Microplastic in an apex predator: evidence from Barn owl (Tyto alba) pellets in two sites with different levels of anthropization

Plastic pollution in terrestrial and freshwater environments and its accumulation along food chains has been poorly studied in birds. The Barn owl (Tyto alba) is an opportunistic and nocturnal apex predator feeding mostly on small mammals. In this note, we reported evidence of microplastics (MPs) contamination in Barn owl pellets collected, for the first time, in two sites with different levels of anthropization (low: natural landscape mosaic vs. high extensive croplands). The following polymers have been recorded: polyvinylchloride (PVC), polyethylene (PE), expanded polyester (EPS), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyester (PL), viscose, and starch-based biopolymer. We found significant higher MPs frequency in the most anthropized site. Our results suggest that pellet' analysis may represent a cost-effective method for monitoring MP contamination along food chains in terrestrial ecosystems.

Fate of the biofilm chips overflowed from a wastewater treatment plant

In February 2018 over 100 millions of polyethylene biofilm chips overflowed from a wastewater treatment plant located at Capaccio Paestum (Italy) and due to the Thyrrhenian Sea currents, in few days they invaded the coasts of Campania, Lazio and Tuscany. During the following months the diffusion involves all the coasts of the western Mediterranean, including Spain, France and Tunisia. