The growing demand for lithium (Li) as a key component in battery production is raising concerns about the possible increase in its level in the environmental matrices. Sustainable processes for the remediation of metal-contaminated sites have been targeted, and plants could be useful for this scope. In this regard, the selection of plant material with an improved ability to tolerate and accumulate Li is required. In this work, a proof-of-concept in microshoots cultivated in vitro condition was performed to evaluate the potential of hemp (Cannabis sativa L.) to grow and accumulate Li when exposed to relevant concentrations of this metal in the medium. The results demonstrated the toxic effect of Li on plant growth even at the lowest Li level tested (50 mg L-1). Increased Li concentrations (150 and 300 mg L-1) caused an impairment of the photosynthetic machinery and an alteration of element uptake, particularly for micronutrients such as Cu, Fe, Zn, Ni, and Co. A remarkable accumulation of Li in the microshoots was detected in relation to the metal concentration in the substrate. The overall data were discussed, providing evidence for the potential of hemp plants to tolerate and accumulate Li. The results of this work could be a reference for further insights into the potential of hemp for Li phytoremediation and phytomining, although the in vitro growth conditions allow them to be highlighted as preliminary indications.

Synthetic zeolites obtained combining natural sources (bauxite and obsidian), pure alumina/silica reagents, and waste material (red mud) were tested for heavy metals (i.e., Pb2+, Zn2+, Ni2+, Cr3+) removal. The adsorption capabilities of the formed sodalite, zeolite A and zeolite X (LTA and FAU topology, respectively), were compared through thermodynamic and kinetic experiments. Although all the newly-formed zeolites were able to remove the pollutant elements within 24 h, Zeolite X and sodalite synthesized combining obsidian (natural material as silica source) and red mud (waste material as alumina source) proved to be a better sorbent phase (qmax 20-25 mg g-1) compared to Zeolite A formed from treated bauxite (qmax 4-18 mg g-1). Their removal efficiency was also evaluated in polluted waters (wastewater treatment plant [WWTP] effluent, heavy metals mixture, native pH). Depending on synthesized zeolite type, the adsorption mechanism was accredited to ion exchange and precipitation mechanisms. The location of metal-ions inside the zeolite channels was defined by X-ray Powder Diffraction (XRPD) Rietveld analysis. Host-guest interactions among the framework oxygen atoms, co-adsorbed water molecules, and metal-ions were highlighted by the refined bond distances. Finally, magnetic characterization allowed the recognize of different magnetic properties as a function of raw materials used for zeolite synthesis.

Phytoremediation is an appropriate and sustainable technology used to clean up pollutants from soils and waters through plant species. They are naturally capable of absorbing metals and degrading organic molecules, but often, the presence of contaminants causes suffering to plants driving limited growth. In these situations, thanks to the production of specific root exudates, the plants can engage the most suitable bacteria capable of supporting their growth according to the particular environmental stress. These rhizobacteria (PGPR) promote the growth and development of plants with numerous beneficial effects, even more evident when plants are grown in critical environmental conditions, such as toxic contaminants. A better and deeper understanding of the interactions between plants-microorganisms directly in the matrix of interest, especially in the presence of persistent contamination, could provide new opportunities for phytoremediation. PGPR can alleviate the phytotoxicity of metals in the soil by altering their bioavailability and increasing the translocation of metals within the plant or excluding their uptake. Lead (Pb), mercury (Hg) and arsenic (As) are among the most toxic metals (metalloids). We report some phytoextraction results with three different soils contaminated by i) As and Hg , (ii) As and iii) Pb.

