Reuse of polymeric waste for the treatment of marine water polluted by diesel.

Accidental diesel spills can occur in marine environments such as harbors, leading to adverse effects on the environmental compartment and humans. This study proposes the surgical mask as an affordable and sustainable adsorbent for the remediation of diesel-contaminated seawater to cope with the polymeric waste generated monthly in hospital facilities. This approach can also be helpful considering a possible future pandemic, alleviating the pressure on the waste management system by avoiding improper mask incineration and landfilling, as instead occurred during the previous COVID-19. Batch adsorption-desorption experiments revealed a complete diesel removal from seawater after 120 min with the intact laceless mask, which showed an adsorption capacity of up to 3.43 g/g. The adsorption curve was better predicted via Weber and Morris's kinetic (R2 = 0.876) and, in general, with Temkin isotherm (R2 = 0.965-0.996) probably due to the occurrence of chemisorption with intraparticle diffusion as one of the rates-determining steps. A hysteresis index of 0.23-0.36 was obtained from the desorption isotherms, suggesting that diesel adsorption onto surgical masks was faster than the desorption mechanism. Also, the effect of pH, ionic strength and temperature on diesel adsorption was examined. The results from the reusability tests indicated that the surgical mask can be regenerated for 5 consecutive cycles while decreasing the adsorption capacity by only approximately 11%.

Assessment of environmental parameters effect on potentially toxic elements mobility in foreshore sediments to support marine-coastal contamination prediction.

Potentially toxic elements (PTEs) presence in marine sediments can significantly affect the environmental quality and negatively influence economy and recreational activities in related areas. Accordingly, contamination monitoring and control in the marine environment is a fundamental task. In this work, four PTEs behavior (i.e. As, Hg, Pb, and Zn) in sandy foreshore sediments (SFSs) was thoroughly investigated at different pH, redox potential and temperature conditions of the marine water. For all the tests, the released As was 2.7-6 times higher than its initial concentration in water. Nonetheless, final mass balances showed that preferential release in the liquid phase occurred for Pb and Hg (up to 10 % and 9.1 %, respectively). Moreover, final Zn and Hg content increase in SFSs labile fractions indicated their higher bioavailability after the tests. The obtained results outline an approach useful to predict the contaminants behavior in marine matrices and support environmental monitoring and preservation strategies.

Phenanthrene removal from a spent sediment washing solution in a continuous-flow stirred-tank reactor.

The issue of polycyclic aromatic hydrocarbons (PAHs) is widespread in marine sediments involving ecological systems and human health. Sediment washing (SW) has proven to be the most effective remediation approach for sediments polluted by PAHs, such as phenanthrene (PHE). However, SW still raises waste handling concerns due to a considerable amount of effluents generated downstream. In this context, the biological treatment of a PHE- and ethanol-containing spent SW solution can represent a highly efficient and environmentally-friendly strategy, but its knowledge is still scarce in scientific literature and no studies have so far been conducted in continuous mode. Therefore, a synthetic PHE-polluted SW solution was biologically treated in a 1 L aerated continuous-flow stirred-tank reactor for 129 days by evaluating the effect of different pH values, aeration flowrates and hydraulic retention times as operating parameters over five successive phases. A PHE removal efficiency of up to 75-94% was achieved by an acclimated PHE-degrading consortium mainly composed of Proteobacteria, Bacteroidota and Firmicutes phyla through biodegradation following the adsorption mechanism. PHE biodegradation, mainly occurring via the benzoate route due to the presence of PAH-related-degrading functional genes and a phthalate accumulation up to 46 mg/L, was also accompanied by a reduction of dissolved organic carbon and ammonia nitrogen above 99% in the treated SW solution.

Soil science and environmental research.

As indicated in the call for papers posted for this Special Issue, Soil Science deals with various environmental compartments, so it is closely related to Environmental Research. It is clear that synergisms and collaboration are keys to reach the most fruitful relations among different sciences and scientists, and especially in all that focused on the Environment. In this line, considering Soil Science, Environmental Research, and the multiple and complex eventual combinations involving them, could give new highly interesting works focused on any of the specific subjects covered, as well as on relations among these sciences. The main objective should be going further in positive interactions that could help in protecting the Environment, proposing solutions to face hazards that are drastically threatening our planet. In view of that, the Editors of this Special Issue invited researchers to submit high-quality manuscripts including new experimental data, as well as scientifically founded discussion and reflections on the matter. The VSI has received 171 submissions, with 27% of them being accepted after peer-review. The Editors think that the papers included in this VSI have high scientific value and provide scientific knowledge on the field. In this editorial piece the Editors include comments and reflections on the papers published in the SI.

