Environmental pollution caused by heavy metals has long been considered a relevant threat to ecosystem survival and human health. The use of safer substitutes for the most toxic heavy metals in many industrial applications is discussed as a potential way to face this issue. In this regard, Bi has been proposed for replacing Pb in several production processes. However, few literature records reported on the effects of Bi on living organisms, particularly on plants. In this study, garden cress (Lepidium sativum L.) plants were exposed to different concentrations of Bi nitrate added to soil in growth chambers for 21 days. Results evidenced the toxic effect of Bi on shoot growth, regardless of the Bi nitrate concentration in the soil, paralleled by a similar reduction in the chlorophyll and carotenoid content, a decrease in the nitrogen balance index values, and an impairment of the photosynthetic machinery evaluated by chlorophyll fluorescence image analysis. The presence of Bi in the soil was shown to affect element accumulation in roots and translocation to shoots, with micronutrient content particularly reduced in the leaves of Bi-treated plants. A dose-dependent plant accumulation of Bi to metal concentration in the soil was observed, even if very low metal bioconcentration ability was highlighted. The reduced Bi translocation from roots to shoots in plants exposed to increasing Bi concentrations in the soil is discussed as a possible defense mechanism likely associated with the observed increase of anthocyan and flavonol contents and the activation of photoprotection mechanisms preventing higher damages to the photosynthetic apparatus.

Pyrolysis is considered as a suitable thermochemical treatment when the biomass sources are contaminated by potentially toxic elements (PTEs). More than the type of the feedstock, the pyrolysis operating conditions are the key parameters affecting the transformation of PTEs during the thermal treatment and the migration and distribution to the pyrolysis end-products. By a proper choice of the pyrolysis conditions is able to concentrate the PTEs in the solid product (biochar) leaving the vapor phase (bio-oil) free of heavy metals thus enabling its use as a fuel. Pyrolysis temperature is the main variable affecting PTEs concentration and recovery in the biochar in a more thermally stable form than those found in the original biomass. At lower temperature PTEs are confined in the biochar, and their concentration increases with the temperature, whereas 550-700°C is the optimal range for producing biochar with both high porosity but less PTEs concentration. Moreover, high porosity and surface area allow to suggest the opportunity to evaluate the valorization of biochar in different application fields (fertilizer, activated carbons precursor, filler in wood and polymer composites, contaminants adsorbent in wastewater and soil, floating cover). A key aspect for the enriched PTEs biochar application is the assessment of its toxicity related to the PTEs mobility and bioavailability. To the best of our knowledge, temperature and heating rate are already faced out for the PTEs behavior, but there is still a knowledge gap concerning their fate under different pyrolysis reaction environments. To this aim, in the present study lignocellulosic biomass (populus nigra) contaminated by Pb is tested under slow pyrolysis conditions (HR=5 °C/min), and the effect of temperature (465, 550, 700 °C) and gas carrier (N2, CO2, H2O and mixture of them) are investigated on biochar properties and PTEs behavior. The risk assessment of the biochar is also performed based on the sequential extraction procedure defined by the European Community Bureau of Reference (BCR) that allows for the classification of metals in the biochar in different chemical categories.