Purpose: Intensive horticulture relies on non-renewable materials and creates high environmental concern due to peat overexploitation and long-distance transportation. Emerging research is therefore looking for alternative growing media. The aim of this study was to demonstrate the possibility of converting waste (dredged sediment) into a product (commercial substrate) through sustainable techniques. Methods: Sediments from the Leghorn port (Italy) were subjected to phytoremediation and landfarming before use for cultivation. Blends of treated sediment (0, 25, 50%) with standard substrates based on peat, pumice, coconut fibre, and wood fibre were used for the propagation of cherry laurel (Prunus laurocerasus) using rooted cuttings in a greenhouse and with different water regimes. Growing media were analysed just after mixing their constituents, before plant cultivation, and cherry laurel vegetative growth and physiological parameters were studied. Results: The phytoremediated sediment was successfully used as growth medium constituent in all tested media other than peat and coconut fibre in proportions varying between 25 and 50%, whereas in combination with wood fibre, it reduced cherry laurel growth and aboveground biomass. Leaf chlorophyll content and lipid peroxidation did not differ regardless of substrate mixture and water regime. Discussion: All sediment-based media showed physicochemical parameters and heavy metal content in line with Italian regulations. Although sediment-based substrates were rich in zinc, this element was found at very low concentrations in plants. Our results highlight that the treated sediment can be used as a partial substitute for standard raw materials, especially peat and coconut fibre, in container production of cherry laurel.

Fluidized-bed gasification (FBG) of Phyto-assisted Bioremediation (PABR) biomass is analyzed focusing on the contaminants' dispersion. Poplar pruning coming from an area contaminated by polychlorinated biphenyls (PCBs) and heavy metals (HM) are considered. The biomass analysis showed relevant contents in HMs, especially Cd and Cr, and no significant PCB content. FBG process was analyzed to: a) track pollutants, b) detect con taminants in the FBG and c) investigate the HMs concentration in the produced streams. The results showed that most of the metals are concentrated in the ashes collected in the bottom of the reactor (Pb, Cd, Cu, Cr), or in the cyclone (B, Na, Mg, Al, K and Fe). Interestingly, metals are also released by the olivine bed (Mg, Fe, Ni and Al) and transported downstream. Consistent fractions of Zn and Fe (also Cu) were detected in the fugitive ashes. As for the Volatile Organic Compounds (VOC) concentration, we noted similarities between PABR and virgin biomass syngas streams. A reduced-scale process was carried out in TGA-DTA to investigate the potential of such technique in reproducing the main features of the FBG process. Comparable results were obtained, thus sug gesting its possible application for small-scale preliminary assessment of FBG process.

This paper is focused on the field-evidence of environmental hazard associated with flood events in highly contaminated marine coastal areas. The Crotone site (Ionian Sea), in the 1900s hosted a large industrial settlement (with the largest plant in Europe of zinc production, phosphorus manufacture, etc.) which left a severe legacy of environmental pollution. Here, we report the results of an investigation related to the distribution of heavy metals (Zn, Pb, Cd, Cu) in 230 sediment cores that allowed a detailed reconstruction of the contamination due to the discharge at sea of industrial wastes deriving from the Zn-sulphides leaching processes. High concentrations of heavy metals (e.g., Zn > 5000 mg kg) accumulated in sediments of the seabed along coastline, exposed to the fluvial and coastal dynamics, act as a potential long-term source of pollution for the marine ecosystem. Fingerprints of historically flash flood events evidenced in two Pb dated sediment cores suggest that these catastrophic events played a crucial role in the land-to-sea transferring (and sequent dispersing effects) of highly polluted sediments. Anomalous depositions of heavy metals-rich sediments in the offshore system (4-6 km from the coastline) testify secondary contamination due to mobilization and redistribution of old contaminated sediment due to flood events. These interactions between natural and anthropic hazards trigger cumulative mechanisms of multiple-pollution and transfer of contamination from polluted nearshore to offshore nearly pristine areas trough main canyon axes.

Photosynthetic purple non-sulfur bacteria (PNB) have been widely utilized as model organisms to study bacterial photosynthesis. More recently, the remarkable resistance of these microorganisms to several metals ions called particular interest. As a result, several research efforts were directed toward clarifying the interactions of metal ions with PNB. The mechanisms of metal ions active uptake and bioabsorption have been studied in detail, unveiling that PNB enable harvesting and removing various toxic ions, thus fostering applications in environmental remediation. Herein, we present the most important achievements in the understanding of intact cell-metal ions interactions and the approaches utilized to study such processes. Following, the application of PNB-metal ions interactions toward metal removal from contaminated environments is presented. Finally, the possible coupling of PNB with abiotic electrodes to obtain biohybrid electrochemical systems is proposed as a sustainable pathway to tune and enhance metal removal and monitoring.

