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A method to evaluate the ecological risk of chemical mixtures in water bodies is here presented. In the first phase, the approach considered routine chemical monitoring data (MEC: measured environmental concentrations) obtained from the Italian National Institute for Environmental Protection and Research, which were georeferenced to a single coordinate system for each monitoring station. The overall mixture toxicity were then evaluated for three representative aquatic organisms (algae, Daphnia, fish) using the concentration addition model to combine exposure with ecotoxicological data (from different databases). A database management system was used to facilitate the creation, organisation, and management of the large datasets of this study. The outputs were obtained as GIS-based mixture risk maps and tables (listing the toxic unit of mixtures and individual substances) useful for further analysis. The method was applied to an Italian watershed (Adda River) as a case study. In the first phase, the mixture toxicity was calculated using two scenarios: best- and worst-case; wherein the former included only those compounds that were be detected, while the latter involved also substances with concentrations below the limit of quantification. The ratio between the two scenarios indicated the range within which mixture toxicity should ideally vary. The method demonstrates that these ratios were very small when the calculated toxicity using the best case indicated a potential risk and vice versa, indicating that the worst-case scenario could not be appropriate (extremely conservative). Consequently, in the successive phase, we focused exclusively on the best-case scenario. Finally, this approach allowed the priority mixture identification (those most likely occurring in the analysed water samples), algae as the organism at the highest risk, and the substances that contributed the most to the overall mixture toxicity (terbuthylazine and s-metolachlor for algae, and chlorpyrifos and chlorpyrifos-CH3 for Daphnia and fish).

Bioremediation technologies are useful and sustainable solutions for recovering pollutants from ecosystems. In particular, the plant-assisted bioremediation or phyto-assisted bioremediation (PABR) strategy, relying on the synergistic actions between plant root system and natural microorganisms (bacteria and fungi), can be effective for stabilizing, storing, and degrading contaminants of polluted soils. Plant species through release of root exudates can stimulate biodegradation activity of natural soil microorganisms in the rhizosphere. The use of organic amendments (e.g., biochar, compost) in PABR applications can also be useful for enhancing plant growth, soil quality and increase the biodegradation of some contaminants. Moreover, PABR technology produces biomass, a by-product, which can be profitably valorised for producing energy in line with a circular economy. Deeper investigations on the overall processes in order to improve PABR effectiveness and ensure its zero impact on environment are desirable.

Fagus sylvatica L. is widely distributed across Europe thanks to its high adaptability in a wide variety of soils and climate. Microbial communities are essential for maintaining forest soil quality and are responsible for forest ecosystem functioning; the ability of soil microorganisms to respond to abiotic stressors (e.g., organic carbon losses, water scarcity, temperature changes) is crucial under ongoing environmental changes and also supports tree health. In this study, soil samples were collected from pure beech plots as part of the COST Action project CLIMO to find differences in microbial community characteristics and evaluate the effects of soil properties on microbial communities across gradients of elevation, latitude, and longitude. Positive relationships were found between organic carbon content and both microbial abundance and dehydrogenase activity. Dehydrogenase and catalase activities were elevation-correlated and microbial activities were longitude-correlated. In the most southern beech plot, the microbial community was abundant and displayed high activities. This shows that microbial communities could help tree populations to better adapt to predicted changes in environmental conditions in the future. We suggest that research into forest health and beech performance should also test soil microbial enzymatic activity, particularly under changing climate conditions, to assist in identifying adaptation strategies.

The anionic surfactant sodium lauryl ether sulfate (SLES) is the main component of most commercial foaming agents (FAs) used in the excavation of highway and railway tunnels with Earth pressure balance-tunnel boring machines (EPB-TBMs). Several hundreds of millions of tons of spoil material, consisting of soil mixed with FAs, are produced worldwide, raising the issue of their handling and safe disposal. Reducing waste production and reusing by-products are the primary objectives of the “circular economy,” and in this context, the biodegradation of SLES becomes a key question in reclaiming excavated soils, especially at construction sites where SLES degradation on the spot is not possible because of lack of space for temporary spoil material storage. The aim of the present work was to apply a bacterial consortium (BC) of SLES degraders to spoil material excavated with an EPB-TBM and coming from a real construction site. For this purpose, the BC capability to accelerate SLES degradation was tested. Preliminary BC growth, degradation tests, and ecotoxicological evaluations were performed on a selected FA. Subsequently, a bioaugmentation experiment was conducted; and the microbial abundance, viability, and SLES concentrations in spoil material were evaluated over the experimental time (0.5, 3, 6, 24, 48, and 144 h). Moreover, the corresponding aqueous elutriates were extracted from all the soil samples and analyzed for SLES concentration and ecotoxicological evaluations with the bacterium Aliivibrio fischeri. The preliminary experiments showed the BC capability to grow under 14 different concentrations of the FA. The maximum BC growth rates and degradation efficiency (100%) were achieved with initial SLES concentrations of 125, 250, and 500 mg/L. The subsequent bioaugmentation of the spoil material with BC significantly (sixfold) improved the degradation time of SLES (DT50 1 day) compared with natural attenuation (DT50 6 days). In line with this result, neither SLES residues nor toxicity was recorded in the soil extracts showing the spoil material as a by-product promptly usable. The bioaugmentation with BC can be a very useful for cleaning spoil material produced in underground construction where its temporary storage (for SLES natural biodegradation) is not possible.