In latest years, lignocellulosic biomass is being considered widely as an alternative energy source to fossil fuels, both for its direct utilization and, mostly, for its upgrading to more valuable biofuels through several chemical and thermos-chemical processes, among which there is the pyrolysis process. To supply the rising demand for lignocellulosic biomass while avoiding iLUC (indirect land use change) related concerns, there is the need for growing biomass also on marginal lands and contaminated soils; this practice, however, could lead to the contamination of the biomass itself by different pollutants, such as heavy metals (HMs). The presence of heavy metals in the biomass structure could hinder both its processing through pyrolysis and the subsequent use of the potentially contaminated pyrolysis products. The aim of this work is to evaluate the fate of HMs during contaminated lignocellulosic biomass pyrolysis both in terms of HMs distribution between pyrolysis products and HMs chemical transformations; moreover, it has to be considered that the presence of HMs can also modify the yields and properties of pyrolysis products. The experimental campaign tested a variety of combinations of pyrolysis temperatures (i.e. 450, 600 and 800 °C) and biomass pretreatments (i.e. untreated or doped with HMs salts) for a total of 9 pyrolysis tests. The employed biomass is a poplar (Populus nigra) that grew on contaminated land and retained naturally only a small amount of lead (20 ppm). To better trace the HMs during pyrolysis, the poplar biomass was doped via wet impregnation with two different lead salts, lead acetate and lead nitrate, to achieve a much higher concentration of lead (nominal concentration = 1000 ppm). Moreover, by using two different salts, information can be gained on the effect of the starting chemical form of HMs on their fate during pyrolysis. All the pyrolysis tests are conducted in a jacketed slow pyrolysis reactor [1] which allows for finely controlling the final temperature and heating rate, while also minimizing the elutriation of solid biomass/char particles toward the condensation section at the exit of the reactor. All the pyrolysis solid and liquid products, as well as the untreated and doped biomass, are characterized extensively in their physical-chemical properties such as elemental composition, moisture and ash content, pore content and pore size distribution. Among the various analytical techniques, the ICP-MS (Induced Coupled Plasma Mass spectroscopy) represents a key tool for the purpose of this work, since it detects HMs in the biomass and pyrolysis products at ppm levels, granting the possibility to track lead displacement during pyrolysis. Another analytical technique that, despite being applicable only to solid samples (biomass and char), can give useful information is the BCR sequential extraction. This technique consists of a sequence of extractions carried out with different solvents characterized by a growing degree of aggressivity: each solution removes some specific metal compounds so that useful hints on the speciation of HMs (and in particular of lead) can be gained from the ICP-MS analysis of the leachates and of the final solid residue. In summary, the present work aims to shed light on the basics of heavy metals beahviours and transfer mechanisms during the pyrolysis of HMs contaminated lignocellulosic biomass. Moreover, the possible effects of HMs on pyrolysis products yield and properties are also considered.

Air pollution and the increasing production of greenhouse gases has prompted greater use of renewable energy sources; the EU has set a target that the use of green energy should be at 32 percent by 2030. With this in mind, in the last 10 years, the demand for pellets in Italy has more than doubled, making Italy the second largest consumer in Europe. The quality of the pellets burned in stoves is crucial to indoor and outdoor pollution. Among other parameters, moisture and ash are used to classify pellets according to EN ISO 17225:2014. This work involved the analysis of the organic and inorganic fraction of both some finished products on the Italian market and some raw materials (e.g., wood chips) sampled according to the technical standard EN 14778:2011. The analytical results showed the presence of some substances potentially harmful to human health such as formaldehyde, acetone, toluene and styrene for the organic fraction and nickel, lead and vanadium for the inorganic fraction. The chemometric approach showed that it is the inorganic fraction which is most responsible for the diversification of the samples under study. The detection of some substances may be a warning bell about the impact of such materials, both for the environment and for human health.

The present work is aimed at the scale up of CrioPurA, a chelating material that is used in water treatment for the removal of toxic metals such as chromium, boron, and arsenic, with higher efficiencies than current competitors. The advancement of the TRL (Technology Readiness Level) of the proof-of-concept material to levels 5-6 concerns the study of environmental sustainability in relation to the economy of production, and the possible alternative methods of use. The scaling up was carried out on the synthesis of 4-vinyl-benzyl chloride with N-methyl-D-glucamine, a reaction that leads to the formation of the monomer 4-vinyl-benzyl-N-methyl-D-glucamine (VbNMDG). The synthesis of the monomer, used for the cryo-polymerization of the filtering material, has been modified to allow greater environmental sustainability and cost-effectiveness of the process. Specifically, methanol, used as a solvent for monomer synthesis, was recycled with a 10% loss. Furthermore, on a laboratory scale1,2, the purification of the monomer takes place by crystallization from CHCl3. During the scale-up, this step was advantageously eliminated. The subsequent polymerization process was therefore reviewed in terms of stoichiometric ratios of the reactants, to achieve reaction yields and chemical-physical properties like those tested for the proof of concept 1, 2. The scale-up process was carried out gradually, going through three intermediate steps, up to 1 kg of production, obtaining an 80% yield. Finally, CrioPurA was tested in a demonstrator purposely made to allow flow tests up to a flow rate of 300 liters/hour by varying the load of polluted water. The product obtained by applying the new protocol was also analyzed at different pH values, comparing the data obtained with those of the main competitors on the market. The advancement of the TRL of the CrioPurA material has allowed the design of alternative and more sustainable synthetic roads both in economic and environmental terms. The material has been successfully tested both in batch and flow, at different pH values and using polluting loads of organic nature.