This paper reports the application of organic amendments, such as biochar (BC) or compost (CMP) in a Plant-assisted bioremediation (PABR) strategy of a soil contaminated by polychlorinated biphenyls (PCBs) and heavy metals (HM). BC and CMP were applied for improving PABR in specific plots where the highest amounts of PCBs were present. Before the organic treatments and six months after it, soil samples and plant tissue (leaves, shoots and roots) were collected from each investigated plot and chemical and microbiological analyses performed. Moreover, micro-X ray fluorescence (µXRF) analysis was performed on soil and biomass (leaves, roots). Preliminary results evidenced different effects of the CMP or BC on promoting PCB and HM removal, depending on the initial pollutant concentrations

The Pietra del Pertusillo freshwater reservoir is a major artificial lake of environmental, biological, and ecological importance located in the Basilicata region, southern Italy. The reservoir arch-gravity dam was completed in 1963 for producing hydroelectric energy and providing water for human use, and nearby there are potential sources of anthropogenic pollution such as urban and industrial activities. For the first time, the minero-chemistry of the lake and fluvio-lacustrine sediments of the reservoir have been evaluated to assess the environmental quality. Moreover, the composition of fluvial sediments derived from the peri-lacual zone of the reservoir and of local outcropping bedrock were also studied to understand the factors affecting the behavior of elements in the freshwater reservoir, with particular attention paid to heavy metals. In Italy, specific regulatory values concerning the element threshold concentration for lake and river sediments do not exist, and for this reason, soil threshold values are considered the standard for sediments of internal waters. The evaluation of the environmental quality of reservoir sediments has been performed using enrichment factors obtained with respect to the average composition of a reconstructed local upper continental crust. We suggest this method as an innovative standard in similar conditions worldwide. In the studied reservoir sediments, the trace elements that may be of some environmental concern are Cr, Cu, Zn, As, and Pb although, at this stage, the distribution of these elements appears to be mostly driven by geogenic processes. However, within the frame of the assessment and the preservation of the quality of aquatic environments, particular attention has to be paid to As (which shows median value of 10 ppm, reaching a maximum value of 26 ppm in Quaternary sediments), constantly enriched in the lacustrine samples and especially in the fine-grained fraction (median = 8.5 ppm).

The plant association of Populus alba L. 'Villafranca', Brassica oleracea var. acephala sebellica (kale), and B. oleracea var. capitata 'sonsma' (cabbage) was exposed to Zn, Cd, and exogenous caffeine (CFN)-contaminated water under growth chamber conditions. In the short term of treatment (15 days), poplar increased the root dry biomass (+ 25%) and decreased the chlorophyll content in new leaves (- 32%), compared to control. On the contrary, cabbage decreased the root dry biomass, enhancing the shoot dry biomass (+ 50%). Heavy metals were mainly concentrated in plant roots and in poplar reached the highest concentrations of 705 ± 232.6 and 338 ± 85.5 ?g g DW for Zn and Cd, respectively. The ability of poplar to accumulate more Zn and Cd than kale and cabbage in plant biomass was confirmed by heavy metal contents, following the order: poplar > kale = cabbage. However, poplar and Brassica sp. association was very useful for Zn and Cd decontaminations as reported by the bioconcentration factors (> 1). The concentration of CFN was below 2.4 ng g FW in poplar and 7.4 ng g FW in Brassica species, suggesting the caffeine uptake and degradation by plant association. Under our experimental conditions, the removal efficiency of the system was upper to 79%, indicating the capability of Populus-Brassica association to efficiently remove Zn, Cd, and CFN from mixed inorganic-organic-contaminated water in short term.