A novel green approach for silver recovery from chloride leaching solutions through photodeposition on zinc oxide.

Silver is extensively used in electronics, industrial catalysis, and biomedical sector owing to its enhanced physicochemical properties. E-waste recycling may contribute significantly to enhance silver recovery in the view of a circular economy and limit the depletion of mineral sources. In this scenario, hydrometallurgical routes represent the most widely used techniques for silver extraction/recovery and require strong acidic solutions, high temperatures, and multiple operating units. An alternative sustainable route for silver recovery from leaching solutions used for silver extraction in industrial applications is herein proposed for the first time. The novel green process of silver recovery is based on the UV/vis light-driven photocatalytic deposition of pure metallic silver over low-cost and non-toxic ZnO photocatalyst. In the second step, ZnO is dissolved by slight acidification and pure metallic silver is easily recovered. Low environmental impact, mild operating conditions, and economic viability are among the major perks of the new silver recovery process developed. In the view of a full-scale implementation, several operating conditions of the recovery process (i.e., photocatalyst load, starting silver concentration, type of hole scavenger and irradiation) were thoroughly investigated. A mathematical model capable of describing the system behaviour under different operating conditions was also developed and allowed to estimate unknown kinetic parameters for the Ag-photodeposition process.

Editorial on the Topic "New Research on Detection and Removal of Emerging Pollutants".

With the Topic "New Research on Detection and Removal of Emerging Pollutants" (https://www [...].

The microbial world in copper sulfide flotation plants (CSFP): Novel insights into bacterial communities and their application as potential pyrite bioreagents.

Operations in copper sulfide flotation plants (CSFP) are complex and governed by several variables such as available technologies, reagents, and environmental conditions. However, few investigations are related to studying the microbial communities. These aspects provide a reason to compare the bacterial communities of two CSFP operated with freshwater (FwFlo) and seawater (SwFlo), and study whether indigenous bacteria could be used as pyrite bioreagents. Analyses were determined through next-generation sequencing by Illumina MiSeq System and conducted throughout the entire process: (i) minerals before and after grinding; (ii) final concentrate and concentrate thickener overflow; (iii) final tailings and tailings thickener overflow; and (iv) intake water. Bacterial strains from both plants were tested as potential bioreagents, given their tendency to adhere to pyrite after 5 min. In both CSFP, Proteobacteria (relative abundance from 45.48% to 79.22%), followed by Bacteroidetes (9.37%-44.7%), were the most abundant phyla. Regarding species, Algoriphagus olei (11.35%-43.52%) was present exclusively in FwFlo samples in contact with process water and absent in the mineral before grinding, where Cupriavidus metallidurans (16.05%) and Pseudomonas_uc (11.79%) predominated. In SwFlo samples, Marinobacter flavimaris (3.47%-41.1%), and GU061212-s (10.92%-27.63%), were the most abundant microorganisms. All of them were also detected in intake seawater. The strains with the highest adhesion rate (from 29.84% ± 0.14-100%) were phylogenetically identified as species of the genera Marinobacter, Pseudomonas, Idiomarina, Halomonas, Bacillus, Aerocuccus, and Peribacillus. Our results reveal that bacterial communities are critically dependent on process waters during mining activities, and our data depicted that indigenous bacteria could be used as potential pyrite bioreagents, evidenced by a high adhesion rate. It is thus possible to propose that different indigenous bacterial strains could be considered as new bioreagents to reduce the impact of conventional flotation reagents on health from an environment friendly perspective.

Removal of emerging pollutants from the environment: From bioadsorbents to nanoparticle-based systems.