N-methyl-D-glucamine (NMG) is a chelating molecule used for environmental purposes for its high efficiency and selectivity versus metal ions species. The technology namely CrioPurA regards the realization of NMG-based hydrogels, produced by cryo-polymerization in water. The synthesis of ad-hoc functionalized polymeric materials with chelating groups is a sustainable and low-cost strategy to obtain adsorbent materials. In particular, the technique adopted for the realization of material allows to obtain different structures as well as shapes of different sizes, with high porosity, permeability and excellent sequestering action towards boron, arsenic, chromium and other metals ions from the water. CrioPurA can be regenerated, reused and adapted to existing water treatment plants

This chapter covers the natural occurrence of potentially toxic elements in the environment, particularly geological sources, and their impact on groundwater quality. The toxicity of the main elements is covered, as well as guidelines to their toxicity and the control limits in drinking water. Finally, the main methods for the removal of toxic elements from groundwater, drinking water, and wastewater are covered, as many of the methods are the same, and the overarching goal of each is the protection and health of the hydrosphere.

Environmental conditions (temperature and soil water content) and pollutants (N depositions) strongly affect decomposition rates of organic matter and nutrient cycling in urban soils. In this study, we evaluated to what extent the soil physical and chemical properties were impacted by urban and peri-urban conditions in Pisa (Italy), a small medieval city with narrow streets that impede efficient public transport causing oversized private transport. Experimental period spanned from late-summer 2019 to spring 2020, before and after the COVID-19 pandemic lockdown in Italy. Climate and air quality were assessed throughout the experimental period. Significant differences in atmospheric NO2 concentrations between sites were maintained over time, with much higher NO2 concentration in the urban site compared to the peri-urban one. Although very often urban soils lack in organic matter, both sites showed relevant content of nitrogen (N) and organic carbon (Corg), especially in the peri-urban soil which was also more aggregated and water stable than urban soil. Interestingly, a seasonality effect on some elements (i.e., Cu and Zn) at both sites was observed, which may be due to their mobility and bioavailability in specific season. Soil organic matter in the more polluted site was enriched in 13C and 15N, possibly due to a combination of enriched urban N sources and greater soil C and N cycling rates. This was reflected in an enhanced leaf N concentration in evergreen woody species [Quercus ilex L., Nerium oleander L. and Pittosporum tobira (Thunb.) W.T. Aiton] growing in the urban site compared to the peri-urban one. This study demonstrates that, even in a small city, urban conditions influence soil properties and nutrient cycling, affecting plant nutritional status and its ability to provide key ecosystem services.

Many agricultural areas are contaminated by heavy metals to such a level that the growth of plants is drastically reduced. Based on the site's specific characteristics, feasibility studies were carried out to choose the most effective technologies. Feasibility tests showed that soil washing and phytoremediation technologies could be used at the agricultural site under study. The efficiency of the technologies is highly dependent on soil characteristics, which determine the chemical form of the metals. The results indicate that water-based soil washing can be successfully used with the possibility of reaching the remediation objectives quickly. However, the technology in the first step essentially breaks down the soil. Moreover, phytoremediation cannot be used directly to overcome the toxicity derived from the very high bioavailability of the heavy metals. Still, there is the need to use "assisted" phytoremediation by adding compost that reduces metal bioavailability, allowing phytoextraction. In this case, a longer time is needed to reach the remediation target. The results provide a preliminary scenario for decision-makers and stakeholders to assess possible technologies applicable and a possible scheme to be applied in similar cases of polluted agricultural areas.

