limited effect. Remediation time, as a function of the initial contamination level, follows a linear trend, except for dry soils, for which an exponential trend was observed. For powers higher than 30 kW Kg−1, remediation times lower than about 100 min are needed, for all the moisturized soils, in order to treat a contamination of 5000 mg kg−1. The variation of soil moisture or soil texture results in the range 20–160 € ton−1, and doubled costs are required for the treatment of clayey soils respect to sandy soils. The analysis performed suggests that soil layers lower than 70 cm should be considered for ex situ remediation. MW has been shown as a quick technique also for high hydrocarbon concentrations; however, for energy saving, the application of some powers should be avoid. Unmoisturized or fine texture soil treatment results in higher costs; however, a maximum cost of 160 € ton−1 generally makes MW heating a quick and cost-effective ex situ technique.

In the Volcano Etna area (Sicily) a substantial part of groundwater, used for potable purpose, has concentrations of metals (vanadium, iron and manganese) higher than the maximum contaminant levels (MCLs) set by European and National regulations (European Directive 98/83 and D.Lgs. 31/2001). Specifically, high levels of manganese, up to 1810 μg/l, significantly exceeding the maximum contaminant level (MCL = 50 μg/l), were detected in groundwaters currently used as drinking water supply upwelled from the Etna Volcano aquifer. The paper presents the results of the manganese removal process by potassium permanganate oxidation followed by flocculation, settling and filtration. Batch tests were carried out varying pH, oxidant doses and polyelectrolytes. Two different filters (35 μm and 0.45 μm mesh) were tested as a final step of the treatment. Significant removal (up to 95%) was achieved by addition of polyelectrolytes at pH 8.5, with a 0.5 stoichiometric dose of oxidant and final filtration through 35 μm mesh filter.