In the Call for Papers corresponding to this Virtual Special Issue (VSI), the Editors indicated that, as is well known, emerging pollutants include a variety of substances that pose remarkable risks for the environment and public health. In fact, emerging pollutants are considered a matter of concern deserving increasing efforts to elucidate their occurrence, fate, repercussions, and alternatives to their removal from the various environmental compartments where they can be found after spreading as contaminants. Also, the Editors commented that, among the various alternatives that can be considered for achieving their successful removal, some of them are based on the use of sorbent materials, and, specifically, bioadsorbents, which are attractive due to the efficacy and low cost associated with some of them. Another alternative is related to the utilization of nanoparticle-based systems, which may be considered a promising field of research in this way. In both cases, obtaining new research results, as well as designing and programming new ways of going steps ahead in the investigation of both kinds of materials, would be key objectives. According to the previous considerations, the Editors of the VSI invited researchers having new data concerning these aspects to submit manuscripts with experimental results, discussion, reflections and prospective related to their work. With the Special Issue closed, the number of submissions received was 83, with 40 high-quality works being accepted for publication, increasing the overall knowledge on this topic by providing results that we are sure will be of value for the scientific community and the society.

Exploring the effect on the environment of encapsulated micro- and nano-plastics into asphalt mastics for road pavement.

A new environmental problem is represented by the huge transformation of plastic waste released into the environment into small fragments, the so called micro- and nano-plastics, due to atmospheric phenomena. The smaller the size of the plastic fragments, the more their spreading into environmental compartments. The aim of this study is to test encapsulation into asphalt mastics of waste plastic material (WPM) as sustainable strategy to obtain road flexible pavements and to evaluate the potential release in water of micro and nano plastics. A new mastic mixing method was developed to blend the WPM with the bitumen contained into a bitumen emulsion (BE60/40) by adopting low mixing temperatures. Three different WPM contents, equal to 5, 10 and 20% by the weight of the bitumen contained in the BE60/40, were adopted to produce the mastics; the mastics' rheological properties, obtained by frequency sweep and multiple stress creep and recovery tests, were compared to those of a traditional asphalt mastic containing limestone filler. The aging of asphalt mastics was analyzed by soaking them in water and gradually lowering and raising temperature between -10 and 60 °C at predefined intervals. The addition of WPM improved greatly the asphalt mastic performance; in particular, for a WPM content of 10%, the rheological response in terms of stiffness remained unchanged after the mastic underwent thermal excursions in water. Encapsulation of micro and nano plastics into mastics reduced of more than 99% their potential water release.

Characterising contaminants distribution in marine-coastal sediments through multivariate and nonparametric statistical analyses: a complementary strategy supporting environmental monitoring and control.

This work investigates a statistical approach analysing data from monitoring activities on marine-coastal areas for environmental quality determination and surveillance. Analyses were performed on a database of the Environmental Protection and Prevention Agency of the Puglia Region. As, Cr, Ni, and Pb concentration values in marine sediments and biota from 2013 to 2015 and 2017 were processed to investigate different contaminant characteristics. Hierarchical cluster analysis identified three contaminant distribution classes with (1) highest Cr, Ni, and Pb concentrations, (2) highest As concentration, and (3) lowest contaminants concentration. The Kruskal-Wallis and Friedman tests showed that contaminant distributions were statistically different when considering the monitoring years and classes. However, statistical similarities resulted during the 2013-2017 and 2014-2015 periods. Spearman's coefficients displayed positive correlations among the pollutants in each matrix and mainly negative correlations for matrices comparison. This methodology aims to provide a practical support for monitoring to identify potential environmental deterioration over time and correlations with specific contamination sources.

Galdieria sulphuraria ACUF427 Freeze-Dried Biomass as Novel Biosorbent for Rare Earth Elements.

Rare earth elements (REEs) are essential components of modern technologies and are often challenging to acquire from natural resources. The demand for REEs is so high that there is a clear need to develop efficient and environmentally-friendly recycling methods. In the present study, freeze-dried cells of the extremophile Galdieria sulphuraria were employed to recover yttrium, cerium, europium, and terbium from quaternary-metal aqueous solutions. The biosorption capacity of G. sulphuraria freeze-dried algal biomass was tested at different pHs, contact times, and biosorbent dosages. All rare earths were biosorbed in a more efficient way by the lowest dose of biosorbent, at pH 4.5, within 30 min; the highest removal rate of cerium was recorded at acidic pH (2.5) and after a longer contact time, i.e., 360 min. This study confirms the potential of freeze-dried cells of G. sulphuraria as innovative ecological biosorbents in technological applications for sustainable recycling of metals from e-waste and wastewater.