Esposizione dell'evoluzione della tecnologia "CrioPurA

CERESiS (ContaminatEd land Remediation through Energy crops for Soil improvement to liquid biofuel Strategies) project, granted under EU Horizon2020 research and innovation programme, intends to promote land decontamination through phytoremediation by growing energy crops to produce clean biofuels. In this context, the project aims to demonstrate the potential of two thermochemical processes, i.e. Supercritical Water Gasification (SCWG) and Fast Pyrolysis (FP) for the production of key bio-fuel precursors suitable for further upgrading from contaminated biomass. The aim of our research activity is to design a FP system which allows to obtain at the same time high yields and low levels of contaminants in the bio-oil. The auger reactor configuration was chosen. The advantages of using an auger reactor are summarized as follows: oProven technology. oWide range of particle sizes that can be processed. oGood control of residence time and temperature. oGood mixing characteristics. In contrast, the main disadvantage is the high cost of maintenance required, given the presence of moving parts and possible tar condensation on the shaft when an auger reactor heated only indirectly through the external wall is used. To deal with tar condensation problems the reactor is heated by three independent induction heaters that allow reaching high heating rates of the shaft with great efficiency. A two-stages fractionated condenser, a cyclone and an electrostatic precipitator are used to selectively capture solids and condensable products. The auger reactor was designed to valorize contaminated biomass coming from phytoremediation adapting the plant and operational parameters to the presence of inorganic contaminants. Both pelletized and ground contaminated biomass can be used as feedstock for bio-oil production. Further investigations are needed to assess the possible effect of feedstock size on pyrolysis products yields and heavy metals speciation and distribution.

Critical raw materials (CRMs) can be defined as materials of which the risks of supply shortage and their impacts on the economy are higher compared to most of other raw materials. The European Commission (EU) has created the three lists of CRMs for the EU (in 2011, 2014 and 2017). To tackle the supply risk challenge, innovation is required with respect to sustainable primary mining, substitution of critical metals, and urban mining. In these three categories, bio-hydrometallurgy can play a crucial role.

This article highlights recent experimental advances in the use of inorganic substances in the encapsulation of pollutants and, in particular, discusses the potential applicability and constraints of the geopolymerization process for the treatment of wastewater containing chromium. A great percentage of waste containing chromium salts is produced by the leather industry during the tannery process. Such industrial waste is in the form of liquor containing almost 40% of the initial chromium combined with many other pollutants. The stabilization/solidification (S/S) treatment of this type of waste must be combined with chromium encapsulation in an economic, environmentally friendly and efficient process to be industrially feasible. Here we present a novel process in which the wastewater is used as a component of the formulation together with a clay by-product and with the addition of NaOH pellets with the goal of a no-water plus no-waste technology approach. The final solidified "ceramic-like" material successfully immobilized the heavy metal cations as well as anions and macromolecules of surfactants, avoiding environmental damages to soil and groundwater. The article is completed by mentioning other S/S processes where wastewater has been treated and the resulting sludge encapsulated. The future of the S/S technologies in the tannery industry should progress in the direction of significantly reducing the amount of wastewater directed to the treatment plants, with associated reductions in transport and their CO2 emissions. This article intends to be a contribution in the direction of preventing waste, aligning circular economy and waste management objectives.

The interaction between biomass from plant assisted bioremediation processes PABR contaminated with heavy metals and the bed materials used in Fluidized Bed Gasifier FBG systems was experimentally studied to identify the origin of the metals detected in syngas and/or solid residues, and affecting the quality of the produced fuels and biochar. The characteristics of an arboreal (poplar pruning) and an herbaceous biomass (Arundo Donax), both previously used in phytoremediation processes, were evaluated. The bed materials have been identified among those most used in pyrogasification processes, such as olivine, K-feldspar, kaolinite and calcite. The simulation of the process and the sampling of the syngas was carried out by means of an instrumental apparatus composed of TGA-DSC connected with a system of bubblers for the capture of heavy metals HM. The analysis of the matrices and the bubbled solutions in ICP-MS allowed to experimentally evaluate quantity and composition of HM released. The analyses showed that calcite gives the best results for both arboreal and herbaceous biomass but it has the disadvantage of losing about 55 % in weight during the process, releasing CO and CO 2 and becoming CaO. The criteria for choosing the most suitable material for the bed of an arboreal or herbaceous biomass gasification were carried out mainly on the basis of the heavy metals released during the process. The study provides useful results for the assessment of the bed materials in FBG conversion process using PABR biomass. From a comparison between all the parameters considered and the Principal Component Analysis (PCA) results, it emerges that K-feldspar represent the best optimization for the materials that can be used in FBG beds both in the case of arboreal and herbaceous plants, while olivine is particularly effective only with arboreal biomass.