River pollution from different sources can affect ecosystems in different ways with consequences on water quality for both biota and human health. The River Danube was selected to perform chemical and biological analyses. The river was sampled at three different points, one inside Budapest and two just outside. Water samples were collected twice in the same year (April and November 2017) in order to determine metal concentrations, occurrence of ubiquitous contaminants such as Polycyclic Aromatic Hydrocarbons (PAHs) and some not-yet-regulated pharmaceuticals (17β-estradiol, 17α-ethinylestradiol, estrone, fenoprofen, naproxen, ibuprofen, gemfibrozil, sulfamethoxazole and ciprofloxacin). Moreover, the structure of the natural microbial community was also analysed in terms of total microbial abundance and identification of the main bacterial groups by the Fluorescence In Situ method. Finally, the same water samples were tested to assess their possible estrogenic effects using the yeast estrogenic screen (YES). The results show diffuse residual concentrations of both PAHs and pharmaceuticals in the river stretch investigated, with the highest values in April (in line with a lower rainfall input) and at the sampling site inside the city of Budapest. At this latter point, the natural microbial community was less abundant than in the other sites, suggesting detrimental effects of the overall contaminants on its structure. Finally, an estrogenic activity was found in all water samples analysed with higher average values in line with higher amounts of contaminants in the April sampling.

A Monviso clone has been applied to promote PCB degradation in a soil historically contaminated by polychlorinated biphenyls (PCBs) and heavy metals (HMs). The multi-contaminated area is located in Southern Italy. PCBs, HMs, and the soil microbial community (abundance, viability, and structure) were analysed in selected plots of the poplar-treated area. At 900 days after poplar planting, chemical analyses showed that PCBs and most of HMs diminished under the Italian legal limits. The overall results suggest that the poplar clone was effective in promoting PCB rhizodegradation and HM phytostabilization. Organic carbon content increased strongly in the rhizosphere of the planted plots. Microbiological results highlighted an overall increase in microbial abundance, cell viability, and the presence of bacterial groups involved in PCB degradation. The poplar-based bioremediation technology is a nature-based solution able to promote the recovery of soil quality in terms of contaminant removal, increase in organic carbon, and stimulation of autochthonous bacterial groups able to transform PCBs.

Sodium lauryl ether sulphate (SLES) is the anionic surfactant commonly utilized as the main synthetic chemical component in most foaming agents used in mechanized tunnelling. This produces huge amounts of soil debris which can contain residual concentrations of SLES. The absence of environmental quality standards for soil and water and the limited information about SLES persistence in real excavated soils do not facilitate any re-use of soil debris as by-products. The environmental risk assessment (ERA) of foaming agents containing SLES can be a valid tool for this purpose. In this study, an ERA analysis of SLES in 12 commercial formulations (cf) used for tunnelling excavation was performed. Various soils from different tunnel excavation sites were conditioned with the selected foaming agents containing SLES. Predicted or measured environmental concentrations (PECs, MECs) were determined and then compared with the Predicted No Effect Concentrations (PNECs) for both the terrestrial and aquatic compartments. The results indicate a reduction of the potential risk over time for these ecosystems, with differences depending on both the commercial foaming formulation and the spoil material characteristics. However, because potential threats to the natural environment cannot be excluded, some risk management and mitigation actions are discussed.

Reliable stable indicators are very important for assessing soil quality. This paper compares the dynamics of microbial parameters in two different soils (rich/poor in organic carbon), contaminated in laboratory experiments with an equal dose of heavy metals (HMs) after 30 and 90 days. For this purpose, the changes in the number, biomass, and taxonomic structure of bacterial and fungal communities were assessed in microcosm experiments using an organic carbon–rich ordinary chernozem (Ch-humus-rich soil) and a depleted carbon agrozem (Ag-humus-poor soil), spiked with high concentrations of a zinc, lead, and copper solution (1100 Zn + 660 Cu + 650 Pb mg per kg soil). At the 30th and 90th day from HM contamination, soil samples were collected for analyzing microbial community lipid markers by gas chromatography-mass spectrometry. The results show how both biomass and taxonomic structure of the bacterial and fungal communities analyzed were differently sensitive to HM contamination, depending on the type of soil. The Ag-humus-poor soil microbial community was significantly affected by the HM pollution with an increase in both fungi and bacteria and inside the latter several species changed their percentages. Differently, the Ch-humus-rich soil microbial community was not influenced by the HM addition. However, the negative impact of HM can manifest itself over time, so the microbial structure and its functioning cannot represent accurate indicators of the quality of all soil types. The results show that microbial characteristics should be taken into account only in a comprehensive assessment of soil quality in accordance with ISO 19,204:2017—soil quality TRIAD approach. This approach to environmental risk assessment combines biological data (from bioassay and ecological observations) with chemical analysis.

Background: Due to their widespread use in industrial applications in recent decades, Polychlorobiphenyls (PCBs) and heavy metals (HMs) are the most common soil contaminants worldwide, posing a risk for both ecosystems and human health.Results: a poplar-assisted bioremediation strategy has been applied for more than four years to a historically contaminated area (PCBs and HMs) in Southern Italy using the Monviso poplar clone. This clone was effective in promoting a decrease in all contaminants and an increase in soil quality in terms of organic carbon and microbial abundance. Moreover, a significant shift in the structure and functioning of the belowground microbial community was also observed when analysing both DNA and cDNA sequencing. In fact, an increase in bacterial genera belonging to Proteobacteria and able to degrade PCBs and resist HMs was observed. Moreover, the functional profiling of the microbial community predicted by PICRUSt2 made it possible to identify several genes associated with PCB transformation (e.g. bphAa, bphAb, bphB, bphC), response to HM oxidative stress (e.g. catalase, superoxide reductase, peroxidase) and HM uptake and expulsion (e.g. ABC transporters).Conclusions: This work demonstrated the effectiveness of the poplar clone used in stimulating the natural belowground microbial community to remove contaminants (phyto-assisted bioremediation) and improve the overall soil quality. It is a practical example of a nature based solution involving synergic interactions between plants and the belowground microbial community.