Role of organic nanoparticles on transport and fate of various dyes in aqueous solution.

This work studies the interaction of organic nanoparticles (ON) with various dyes in aqueous solution, to elucidate the role of ON on transport and fate of dyes in the environment, and on dyes removal from wastewater. Studied dyes are Acid Red 66 (AR66), Methylene Blue (MB), Reactive Black 5 (RB5), and Reactive Violet 5 (RV5). ON are extracted from organic matter of anthropogenic origin through resuspension of its colloidal fraction, and successive filtration and dialysis of the obtained suspension. Mechanisms of interaction are investigated initially through three-dimensional excitation emission matrix (3DEEM) analysis. Obtained data indicate that dynamic interactions occur strongly between dye molecules and ON aggregates. 3DEEM spectra of mixed samples containing ON together with one of the tested dyes, present a shape similar to the one of ON alone, but each of them is characterized by specific differences in terms of peaks quenching and shift. The analysis of these singularities suggests that dye molecules are bound to the functional groups of ON through H-bonds, according to the following steps: i) dyes reach the surface of ON aggregates; ii) the molecules pass through the hydrophilic surface of ON aggregates, and reach their hydrophobic core; iii) the dyes are sequestrated into the hydrophobic core of ON aggregates. Nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) spectroscopies analysis confirm the formation of supramolecular aggregates with stable micellar hydrophobic structure, mainly consisting of aliphatic fractions of ON, which explain the disappearance of aromatic groups signals from dyes.

Coupling of desorption of phenanthrene from marine sediments and biodegradation of the sediment washing solution in a novel biochar immobilized-cell reactor.

The recurrent dredging of marine sediments needs the use of ex-situ technologies such as sediment washing (SW) to effectively remove polycyclic aromatic hydrocarbons. Notwithstanding, the large volumes of generated spent SW effluents require adequate treatment by employing highly-efficient, inexpensive and environmentally-friendly solutions. This study proposes the phenanthrene (PHE) desorption from sediments using Tween® 80 (TW80) as extracting agent and the treatment of the resulting spent SW solution in a biochar (BC) immobilized-cell bioreactor. The SW process reached the highest PHE removal of about 91% using a surfactant solution containing 10,800 mg L-1 of TW80. The generated amount of spent PHE-polluted SW solution can be controlled by keeping a solid to liquid ratio of 1:4. A PHE degradation of up to 96% was subsequently achieved after 43 days of continuous reactor operation, aerobically treating the TW80 solution in the BC immobilized-cell bioreactor with a hydraulic retention time of 3.5 days. Brevundimonas, Chryseobacterium, Dysgonomonas, Nubsella, and both uncultured Weeksellaceae and Xanthobacteraceae genera were mainly involved in PHE biodegradation. A rough economic study showed a total cost of 342.60 € ton-1 of sediment, including the SW operations, TW80 and BC supply and the biological treatment of the SW solution.

New trends on green energy and environmental technologies, with special focus on biomass valorization, water and waste recycling: editorial of the special issue.

In this editorial piece, the Editors of the Virtual Special Issue (VSI) "New Trends on Green Energy and Environmental Technologies, with Special Focus on Biomass Valorization, Water and Waste Recycling", present summarized data corresponding to the accepted submissions, as well as additional comments regarding the thematic of the VSI. Overall, 83 manuscripts were received, with final publication of those having the highest quality, accepted after peer-reviewing. The Editors think that the result is a set of very interesting papers that increase the knowledge on the matter, and which would be useful for researchers and the whole society.

Bioremoval of Yttrium (III), Cerium (III), Europium (III), and Terbium (III) from Single and Quaternary Aqueous Solutions Using the Extremophile Galdieria sulphuraria (Galdieriaceae, Rhodophyta).

