Contaminants of emerging concern (CECs) are not commonly monitored in the environment, but they can enter the environment from a variety of sources. The most worrying consequence of their wide use and environmental diffusion is the increase in the possible exposure pathways for humans. Moreover, knowledge of their behavior in the environment, toxicity, and biological effects is limited or not available for most CECs. The aim of this work is to edit the state of the art on few selected CECs having the potential to enter the soil and aquatic systems and cause adverse effects in humans, wildlife, and the environment: bisphenol A (BPA), nonylphenol (NP), benzophenones (BPs), and benzotriazole (BT). Some reviews are already available on BPA and NP, reporting about their behavior in surface water and sediments, but scarce and scattered information is available about their presence in soil and groundwater. Only a few studies are available about BPs and BT in the environment, in particular in soil and groundwater. This work summarizes the information available in the literature about the incidence and behavior of these compounds in the different environmental matrices and food. In particular, the review focuses on the physical-chemical properties, the environmental fate, the major degradation byproducts, and the environmental evidence of the selected CECs.

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Biobarriers (BBs) are a new type of in situ technology for the remediation of contaminated groundwater. In recent years, this remediation technique has been more and more used in place of traditional Pump & Treat systems or other in situ technologies both in the USA and Europe. This work reviews the main experiences of BBs. The literature contains reports about tests and application at different scales (laboratory, pilot and full scale), which have been analyzed according to the aim of the study, the operative conditions adopted, the filling material, the inoculation procedure, the electron acceptor and the nutrient delivery systems. Operative conditions were extremely varied. Lab scale experiments pointed out good results in terms of pollutant removal efficiency. Pilot scale tests and full-scale applications confirmed the results obtained at lab scale, but also pointed out the importance of design for a proficient remediation system. The experiences underlined some possible critical issues: (a) the filling material must ensure proper hydraulic properties, but it also must be capable of keeping biomass in the reactive zone; (b) inoculation is a critical step and measurements should be carried out to check the initial distribution of microorganisms and its evolution over time; (c) electron acceptor and nutrient supply is usually required, but oxygenation into anaerobic aquifers can be critical.

Purpose Millions of cubic meters of sediments are dredged every year in the world. About 10–20%onweight basis of this material is contaminated by organic and/or inorganic pollutants. This work presents the laboratory tests performed to study a system for the remediation and reuse of mercurycontaminated sediments. The treatment is based on a cementbased granulation step (solidification/stabilization (S/S)), followed by a thermal process under vacuum during which volatile and semi-volatile compounds are removed. The experiments focused on: (1) cement hydration reactions; (2) pollutant removal efficiencies; and (3) leaching behavior, in relation to temperature and duration of the thermal process. Mercury speciation was also investigated.\ud Materials and methods Dredged at the marine harbor of Augusta (SR, Italy), the sediments used in the experiments were highly polluted by mercury (200 mgkg−1dry weight (d.w.)). The recipe applied in the S/S step was based on the particle size distribution of the resulting granulates. An indirectly–heated batch system operated under vacuum (2.6±1.3 103 Pa) at: (1) 150°C for 16 h; (2) 200°C for 6 h; (3) 250°C for 4 h; or (4) 280°C for 4 h. X-ray diffraction spectroscopy and scanning electron microscopy were used to study cement hydration reactions. Total mercury concentration and leaching tests were carried out to assess the effects of the different treatment conditions.\ud Results and discussion The best results were obtained by treating the granulate at 250°C for 4 h. Under these conditions, mercury final concentration was 49 mgkg−1 d.w., resulting in a removal efficiency of 63% referred to the granular material before thermal treatment, and 75% referred to the sediment. The concentrations measured in the leachate were compatible with the Italian requirements for reuse, with some exceptions (pH, chlorides, nickel, copper, and COD) ascribed to the specific nature of the sediment. Mercury speciation analyses pointed out changes after both the treatment steps.\ud Conclusions The final granulates accomplish most Italian requirements for reuse, even though an improvement in the S/S step or an additional washing step would help for the exceptions mentioned above. Different reuse options in civil engineering (e.g., filling material, road material, concrete aggregates, etc.) will be evaluated also taking into consideration the mechanical properties. Further studies will be carried out to assess the long-term leaching behavior and leaching under different pH conditions

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