Mechanized excavation of tunnels with Earth Pressure Balance-Tunnel Boring Machines requires the use of foaming agents. The latter contain the anionic surfactant sodium lauryl ether sulphate (SLES) as the main compound. The re-use as a by-product of excavated soil containing foaming agents (spoil material) can pose a risk for soil and particularly for aquatic ecosystems if they are close to the spoil material final destination site. This work reports the chemical results (SLES residual concentrations) and ecotoxicological effects (battery of five tests) of 28 day-mesocosm studies performed at a tunnelling construction site. The soil mesocosms were set up with two different lithologies, which contained four different foaming agent products at the highest amounts used for excavation. The decrease in SLES concentrations and the ecotoxicological tests were performed in soil and its water extract (elutriate) at different times (0, 7, 14, 28 d). Elutriates were prepared in order to simulate a possible SLES leaching from soil to water. The results showed a decrease in SLES over time and different ecotoxicological responses depending not only on the initial amount of each product, but also on the soil lithology and organism tested (aquatic or terrestrial). This study showed how only site-specific ecotoxicological evaluations can ensure a safe management of the spoil material, making possible the re-use of soil and avoiding production of waste.

Huge amounts of soil debris are produced during the underground excavation with Earth Pressure Balance-Tunnel Boring Machines (EPB-TBM). Soil debris may contain residual concentrations of the anionic surfactant sodium lauryl ether sulphate (SLES), the main component in some foaming agents used as excavation additives. The reuse of this debris or its discharge as waste is a critical environmental question in construction engineering. There are only few studies on ecotoxicological effects on soil debris coming from a real excavation site. The aim of this study was to evaluate the ecotoxicity of two deep soils, with different lithological compositions, conditioned with three foaming agents. In some cases, lime was added to the soil. The soils were placed in mesocosms (1 m3) to simulate the temporary storage of the soil debris at a construction site. At fixed times, soil sub-samples were collected and ecotoxicological tests on terrestrial organisms (Lepidium sativum, Eisenia foetida) and an assessment of SLES concentration were performed with soils and aqueous elutriates produced from them. Results showed that at day 28, a SLES reduction was observed in both the soil and aqueous elutriates, with various rates of decrease. The differences were due to different soil lithological compositions and foaming agent products composition. In general, the two soils were not suitable for both plant growth and earthworm reproduction, but in Soil 1 the earthworm mortality was very low, except when lime was added. Tests with soil elutriates showed that 7 days after conditioning no toxic effect was found for the organisms tested.

Alkylethoxysulfate (AES) surfactants are the main component of most commercial products used for soil conditioning in the excavation industry, in particular as lubricants for mechanized tunnelling. Huge amounts of soil debris are produced during the excavation process and their possible re-use as by-products (e.g. land covering) or discharge as waste is a critical question in civil engineering. There can be an environmental impact from the potential ecotoxicity of the residual chemical mixture occurring in the foam-conditioned excavated soil. Chemical analyses are not able on their own to assess the potential hazards for the ecosystem ascribable to inadequate management of this kind of conditioned soil. Ecotoxicological tests, on the other hand, provide useful overall information about the potential effects of conditioned debris on soil and aquatic biota, including synergic ones, whether or not there is a detailed knowledge of the chemical composition of all the components of the commercial foaming products. In this context, the objective of this work was to evaluate the overall ecotoxicity of excavated soil conditioned with two common foaming products containing sodium lauryl ether sulphate (SLES) as the main component, in order to verify their possible re-use as by-products. For this purpose, two soils with different geopedological characteristics were conditioned with the commercial foaming agents at the concentrations utilised for mechanized tunnelling and then used for microcosm laboratory experiments. Soil sub-samples were collected at different times (0, 7, 14, 28 days) of incubation and soil elutriates were produced to assess the effects of the foaming agents on five test species (Pseudokirchneriella subcapitata, Daphnia magna, Danio rerio, Vibrio fischeri and Lepidium sativum). The results of the tests were then compared with SLES residual concentrations in the elutriates, determined with the MBAS (methylene blue active substances) spectrophotometric method. Finally, the data were combined in a battery index, which proved effective at evaluating the overall ecotoxicity in a real-life situation of two different excavated soils conditioned with the two products analysed.

Among the different pharmaceuticals present in soil and water ecosystems as micro-contaminants, considerable attention has been paid to antibiotics, since their increasing use and the consequent development of multi-resistant bacteria pose serious risks to human and veterinary health. Moreover, once they have entered the environment, antibiotics can affect natural microbial communities. The latter play a key role in fundamental ecological processes, most importantly the maintenance of soil and water quality. In fact, they are involved in biogeochemical cycling and organic contaminant degradation thanks to their large reservoir of genetic diversity and metabolic capability. When antibiotics occur in the environment, they can hamper microbial community structure and functioning in different ways and have both direct (short-term) and indirect (long-term) effects on microbial communities. The short-term ones are bactericide and bacteriostatic actions with a consequent disappearance of some microbial populations and their ecological functioning. The indirect impact includes the development of antibiotic resistant bacteria and in some cases bacterial strains able to degrade them by metabolic or co-metabolic processes. Biodegradation makes it possible to completely remove a toxic compound from the environment if it is mineralized. Several factors can influence the significance of such direct and indirect effects, including the antibiotic's concentration, the exposure time, the receiving ecosystem (e.g. soil or water) and the co-occurrence of other antibiotics and/or other contaminants. This review describes the current state of knowledge regarding the effects of antibiotics on natural microbial communities in soil and water ecosystems.