The lanthanides are among the rare earth elements (REEs), which are indispensable constituents of modern technologies and are often challenging to acquire from natural resources. The demand for REEs is so high that there is a clear need to develop efficient and environmentally-friendly recycling methods. In the present study, living cells of the extremophile Galdieria sulphuraria were used to remove four REEs, Yttrium, Cerium, Europium, and Terbium, from single- and quaternary-metal aqueous solutions. Two different strains, SAG 107.79 and ACUF 427, were exposed to solutions buffered at pH 2.5, 3.5, 4.5, and 5.5. Our data demonstrated that the removal performances were strain and pH dependent for all metal ions. At lower pH, ACUF 427 outperformed SAG 107.79 considerably. By increasing the pH of the solutions, there was a significant surge in the aqueous removal performance of both strains. The same trend was highlighted using quaternary-metal solutions, even if the quantities of metal removed were significantly lower. The present study provided the first insight into the comparative removal capacity of the Galdieria sulphuraria strains. The choice of the appropriate operational conditions such as the pH of the metal solutions is an essential step in developing efficient, rapid, and straightforward biological methods for recycling REEs.

Phytoremediation of a pyrene-contaminated soil by Cannabis sativa L. at different initial pyrene concentrations.

This study proposes the phytoremediation of a pyrene (PYR)-contaminated soil by Cannabis sativa L. The experimental campaign was conducted along a 60 days period using three different initial PYR concentrations (i.e., 50, 100 and 150 mg kg TS-1 of soil) in 300 mL volume pots under greenhouse conditions (18-25 °C and 45-55% humidity). After 60 days of hemp growth and flourishing, the highest PYR removal reached approximately 95% in planted soil, 35% higher than in the unplanted control. PYR accumulation was observed in both roots and aerial parts of the plant, with a higher PYR uptake at increasing initial PYR concentrations in soil. The initial PYR concentration affected the growth and, thus, the phytoremediation potential of C. sativa L., which was the result of different removal mechanisms. Overall, the lowest initial PYR concentration was the one that resulted in the highest PYR removal. The interaction between the plant roots and microorganisms in rhizosphere was likely associated with PYR removal in this study. The highest DHO activity of 66.26 µg INTF g-1 TS-1 was observed in the soil spiked with 50 mg PYR·kg TS-1.

Phosphorous removal and recovery from urban wastewater: Current practices and new directions.

Phosphate rocks are an irreplaceable resource to produce fertilizers, but their availability will not be enough to meet the increasing demands of agriculture for food production. At the same time, the accumulation of phosphorous discharged by municipal wastewater treatment plants (WWTPs) is one of the main causes of eutrophication. In a perspective of circular economy, WWTPs play a key role in phosphorous management. Indeed, phosphorus removal and recovery from WWTPs can both reduce the occurrence of eutrophication and contribute to meeting the demand for phosphorus-based fertilizers. Phosphorous removal and recovery are interconnected phases in WWTP with the former generally involved in the mainstream treatment, while the latter on the side streams. Indeed, by reducing phosphorus concentration in the WWTP side streams, a further improvement of the overall phosphorus removal from the WWTP influent can be obtained. Many studies and patents have been recently focused on treatments and processes aimed at the removal and recovery of phosphorous from wastewater and sewage sludge. Notably, new advances on biological and material sciences are constantly put at the service of conventional or unconventional wastewater treatments to increase the phosphorous removal efficiency and/or reduce the treatment costs. Similarly, many studies have been devoted to the development of processes aimed at the recovery of phosphorus from wastewaters and sludge to produce fertilizers, and a wide range of recovery percentages is reported as a function of the different technologies applied (from 10-25% up to 70-90% of the phosphorous in the WWTP influent). In view of forthcoming and inevitable regulations on phosphorous removal and recovery from WWTP streams, this review summarizes the main recent advances in this field to provide the scientific and technical community with an updated and useful tool for choosing the best strategy to adopt during the design or upgrading of WWTPs.

Feasibility of growing Salicornia species in a coastal environment through planting date and density management in a direct seawater irrigation system.