Water pollution is a severe worldwide problem that urgently requires development of novel sensing concepts allowing for monitoring in situ a variety of contaminants at very low concentrations in a costeffective and multiplexed format. Whispering Gallery Mode (WGM) resonators represent novel and promising tools for the development of high-performance sensing platforms for environmental monitoring. Here we report an overview of WGM platforms for monitoring different classes of water contaminants. The theoretical basis of these novel sensing platforms are presented. Several chemical/biochemical strategies for binding specific chemo/bio-receptors on the surface of the optical resonators are discussed. Finally, the main issues that currently hinder these devices from leaving research laboratories towards the development of high compact and sensitive tools to be launched on the market are reviewed and discussed together with future perspectives. (C) 2020 Elsevier B.V. All rights reserved.

Abiotic stresses, that characterize many world marginal areas, are increased by climate change. The plant response to these stresses consists of different processes to alleviate both cellular hyperosmolarity and ion disequilibrium or to synthesize antioxidant compounds. Cardoon (Cynara cardunculus L.) is a perennial crop of the Asteraceae family, native to the Mediterranean region, with a high production of biomass and grain, available for green chemistry, and able to grow in stressful environment. The aim of this work was to investigate different cardoon response mechanisms to abiotic stresses. Following this purpose, we evaluated the ability of cardoon seeds to germinate under salt stress condition and on the sprouts obtained we measured the total phenols content (TPC) and antioxidant activity (AA). In addition, the growth of cardoon seedlings under heavy metals (arsenic and cadmium) stress conditions was monitored. Moreover, based on library of cDNA previously constructed from seedlings growth in similar stress condition, the gene Phytochelatin Synthase (PS), associated with abiotic stress tolerance, was isolated. Furthermore, Natural Resistance of Macrophage (NRAMP3), Heavy metal ATPase (HMA), Inorganic Phosphate Transport (PHT), Zinc and Iron Protein (ZIP) genes associated with heavy metal stress were isolated and the levels of gene expression were measured. The results showed the ability of C. cardunculus to tolerate salt and heavy metals stresses, thanks to different defense mechanisms against abiotic stress implemented by cardoon plants. Then, this species can be considered as a promising future crop for green chemistry in marginal lands.

Freshwater crayfish are bioindicators of environmental pollution, often used for the assessment of heavy metal (HM) presence in the tissues, a time-consuming and expensive task. In this study, we propose the use of the vibrational spectroscopy to detect in a fast, non-destructive and sensitive way the presence of HM in the cephalothorax exoskeleton of the freshwater crayfish. Incorporation of HM into the cephalothorax exoskeleton was investigated under controlled laboratory conditions. In particular, the cephalothorax exoskeleton of five crayfish species (Astacus leptodactylus, Procambarus clarkii, Austropotamobius pallipes, Faxonius limosus, and Pacifastacus leniusculus) was analyzed by attenuated total reflection-Fourier transformed infrared (ATR-FTIR) spectroscopy in the presence or absence of cadmium (Cd), chromium (Cr), lead (Pb), nickel (Ni), and zinc (Zn) up to 4 weeks at various concentrations (0.01, 0.1, 1, 10, ppm). The ATR-FTIR profile of the crayfish cephalothorax exoskeleton was compatible with the presence of amorphous calcium carbonate, chitin, and proteins. The incubation with the HM revealed two main modifications: the shift of the peak from 859 to 872 cm(-1) and the appearance of a peak at 712 cm(-1). Both are ascribable to the HM interaction with calcium carbonate. The absorbance of both peaks increased along with the time of incubation, and the HM concentration. We conclude that ATR-FTIR analysis can be a useful, quick, and cost-sensitive tool to detect HM presence in the crayfish cephalothorax exoskeleton. However, it has to be regarded as a non-specific analytical technique for assessing HM contamination, since it is unable to discriminate between different HM.