Gemfibrozil is a pharmaceutical commonly found in the aquatic compartment and its presence together with a mixture of several other biologically-active drugs raises concern about the possible long-term adverse effects on biota chronically exposed. Most research focus on its effect/degradation in wastewater treatment plant, while few investigations take into account its persistence in receiving aquatic ecosystems and its effects on natural microbial communities. In this context, the present work aims to evaluate gemfibrozil biodegradation, alone or in the co-presence of naproxen, comparing its persistence in the presence/absence of the river natural microbial community. For this purpose, water samples were collected from a river Tiber stretch inside the city of Rome and located downstream from a wastewater treatment plant and used for degradation experiments. Microbiologically active or sterile water microcosms were set up and treated with 100 μg L− 1 of gemfibrozil alone or in the co-presence of naproxen (100 μg L− 1), in order to evaluate gemfibrozil degradation in the different conditions. At fixed times water samplings were collected for both chemical and microbiological analysis. Moreover, the effects of the pharmaceuticals on the microbial community structure in terms of variations in its abundance and composition were also assessed. The overall results showed gemfibrozil to be a quite persistent molecule in the river water microcosms and the natural microbial community had a key role in its biodegradation. The co-presence of naproxen, a non-steroidal anti-inflammatory drug commonly co-occurring with gemfibrozil, increased its persistence and affected negatively some bacterial groups presence.

Leaf transpiration drives many of the processes involved in phyto-technologies, and it can represent a useful mechanism to remove water from different kind of storage basins presenting inorganic, organic or microbiological contamination (phyto-dehydration), with the aim to reduce the risk of environmental contamination. In this framework, a mesocosm-scale trial was carried out to test the capacity of different helophyte species to reduce the excess of water in an artificial pond filled with oversaturated sludge. The sludge derives from the digestion of pig slurries, presents high levels of zinc and copper and for most of the year is covered by a water layer of about 20 cm due to rainfalls. This layout (water layer over the sludge) was reproduced inside the mesocosms, where four helophyte species (Phragmites australis and a mix of Carex acutiformis, Iris pseudacorus and Juncus effusus) were planted on floating frames. Plant growth and functionality were monitored for one year, along with their water consumption capacity; the vegetation impact on sludge chemistry, sludge microbial community and sludge greenhouse gases emission/uptake were also evaluated. The sensitivity of the phyto-dehydration system to the reduction of water level occurring during summer in the pond was investigated reducing the water input to the mesocosms. P. australis and C. acutiformis successfully established in the mesocosms, while a significant mortality was recorded for I. psudacorus and J. effusus. Once established, plants were able to grow in the mesocosms, and no metal toxicity effect was observed on photosynthesis rates that were comparable with values reported for natural stands of the species. Plants significantly increased (from 24 to 63%, depending on the species) the amount of water lost by the mesocosms and counteracted the reduction of sludge organic carbon that could lead to a mobilization of the heavy metals bound to organic matter: furthermore, plants decreased the rates of mesocosm greenhouse gas emission and reduced the sludge pathogen (Enterobacteriaceae) occurrence. Water limitations reversibly reduced the water consumption and CO2 uptake capacity of the mesocosms. The results of this study demonstrated that the water balance of a sludge/water system can be effectively modified through the phyto-dehydration approach, increasing significantly the amount of water lost. Although the low tolerance of two species to the sludge/water environment after plantation needs to be further investigated, this phyto-technology can represent a promising approach to manage the excess of water in polluted ponds.

The anionic surfactant sodium lauryl ether sulphate (SLES) is the main component of most commercial products used for soil conditioning in the excavation industry, in particular as lubricants for mechanized tunnelling. Its use during the excavation processes can result in either the subsequent possible re-use of the huge amount of soil debris as by-products (e.g. land covering) or its discharge as waste. Currently, there are neither SLES soil threshold limits in European legislation, nor comprehensive studies on the environmental risk for soil ecosystems in these exposure scenarios. In this context, the present paper reviews the available data on the intrinsic characteristics of persistence and the ecotoxicological effects of the anionic surfactant SLES. Although SLES is generally reported to be biodegradable in standard tests, with degradation rates between 7 h and 30 days, depending on the initial conditions, data on its biodegradation in environmental studies are quite scarce. Consequently, assessing SLES biodegradation rates in field conditions is crucial for evaluating if in residual concentrations (typically in the range 40–500 mg/kg in excavated soils) it can or not be a potential hazard for terrestrial and water organisms. Laboratory ecotoxicological tests pointed out detrimental effects of SLES for aquatic organisms, while data on the terrestrial species are rather poor so far and further studies at the expected environmental concentrations are necessary. Finally, the review reports the main analytical methods available for detecting anionic surfactants in solid matrices and the future research needed to improve knowledge on the possible environmental risks posed by the use of SLES in foaming agents for mechanized tunnelling.

Pollution of soil and water environments is mainly due to different anthropogenic factors and the presence of organic contaminants, in particular persistent, bioaccumulative and toxic ones, arouses concern for their possible effects on environment and human health. One nature-based technology that can be used in biodegradation of contaminated soil and water is the microbial fuel cell (MFC). They are also capable of producing energy and of being used as environmental sensors. In this context, this article aims at presenting the capacity of MFCs to reduce environmental pollution by exploiting the process of bioelectrochemical utilisation of organic matter via microbial metabolism, to generate usable by-products, fuels and bio-electricity. The main characteristic of an MFC, when used for energy harvesting, is the absence of emissions of pollutant gases like CO, CO2, SOx, or NOx. This characteristic, together with the intrinsic capacity of bioreactors to decontaminate soils and water, is stimulating the research into engineering solutions exploiting the MFC potential. Among the different types of MFCs, as bioelectrochemical systems (BESs), the terrestrial microbial fuel cells (TMFC) and the wastewater microbial fuel cells (WWMFC) convert energy using a biocatalysts (microorganism) and a biofuel (organic substrate) in basic environments such as soil and water. Consequently, MFCs can be used as energy sources for powering sensors with low power and low voltage characteristics or complete single nodes of a distributed wireless sensor network (WSN), if coupled with smart although more complex electronic circuit. Moreover, MFCs can be environmental sensors, suited to monitor some environmental parameters influencing MFC functional behaviour like as pH and temperature. This article introduces the scenarios of polluted environments where these technologies suitably could be applied together with the description of two main type of MFC structures and their functioning. Furthermore, some case studies in which MFCs are used in decontamination of polluted environments are described.