Two field experiments were conducted to evaluate six Salicornia species (Salicornia bigelovii Torr., S. europaea L., S. persica Gorgan ecotype, S. persica Urmia ecotype, S. sinus persica Bushehr ecotype, and S. persica Central Plateau ecotype) at different planting dates and densities under irrigation with Persian Gulf water. Evaluated planting dates were 14 November and 18 December 2016 and 16 January, 8 February, 8 March, and 28 March 2017. Examined planting densities included 13, 20, and 40 plant m-2. Only S. bigelovii and S. europaea produced measurable yield in all planting dates. The highest dry weight (651.1 gm-2) was obtained in S. sinus persica (Bu) planted on 8 February. Dry weight of S. bigelovii, S. europaea, S. sinus persica Bushehr, S. persica Central Plateau, S. persica Gorgan, and S. persica Urmia planted on 8 March were 174.2, 220.7, 542.5, 240.9, 158.0, and 147.5 g m-2, respectively. The ash contents of S. bigelovii, S. europaea, S. sinus persica Bushehr, S. persica Central Plateau, S. persica Gorgan, and S. persica Urmia were 46.3%, 45.0%, 49.6%, 49.6%, 50.0%, and 53.1%, respectively. Sodium and chloride contents of different Salicornia species varied from 13-15% and 16-17%, respectively. The oilseed content of S. bigelovii and S. sinus persica Bushehr was about 24.0% for both species. The highest and lowest dry weight, from the second experiment, were for S. sinus persica Bushehr and S. persica Central Plateau, respectively, in all planting density. The highest dry weight equal to 1336.2 gm-2 was obtained for S. sinus persica Bushehr in 40 plant m-2 density. Under such conditions, forage production potential of Salicornia is more achievable rather than seed production. Nevertheless, high ash content is a serious constraint to direct consumption by livestock; therefore, determining the nutritional value of Salicornia fodder requires further evaluations.

Salicylic Acid Manipulates Ion Accumulation and Distribution in Favor of Salinity Tolerance in Chenopodium quinoa.

Although the effects of salicylic acid (SA) on increasing plant growth in saline conditions have been well known, the mechanisms of induction of salinity tolerance, especially in quinoa (Chenopodium quinoa Willd.), are not fully understood. In the present work, two quinoa genotypes (Titicaca and Giza1) were treated with different SA concentrations (0, 0.75, and 1.5 mM) under varied irrigation water salinities (0, 7, 14, and 21 dS m-1). Salinity decreased shoot and root growth, potassium (K+) concentration, and potassium to sodium ratio (K/Na) and increased sodium (Na+) and chlorine (Cl-) concentrations in both cultivars. Calcium (Ca2+) and magnesium (Mg2+) concentrations increased in 7 dS m-1 but decreased in higher salinities. The growth and salinity tolerance of Giza1 were higher, while the growth of Giza1 increased and of Titicaca decreased in high salinity. Salicylic acid at 0.75-mM concentration increased shoot and root growth and improved the ions concentration in favor of the plant, while the 1.5-mM concentration either had no significant effect or had a negative impact. The ions distribution estimated by K/Na selectivity and storage factor (SF) indicated quinoa accumulated more ions in roots under saline conditions. Salicylic acid increased NaSF, ClSF, and MgSF and decreased KSF and CaSF, meaning less Na+, Cl-, and Mg2+ and more K+ and Ca2+ transferred to shoots in SA-treated plants. Importantly, Giza1, as the more tolerant cultivar, had higher NaSF and ClSF and lower KSF, CaSF, and MgSF. In general, the concentrations of ions in roots were higher than in shoots. The results indicated more ions accumulation in the root could be one of the most important mechanisms of salinity tolerance in quinoa, and the more tolerant cultivar (Giza1) transferred less Na+ and Cl- and more K+ and Ca2+ and Mg2+ to the shoot.

A nonlinear autoregressive exogenous (NARX) model to predict nitrate concentration in rivers.

Forecasting nitrate concentration in rivers is essential for environmental protection and careful treatment of drinking water. This study shows that nonlinear autoregressive with exogenous inputs neural networks can provide accurate models to predict nitrate plus nitrite concentrations in waterways. The Susquehanna River and the Raccoon River, USA, were chosen as case studies. Water discharge, water temperature, dissolved oxygen, and specific conductance were considered exogenous inputs. The forecasting sensitivity to changes in the exogenous input parameters and time series length was also assessed. For Kreutz Creek at Strickler station (Pennsylvania), the prediction accuracy increased with the number of exogenous input variables, with the best performance achieved considering all the variables (R2 = 0.77). The predictions were accurate also for the Raccoon River (Iowa), although only the water discharge was considered exogenous input (South Raccoon River at Redfield-R2 = 0.94). Both short- and long-term predictions were satisfactory.