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A wide use of foaming agents as lubricants is required in mechanized tunneling. Their main component, the anionic surfactant sodium lauryl ether sulphate (SLES), can remain in residual concentrations in soil debris, influencing their potential reuse as by-product. This study aimed at evaluating the environmental fate and effects of a foaming product used for conditioning soils collected from real excavation sites, in the presence/absence of an anti-clogging polymer, both containing SLES. Soil microcosm experiments were set-up and incubated for 28 days. Over time, soils and their water extracts (elutriates) were collected to perform both ecotoxicological tests (Vibrio fischeri, Lepidium sativum, Eisenia foetida, Hetereocypris incongruens, Danio rerio) and SLES analysis. The results showed that, just after conditioning, SLES did not exert any hazardous effect on the organisms tested except for the bacterium V. fischeri, which was the most sensitive to its presence. However, from day seven the toxic effect on the bacterium was never observed thanks to the SLES decrease in the elutriates (&lt, 2 mg/L). SLES degraded in soils (half-lives from 9 to 25 days) with higher disappearance rates corresponding to higher values of microbial abundances. This study highlights the importance of site-specific studies for assessing the environmental reuse of spoil materials.

Plant-assisted bioremediaton (PABR) is an effective green technology for removing contaminants from soils. It relies on the sinergistic interactions between roots and microrganisms of the rhizosphere for removing, transforming and contain toxic compounds. Poplars were proved to be very efficient in promoting degradation of chloride organic pollutants such as lindane and polychlorobyphenils (PCBs) in both laboratory and field scale experiments. Due to their high molecular stability, low solubility in water and high tendency to adsorb on particulate phase, PCBs are extremely hard to remove from soil. In this work, some crucial aspects of the PABR strategy in recovering two historically contaminated areas, located in Southern Italy, characterized by different PCB amounts (medium and high concentrations, respectively), are illustrated.Two poplar treated areas, inside the survey site, were set up at a distance of two years from each other (2013 and 2015, respectively). In the first one, characterized by a medium PCB contamination level (PCB ~250 ng/g) about 600 poplar cuttings were planted; instead, in the second one, affected by high PCB contamination (PCB >2000 ng/g), about 750 poplar cuttings were planted.Chemical investigations of soil properties and pollutants (PCB congeners) were carried out before plantation and at different times after poplar planting, in both the PABR treated areas. Moreover, microbial analyses such as the total microbial abundance (DAPI counts), cell viability (live/dead method), microbial activity (dehydrogenase activity) and the sequencing of 16S DNA (Miseq-Illumina) were performed for evaluating microbial community structure and functioning in the poplar rhizosphere. Moreover, in March 2019, a compost (CMP) or biochar (BC) treatment was also performed on some contaminated plots inside the highest polluted poplar treated area in order to increase soil quality and promote PCB degradation.The results obtained in the first poplar treated area, affected by medium PCB contamination, showed the effectiveness of PABR in restoring this area, promoting active bacteria able to degrade and contain pollutants and increase soil quality. In the second poplar treated area, the high PCB levels and the soil nutrient impoverishment favouring stress conditions for poplars limiting their growth. The addition of the fertilizers (compost or biochar) promoted an increase in soil quality and microbial activity promoting the bioremediation processes.

The availability of reliable and long time series of runoff data is fundamental for most of the hydrological analyses and for the assessment and the management of water resources even in condition of global climatic change. However, hydrologic data sets are often characterized by a short duration and also suffer from missing data values, mainly due to malfunctioning of gauging stations for a specific period. In order to overcome this problem and obtain long and continuous runoff time series, different models and methods have been previously developed and proposed. While some models, used to extent the streamflow record, are conceptual, empirical, regressive models based on the rainfall input, other models are based on the derivation of runoff maps at different time scale; these maps allow the runoff estimation in gauged basins characterized by the absence of data or in ungauged basins. Aim of this paper is the derivation of a map relative to the mean annual runoff at regional scale using a stochastic approach derived from the kriging interpolator. This approach can be assimilated to a kriging system, which considers explicitly the areal nature of runoff variable by imposing the constraint of the water balance; it allows to derive gridded annual runoff maps with finer and finer resolution. The methodology has been applied to 23 main hydrographic basins of Sicily, Italy using the mean annual runoff dataset provided by Osservatorio delle Acque. All these basins have been previously grouped in three homogeneous zones, as suggested by previous studies. A cross-validation procedure has been performed in order to validate the procedure for each homogeneous zone.