Polychlorinated byphenyls (PCBs) are a class of Persistent Organic Pollutants extremely hard to remove from soil. The use of plants to promote the degradation of PCBs, thanks to synergic interactions between roots and the natural soil microorganisms in the rhizosphere, has been proved to constitute an eective and environmentally friendly remediation technique. Preliminary microcosm experiments were conducted in a greenhouse for 12 months to evaluate the capacity of the Monviso hybrid poplar clone, a model plant for phytoremediation, to grow in a low quality and PCB-contaminated soil in order to assess if this clone could be subsequently used in a field experiment. For this purpose, three dierent soil conditions (Microbiologically Active, Pre-sterilized and Hypoxic soils) were set up in order to assess the capacity of this clone to grow in the polluted soil in these dierent conditions and support the soil microbial community activity. The growth and physiology (chlorophyll content, chlorophyll fluorescence, ascorbate, phenolic compounds and flavonoid contents) of the poplar were determined. Moreover, chemical analyses were performed to assess the concentrations of PCB indicators in soil and plant roots. Finally, the microbial community was evaluated in terms of total abundance and activity under the dierent experimental conditions. Results showed that the poplar clone was able to grow eciently in the contaminated soil and to promote microbial transformations of PCBs. Plants grown in the hypoxic condition promoted the formation of a higher number of higher-chlorinated PCBs and accumulated lower PCBs in their roots. However, plants in this condition showed a higher stress level than the other microcosms, producing higher amounts of phenolic, flavonoid and ascorbate contents, as a defence mechanism. Keywords: natural-based remediation strategies; Monviso clone; plant physiology; antioxidant

The groundwater behavior at a municipal solid waste disposal dump, located in Central Italy, was studied using a multi-parameter monitoring over 1 year consisting of 4 seasonal samples. The hydrological and hydrogeological dynamics of water circulation, microbiological parameters (microbial abundance and cell viability of the autochthonous microbial community), dissolved organic carbon, and several contaminants were evaluated and related to the geological structures in both two and three dimensions and used for geostatistical analysis in order to obtain 3D maps. Close relationships between geological heterogeneity, water circulation, pollutant diffusion, dissolved organic carbon, and cell viability were revealed. The highest cell viability values were found with dissolved organic carbon (DOC) values &le, 0.5 mg/L, above this value, DOC negatively affected the microbial community. The highest DOC values were detected in groundwater at some sampling points within the site indicating its probable origin from the waste disposal dump. Although legislation limits for the parameters measured were not exceeded (except for a contaminant in one piezometer), the 1-year multi-parameter monitoring approach made it possible to depict both the dynamics and the complexity of the groundwater flux and, with &ldquo, non-legislative parameters&rdquo, such as microbial cell viability and DOC, identify the points with the highest vulnerability and their origin. This approach is useful for identifying the most vulnerable sites in a groundwater body.

BACKGROUND: The Monviso clone previously tested successfully to remediate a lindane‐contaminated soil in central Italy was then applied in a historically heavy metal contaminated area in southern Italy. RESULTS: The results obtained at 900 days from the poplar planting showed a strong decrease below Italian national legal limits (D.Lgs 152/06) for most heavy metals (HMs). The highest reduction of HM concentrations was observed in soil samples collected near the trunk (25 cm distant from poplar) and in the rhizosphere. The values of the HM bioaccumulation factor (BAF, considering roots and leaves) and of the translocation factor (TF) suggest that poplar trees were able to phytostabilize HMs. The soil organic carbon content increased compared to the previous sampling in all plots planted. The highest values were observed for the rhizosphere soils of each target tree, while the phosphorous available strongly decreased. Microbial results showed an overall increase in cell viability, dehydrogenase activity and microbial abundance of some bacterial groups. CONCLUSION: Overall results showed that the poplar‐based phytoremediation strategy was able to promote the phytostabilization of the HMs and to improve the soil quality in terms of both organic carbon content and microbial community structure and activity. © 2019 Society of Chemical Industry

Most of the Earth’s surface (71%) is covered with water, and the oceans hold about 96 [...]

Polychlorinated biphenyls (PCBs) are ubiquitous and persistent organic pollutants generated exclusively from human sources and found in the environment as several congeners (e.g. Apirolio, produced in Italy and used for electrical transformers). To evaluate the ability of the natural microbial community of historically PCB-contaminated soil to transform or degrade PCBs after fresh contamination through the addition of Apirolio, a microcosm experiment was conducted in a greenhouse for approximately 8 months. Compost and Medicago sativa (alfalfa) were additionally used in the microcosms to stimulate microbial PCB degradation. Chemical analyses were performed to evaluate PCB concentrations in the soil and plant tissue. Changes in the microbial community under the different experimental conditions were evaluated in terms of total abundance, viability, diversity, and activity. Interestingly, the addition of Apirolio did not negatively affect the microbial community but did stimulate the degradation of the freshly added PCBs. The plant and compost copresence did not substantially increase PCB degradation, but it increased the microbial abundance and activity and the occurrence of ?-Proteobacteria and fungi.