Lo studio proposto mira alla caratterizzazione geochimica delle acque e dei sedimenti del Lago di Monte Cotugno (Parco Nazionale del Pollino, Basilicata) e gli eventuali effetti sulla fauna ittica presente in esso. Le principali attività di ricerca prevedono il campionamento e la caratterizzazione geochimica e minero-petrografica dei sedimenti lacustri, il campionamento e la caratterizzazione geochimica delle acque fluviali e lacustri, l'elaborazione ed interpretazione dei dati geochimici e minero-petrografici nonché quella di dati satellitari volta alla caratterizzazione della vegetazione delle aree ripariali, il campionamento e il monitoraggio della fauna ittica destinata alla pesca nella zona in oggetto di studio, l'informazione, la sensibilizzazione e il trasferimento dei risultati. Mediante la caratterizzazione delle acque, dei sedimenti e della vegetazione della zona di immissione del fiume Sinni all'interno del Lago di Monte Cotugno, e del tratto fluviale immediatamente a monte di esso, sarà possibile definire i processi di mobilizzazione di alcuni metalli pesanti e individuare eventuali pattern di migrazione degli stessi nelle specie acquatiche.

Jellyfish as food represent a millennial tradition in Asia. Recently, jellyfish have also been proposed as a valuable source of protein in Western countries. To identify health risks associated with the potential human consumption of jellyfish as food, trace element accumulation was assessed in the gonads and umbrella tissues of the Mediterranean Rhizostoma pulmo (Macri, 1778), sampled over a period of 16 months along the shallow coastal waters a short distance from the city of Taranto, an area affected by metallurgic and oil refinery sources of pollution. Higher tissue concentrations of trace elements were usually detected in gonads than in umbrella tissue. In particular, significant differences in the toxic metalloid As, and in the metals Mn, Mo, and Zn, were observed among different tissues. The concentrations of vanadium were slightly higher in umbrella tissues than in gonads. No positive correlation was observed between element concentration and jellyfish size, suggesting the lack of bioaccumulation processes. Moreover, toxic element concentrations in R. pulmo were found below the threshold levels for human consumption allowed by Australian, USA, and EU Food Regulations. These results corroborate the hypothesis that R. pulmo is a safe, potentially novel food source, even when jellyfish are harvested from coastal areas affected by anthropogenic impacts.

Phyto-technologies are nature-based solutions that can solve contamination problems in a sustainable and economic way. This work reports the preliminary results of a microcosm experiment in plant pots for evaluating sunflower capabilities in bioremediation of a soil contaminated by polychlorinated biphenyls (PCBs) and heavy metals (HM), collected from an area close to Taranto (Apulia Region, Southern Italy). Municipal solid waste compost of high quality was also used for evaluating the possible enhancement of plant-assisted bioremediation. At the start of the experiment, chemical analyses of soil organic contaminants (PCB total congeners and sum of tri- tetra-, penta-, hexa-, and epta-CB isomeric classes together with PCB markers, dioxin-like non-dioxin-like congeners) and inorganic ones (heavy metals such as Zn, Sn and Pb) highlighted that regulatory limits were exceeded. The sunflower-assisted bioremediation is in progress and further samplings will be performed at 45 and 90 days.

Driven by the need to protect our natural water resources, our research team developed CrioPura, an innovative and sustainable technology for water purification. In particular, CrioPura is a range of polymer sponges, specifically designed and synthesised to remove selected contaminants from wastewater produced by industrial processes, providing purified water suitable to be reused or to safely return to the environment. The huge amount of fresh water used by industries every day in the world represents a major drain for the planet limited resources. Indeed, every industry withdraws thousands of tons of fresh water every day, producing wastewater with a number of contaminants. Remediation tools currently used, lack of efficiency and sustainability. By contrast CrioPura is sustainably produced by green process, using eco-friendly starting materials, obtaining recyclable products with exclusive efficiency.