A harbour sediment, previously remediated, was tested for soilless strawberry cultivation (Camarosa and Monterey cultivars), as an innovative, cost-effective and environment-friendly approach of sediment management. Sediments were tested as such (TS100) and mixed 1/1 (v/v) with a peat-based commercial substrate (TS50), using the peat-based medium as control (TS0). Substrates were characterized for some physicochemical properties (e.g. density, porosity and water capacity). Minerals (P, Ca, K, Na and Fe), heavy metals (Cu, Zn, Mn, Ni, Cr, Pb and Cd), aliphatic hydrocarbons (C> 12), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), dibenzodioxins and dibenzofurans were analysed in substrates and fruits. Sugars and organic acids, including the ascorbic, were also determined in fruits, as quality indicators. Notwithstanding remediation, sediments showed concentrations of Zn (206 mg kg(-1)), C> 12 (86 mg kg(-1)) and PAHs (47 mg kg(-1)) exceeding the limits established by the Italian L.D. 152/2006, regulating the contamination of soil in green areas, thus making its relocation in the environment not permitted as such. No evidence of fruit contamination by Cr, Pb and Cd was highlighted. Moreover, Cu, Zn and Ni fruit concentrations were comparable among treatments. Conversely, Mn showed statistically higher concentrations in TS0 fruits (56-57 mg kg(-1)) compared to those grown in sediment-based substrates (8-20 mg kg(-1)). Among organic contaminants, only dioxin-like PCBs were determined in fruits, at toxic equivalent concentrations fourfold lower than the limit established by the European Union. TS100 fruits showed a yield reduction from 40 to 70% for Camarosa and Monterey, but higher sugar and ascorbic acid contents. (C) 2019 Elsevier Ltd. All rights reserved.

This work discusses the results of a geochemical survey conducted in the Salerno urban area to determine the sources patterns of major, minor, trace and ultra-trace elements in soils. In particular, the study focused on elements that are potentially toxic and listed in the environmental Italian legislation (D.L. 152/06), in order to effectively monitoring an important aspect of environment health. A total of 151 topsoil samples were collected, air-dried and sieved (<2 mm). After aqua regia digestion the samples were analyzed for 42 elements by ICP-MS and ICP-AES. Geostatistical analyses were carried out in order to show the single element spatial distribution and the distribution of factor scores elemental associations from R-mode factor analysis. In performing factor analysis, the additive logratio (alr) transformation was applied to the whole dataset in order to deal with the closure effects of the investigated geochemical data, avoiding artefacts and spurious correlation. The use of alr-transformed data instead of the normal data in the factor analysis allowed for a better interpretation of the distribution patterns, since this produced four factor models which, once mapped, were easier to interpret. The study revealed that major and minor elements (Al, Ca, Fe, K, Mg, Na, P, S and Ti) have a perfectly natural distribution with no discernible association to any human activity or presence. In contrast, many trace and ultra-trace elements (Ag, As, Au, Ba, Be, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Pd, Pt, Rh, Sb, Sn, Tl, V and Zn) show anomalous concentration values located almost exclusively in highly inhabited areas, industrial sites and along high traffic roads. Other trace and ultra-trace elements (B, Bi, Ga, La, Sc, Se, Sr, Te, Th, Tl, U and W) show concentrations compatible with the natural background levels. Some potentially toxic elements (e.g. Pb and Zn) reach concentration levels tens of times higher than the legal limits in the busiest areas of the city. Exposure to high concentrations of these contaminants may cause health problems to people living in these zones.

Since time ago, membranes have greatly attracted the attention of researchers for different types of water-treatment applications, such as wastewater treatment, water purification, removal of microorganisms, chemical compounds, and heavy metals. Nowadays, one of the current challenges of research community definitely deals with the removal of toxic and heavy metals from water. In this regard, the current chapter provides enough inputs about the current advances and approaches of the use of membranes for such removal task, thereby addressing the highlighted literature survey of using polymeric and nanocomposite membranes for heavy-metal removal. Moreover, it gives up-to-date information related to those novel nanocomposite membranes and their contribution for water-treatment applications.