The Water Framework Directive (WFD) regulates freshwater and coastal water quality assessment in Europe. Chemical and ecological water quality status is based on measurements of chemical pollutants in water and biota together with other indicators such as temperature, nutrients, species compositions (phytoplankton, microalgae, benthos and fish) and hydromorphological conditions. However, in the current strategy a link between the chemical and the ecological status is missing. In the present WFD, no microbiological indicators are foreseen for integrating the different anthropogenic pressures, including mixtures of chemicals, nutrients and temperature changes, to provide a holistic view of the freshwater ecosystem water quality. The main aim of this work was to evaluate if natural microbial populations can be valuable indicators of multiple stressors (e.g. chemical pollutants, temperature, nutrients etc.) to guide preventive and remediation actions by water authorities. A preliminary survey was conducted to identify four sites reflecting a contamination gradient from the source to the mouth of a river suitable to the objectives of the European Marie Curie project, MicroCoKit. The River Tiber (Italy) was selected as a pilot case study to investigate the correlation between bacteria taxa and the chemical status of the river. The main physicochemical parameters, inorganic elements, organic pollutants and natural microbial community composition were assessed at four selected sites corresponding to pristine, agricultural, industrial and urban areas for three consecutive years. The overall chemical results indicated a correspondence between different groups of contaminants and the main contamination sources at the selected sampling points. Phylogenetic analysis of the microbial community analyzed by Fluorescence In Situ Hybridization method (FISH) revealed differences among the four sampling sites which could reflect an adaptive bacterial response to the different anthropogenic pressures.

Remediation of polluted soils using phytoremediation techniques is an effective strategy. However, the use of the biomass from these soils for energy purposes may raise efficiency and pollution emission problems and there is currently little research on this issue. In this work, the main results of a fluidized-bed gasification treatment conducted on poplar biomass pruning residues from a multi-contaminated area are presented. The samples were collected from an experimental site in which a plant-assisted bioremediation (PABR) technology has been applied since 2013 to reduce the soil heavy metal (HM) and polychlorinated biphenyl (PCB) contents. The main goal of this study was to identify the specific treatment necessary, in addition to conventional tar reforming, for trapping possible residues of HMs and PCBs in ashes during the gasification process. In our study, we demonstrate that gasification of contaminated biomass coming from PABR (where contaminant residues are concentrated mainly in the roots and are insignificant in the shoots) produces syngas whose characteristics are similar to those obtained using non-contaminated biomass. The results showed that contaminant concentrations in the prunings were negligible; the total amount of PCBs was 1.63 ng/g, while HMs ranged from 0.01 to 0.70 mg/kg, except for Cu and Zn (∼20 mg/kg). Furthermore, the presence in the biomass of Ca and traces of other metals showed a possible catalytic effect with an improvement in the tar conversion in the gasifier leading to a reduction of 5–10% in tar content. The overall results suggest that a specific treatment for pollutant capture is necessary only when the roots, the part of the plants where these contaminants are concentrated, are sampled and used for the gasification process. Although energy from biomass produced on a contaminated site is currently considered waste and involves disposal costs, this paper shows that the poplar biomass grown on a multi-contaminated soil can be used for energy purposes without any impact on the environment.

We studied the changes in structure and functioning of the microbial community in a degraded agricultural soil after the addition of two composts, obtained from cattle manure or pig slurry anaerobic digestate, and the use of rosemary plants for restoring soil quality. The composts were added at low or high doses to soil samples (30 or 60 t ha − 1 , respectively), which were kept in microcosms for 6 months. Some soil microcosms were treated with inorganic fertiliser and other non-treated soils were used as microbiological controls. Rosemary plants, used both for their ability to grow in semi-arid regions and for the capacity of their root system to protect soil from erosion, were planted in half of the entire microcosm set up. At different times (0–180 days) microbial abundance and dehydrogenase activity were measured in the various experimental treatments. Total and water-soluble soil organic carbon and nitrogen contents were assessed at 0 and 180 days. With an increase in carbon and nitrogen soil content, a rise in microbial abundance was also observed in the presence of both composts. However, microbial activity was significantly influenced by the presence of rosemary, without considering the allochthonous carbon and nitrogen input. Microbial community structure and diversity were also assessed by Fluorescence In Situ Hybridization in the different treatments. The highest values for microbial community biodiversity were found in the co-presence of rosemary and at low concentrations of both composts. The overall results suggest that the use of composts together with plant species suited to Mediterranean areas seems to be an appropriate strategy for restoring soil quality and the ecosystem services provided by microorganisms.

Soil and water microorganisms play an important role in maintaining ecosystem environmental quality. In fact, the ability of soil and water to recover from chemical contamination is primarily dependent on the presence of a microbial community with the ability to remove it. In this way, the microbial community represents an important key to understanding the impacts of environmental and anthropogenic factors on ecosystems. The presence of an abundant and varied microbial community is a necessary prerequisite for an immediate and effective response to the various natural and anthropic disturbances that can affect an ecosystem. Soil and water microcosm studies enable the studying, under controlled conditions, of the effects of selective pressures, such as xenobiotic occurrence on natural microbial communities. In this paper the main data (in terms of chemical persistence and bacterial abundance) of several microcosm degradation studies performed using natural soil and water were collected and discussed. The biotic and abiotic degradation of several contaminants (including the parent compounds of pesticides and pharmaceuticals and their metabolites) was evaluated comparing microbiologically active microcosms treated with the chemical with others previously sterilized. Moreover, in some cases additional microcosms were also used for evaluating the effect of some amendments (such as urea or wood amendments) on microbial degradation. The disappearance time of 50% of the compound applied (DT 50 ) was evaluated for each chemical in the presence/absence of the natural microbial community in 19 microcosm experiments, performed using 16 different chemicals considered environmental contaminants. The overall results presented here show the key role of microorganisms in the degradation of all the chemicals studied and establish the relationship between degradation and the role of microbial communities in chemical disappearance from the environment, thus demonstrating the suitability of the of the microcosm approach for reproducing more realistic environmental exposure scenarios in the laboratory.