There is currently a large amount of research being done into the phytoremediation of polluted soils. Plant installation in contaminated soils may require the application of soil amendments, such as biochar, compost and/or iron grit, which can improve the soil conditions and reduce the metal (loid) phytoavailability and mobility. The beneficial effects of these amendments on soil properties, plant growth and metal (loid) accumulation ability have already been described, although their effect on the plants response machinery has been poorly studied. This study aimed to assess the effect of these amendments on Salix viminalis growth and metal (loid) accumulation, as well as elucidating associated molecular mechanisms. The results showed that the amendment applications improved plant growth by three fold, except for the biochar plus iron combination. It also revealed that metal (loid)s were not effectively translocated from the roots to the shoots (translocation factors <1), their bioaccumulation peaked in the roots, and increased in the presence of iron-based amendments. Corresponding proteomic profiles revealed 34 protein spots differentially represented and suggested that plants counteracted metal (loid)-induced oxidative stress after the addition of biochar and/or compost by eliciting proper defense and signaling pathways, and by redirecting the metabolic fluxes towards primary and secondary metabolism. However, they did highlight the occurrence of oxidative stress markers when the biochar plus iron amendment was applied, which could be both the cause and result of protein degradation impairment.

European policy is direct towards increasing the agricultural reuse of sludge on soil for improving the fertility; however, the effects of long-term pharmaceutical sewage sludge (PSS) application on soil properties are still unknown. Thus, the aim of this work was to evaluate the agronomic and environmental effects on soil after 17 years of organic amendment with PSS derived from daptomycin production. Five different doses of PSS were spread on lands located in Anagni, Central Italy. Physico-chemical soil properties were investigated, as well as total and bioavailable heavy metals, changes in the soil organic matter quality and biochemical functioning. PSS application showed a positive agronomic potential, improving SOM quality, increasing soil humified organic matter and raising plant nutrients. SOM dynamic was different at low and high PSS supplies, as confirmed by the chemical and biochemical analysis (e.g. C biomass, FDA hydrolysis activity, basal respiration, dehydrogenase, urease and phosphatase activities). However, in a long-term agricultural reuse, environmental risks of PSS recycling were related to the increase of some heavy metals (Hg, Zn and Cu) and exchangeable Na.

We present a novel constructed wetland called a vegetable depuration module (VDM) as a pilot test of a bioremediation system (BS) for decontaminating water and soil polluted with heavy metals. The VDM consisted of a pool filled with stones of different granulometry and a substrate top layer composed of a mixture of soil and volcanic ash (50:50, v/v) supplemented with 350 ppm Zn. The BS of sunflower plants colonized by the arbuscular mycorrhizal fungus Rhizophagus intraradices was planted in the VDM. Initially, the substrate registered high concentrations of Zn, Cr, Mn, Cu, and Sr, and had Eh > +500 mV and pH 8.4. Irrigation with a Cu solution by vertical flow was carried out. After 3 months, bioaccumulation factors ranged from 1.00 to 8.90, and translocation rates were >1 for Sr and Cu. Total metals extracted by the BS and percolation were 31%, 34%, 50%, 45%, and 57% for Zn, Cu, Mn, Cr, and Sr, respectively. Only the BS was capable of extracting 94% of Cu and 38% of Zn. VDM allowed us to calibrate the extractive performance of the studied elements in BS. This biotechnological development holds great potential for phytoremediation of polluted areas.

We present a novel constructed wetland called a vegetable depuration module (VDM) as a pilot test of a bioremediation system (BS) for decontaminating water and soil polluted with heavy metals. The VDM consisted of a pool filled with stones of different granulometry and a substrate top layer composed of a mixture of soil and volcanic ash (50:50, v/v) supplemented with 350 ppm Zn. The BS of sunflower plants colonized by the arbuscular mycorrhizal fungus Rhizophagus intraradices was planted in the VDM. Initially, the substrate registered high concentrations of Zn, Cr, Mn, Cu, and Sr, and had Eh > +500 mV and pH 8.4. Irrigation with a Cu solution by vertical flow was carried out. After 3 months, bioaccumulation factors ranged from 1.00 to 8.90, and translocation rates were >1 for Sr and Cu. Total metals extracted by the BS and percolation were 31%, 34%, 50%, 45%, and 57% for Zn, Cu, Mn, Cr, and Sr, respectively. Only the BS was capable of extracting 94% of Cu and 38% of Zn. VDM allowed us to calibrate the extractive performance of the studied elements in BS. This biotechnological development holds great potential for phytoremediation of polluted areas.