Ecosystem services are the contributions that ecosystems provide to human well-being. They arise from the interaction of biotic and abiotic processes, and refer specifically to the ‘final’ outputs or products from ecological systems. Soil harbours a large proportion of Earth's biodiversity, and provides the physical substrate for most human activities. Although soils have been widely studied and classified in terms of physical and chemical characteristics, knowledge of soil biodiversity and functioning are still incomplete. Soil organisms are extremely diverse and contribute to a wide range of ecosystem services that are essential to the sustainable functioning of natural and managed ecosystems. Microbial communities (mainly composed by Bacteria, Archaea and microfungi) are vital to soil ecosystem functioning. This is because they exist in enormous numbers and have an immense cumulative mass and activity. Most of the phenomena observed in the visible aboveground world are steered directly or indirectly by species, interactions, or processes in the belowground soil. In particular, being microbial communities involved in nutrient cycling and organic matter degradation, they can affect biodiversity and productivity of aboveground ecosystems. Microorganisms can have stimulating or inhibiting effects on plants by the release of metabolites with a varying range of activities. Microbial communities are the main responsible of soil homeostatic capabilities removing contaminants and providing key ecosystem regulating and supporting services such as soil fertility, resilience and resistance to different stress. This chapter aims at describing the contributions provided by soil microbial communities to different ecosystem services and their potential use as indicators of ecosystem functioning. Understanding ecosystem functioning and predicting responses to global changes calls for much better knowledge than we have today about microbial processes and interactions, including those with plants in the rhizosphere.

Plant-based clean up technologies are gaining popularity as a sustainable solution to contaminated soil remediation. In particular, plant-assisted bioremediation or phyto-assisted bioremediation exploits the synergistic action between plant root systems and natural microorganisms (bacteria and fungi) to remove, convert or contain toxic substances in soils, sediments or water. It can be applied successfully to contaminated areas. It relies on the use of a selected appropriate plant species for stimulating the biodegradation activity of natural soil microorganisms in the rhizosphere (e.g. through root exudates production or oxygen transport). Plant species can also produce extracellular enzymes that directly transform contaminants and/or make them more bioavailable. Moreover, they can also phyto-contain them. In selecting the plant species, the specific contaminant/s to be removed, and the local geopedological and climatic conditions need to be considered. Beyond the contaminant removal, there are additional benefits such as soil quality improvement, soil carbon sequestration and biomass production for energy purposes. The difficulties in remediating areas characterized by multiple pollutant occurrence (e.g. organic and inorganic toxic compounds) make the study of plant-microbial interactions important if sustainable soil recovery strategies are to be achieved. Consequently, in recent years, several plant species have been tested for stimulating natural microbial communities and supporting the remediation of contaminated soils. Among these, the poplar tree can be considered suitable for plant-assisted bioremediation purposes. In this chapter an example of the methodological approach used for its application to an area multi-contaminated (by polychlorinated biphenyls and heavy metals) is illustrated.

A preliminary ecological characterisation of an open quarry that had been used for the disposal of pharmaceutical wastes from a factory producing antibiotics was performed. Pharmaceutical wastes and groundwater samples were collected and analysed in order to assess both the bacterial community structure and functioning, and the contamination by organic compounds, including antibiotics. Bacterial abundance measured using the epifluorescence direct count method, cell viability measured by using two fluorescent dyes, species diversity measured by assessing the bacterial community structure using fluorescence in situ hybridisation (FISH) and soil microbial activity based on dehydrogenase activity were used as microbiological indicators to evaluate the ‘quality state’ of the area studied. The overall results show that groundwater has a low-quality state in terms of bacterial viability, activity and diversity, associated with trace contamination by antibiotics and chlorinated volatile organics.

This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original DOI. On 3 October 2007, 40 participants with diverse expertise attended the workshop Tamiflu and the Environment: Implications of Use under Pandemic Conditions to assess the potential human health impact and environmental hazards associated with use of Tamiflu during an influenza pandemic. Based on the identification and risk-ranking of knowledge gaps, the consensus was that oseltamivir ethylester-phosphate (OE-P) and oseltamivir carboxylate (OC) were unlikely to pose an ecotoxicologic hazard to freshwater organisms. OC in river water might hasten the generation of OC-resistance in wildfowl, but this possibility seems less likely than the potential disruption that could be posed by OC and other pharmaceuticals to the operation of sewage treatment plants. The work-group members agreed on the following research priorities: a) available data on the ecotoxicology of OE-P and OC should be published; b) risk should be assessed for OC-contaminated river water generating OC-resistant viruses in wildfowl; c) sewage treatment plant functioning due to microbial inhibition by neuraminidase inhibitors and other antimicrobials used during a pandemic should be investigated; and d) realistic worst-case exposure scenarios should be developed. Additional modeling would be useful to identify localized areas within river catchments that might be prone to high pharmaceutical concentrations in sewage treatment plant effluent. Ongoing seasonal use of Tamiflu in Japan offers opportunities for researchers to assess how much OC enters and persists in the aquatic environment. Environmental Knowledge Transfer Network, the Worshipful Company of Water Conservators, and the Chartered Institution of Water & Environmental Management.

A plant-assisted bioremediation strategy was applied in an area located in Southern Italy, close to the city of Taranto, historically contaminated by polychlorinated biphenyls (PCBs) and heavy metals. A specific poplar clone (Monviso) was selected for its ability to promote organic pollutant degradation in the rhizosphere, as demonstrated elsewhere. Chemical and microbiological analyses were performed at the time of poplar planting in selected plots at different distances from the trunk (0.25-1m) and at different soil depths (0-20 and 20-40cm), at day 420. A significant decrease in PCB congeners and a reduction in all heavy metals was observed where the poplar trees were present. No evidence of PCB and heavy metal reduction was observed in the non poplar-vegetated soil. Microbial analyses (dehydrogenase activity, cell viability, microbial abundance) of the autochthonous microbial community showed an improvement in soil quality. In particular, microbial activity generally increased in the poplar-rhizosphere and a positive effect was observed in some cases at up to 1m distance from the trunk and up to 40cm depth. The Monviso clone was effective in promoting both a general decrease in contaminant occurrence and an increase in microbial activity in the chronically polluted area a little more than one year after planting.

In this work the degradation of the herbicides metolachlor, diuron, monuron and of the metabolites 2-ethyl-6-methylaniline (EMA), and 3,4-dichloroaniline (DCA) was assessed in laboratory experiments on microbiologically active and sterilized soils. Their leaching potentials were calculated, using Gustafson's equation, by determining their mobility (as Koc) and persistence (expressed as DT50). Lysimeter experiments were also conducted to assess the actual leaching of the studied herbicides in a cereal crop tillage area vulnerable to groundwater contamination. The data obtained from the field were compared to the laboratory results. Moreover, some compounds of particular concern were searched for in the groundwater located near the experimental area in order to evaluate actual contamination and to test the reliability of the leaching potential. The GUS index, computed on data from microbiologically active soil, shows monuron as a leacher compound, EMA and DCA as non-leachers, metolachlor and diuron as transient ones. The presence of metolachlor in the groundwater monitored, even at concentrations up to 0.1 μg/l, confirms the possibility that transient compounds can be leached if microbial activity has not completely occurred in active surface soil.

The concern on the presence of pesticides in Italian water resources historically broke out around 1980 after severe episodes of ambient, raw water and drinking water contamination due to some herbicides, atrazine (ATR), its metabolites desethylatrazine (DEA) and deisopropylatrazine (DIA), simazine, cyanazine, bentazone, molinate, which affected mainly the maize, grain and rice producing floodplains and karst areas of the northern Regions. Due to the risks of human exposure, in the early 1990 the use of atrazine was banned in Italy and was replaced by terbuthylazine (TERB). In a few years, TERB became a chemical of concern, together with its main metabolite desethylterbuthylazine (DET), because of alerting detections in surface and groundwater resources. Up to now, the risk of contamination of water resources by TERB, DET, DEA and, in some extent ATR, is of relevance in Italy due to their present and past wide employment in agriculture, the discharges or seepages in particularly vulnerable areas, their unfavorable intrinsic properties, e.g. poor sorption and high persistence, their mobility by drift, leaching and runoff in vadose zones, aquifers and surface water. So, unsurprisingly, results from national monitoring of ambient water and raw water indicate that TERB, DET, DEA and residual ATR, despite its withdrawal, are detected at remarkable frequencies and, sometimes, at levels higher than pesticide quality standards under the Italian Decrees for the protection of surface water (specifically, raw waters doomed at the drinking water abstraction), groundwater and drinking water (tap water), that is 0.1–0.5 μg/l for individual pesticides and for total pesticides, respectively, including relevant metabolites. On the other hand, in these last years, the control measures in drinking water production adopted by the waterworks Companies and the regional and central health Authorities, also in the view of the recent WHO approaches under the Water Safety Plans, ensure that levels of any pesticide residue (also involving TERB, DET, DEA, ATR) in finished tap water meet parametric values for pesticides. Therefore, in these last years, no derogation to the parametric values for drinking water has been required. The aim of this paper is to contribute to widen the knowledge on the water impact of these important water pollutants giving sound details on present usages, levels and frequencies of detection in water bodies in Italy, on their key chemiodynamic properties, e.g. soil half-lives (DT50) and soil to organic carbon partition (Koc) available in the open literature, particularly for TERB metabolites, and some details on legal provision adopted at the national level. In fact, a more effective protection of water supplies, particularly against TERB and DET, has been pursued in the late 2000s by the Italian Health Ministry through the adoption of consistent provisions aimed at mitigating emissions of TERB in routine agricultural activities, and by the Italian Ministry of the Environment through the adoption of specific Environmental Quality Standards for TERB and its metabolite DET, ATR, SIM for the protection of surface waters.

Pesticide and nitrate contamination of soil and groundwater from agriculture is an environmental and public health concern worldwide. The herbicide terbuthylazine (CBET) has replaced atrazine in Italy and in many other countries because the use of the latter has been banned because of its adverse environmental impacts. Unlike atrazine, knowledge about the fate of CBET in soil is still not extensive, especially regarding its transformation products, but recent monitoring data show its occurrence and that of its main metabolite, desethyl-terbuthylazine (CBAT), in groundwater above the limit of 0.1 microg/L established by European Union Directive and Italian legislation. The objective of this work was to investigate if the presence of the fertilizer urea affects CBET degradation in the soil. Laboratory CBET degradation experiments in the presence/absence of urea were performed with microbiologically active soil and sterilized soil. Terbuthylazine degradation rates under the different experimental conditions were assessed, and the formation, degradation, and transformation of the metabolite CBAT were also studied. Terbuthylazine degradation was affected by the presence of urea, in terms both of a higher disappearance time of 50% of the initial concentration and of a lower amount of CBAT formed. These findings have practical implications for the real-life assessment of the environmental fate of triazine herbicides in agricultural areas since these herbicides are frequently applied to soils receiving ureic fertilizers.

Microbial communities are valuable indicators of the occurrence of disturbances due to exogenous physico-chemical stressors. The assessment of variations in microbial community structure is of basic importance to permit to evaluate the impact of an environmental stressor. Complex microbial communities may serve as ideal and ecologically relevant toxicity indicators. A number of microbiologically driven processes have been proposed to evaluate the effects of xenobiotics on ecosystems. Proteins, genes, metabolites, or lipids that, when expressed, present a pattern of molecular change in an organism in response to a specific environmental stressor, can be defined as environmental biomarkers. The number of techniques to study microbial communities has increased exponentially over the last 20 years and the advent of culture-independent methods, such as molecular biological techniques, has changed the view of microbial diversity. Among these techniques epifluorescence microscopy techniques, such as direct count of bacterial abundance (DAPI count) and viability (Live/Dead cell viability assay), and Fluorescence In Situ Hybridization (FISH) are very useful to study microbial communities directly from their natural environment. We report some examples of application of these techniques for evaluating the effects of some contaminants (pesticide and pharmaceuticals) to soil and water ecosystems.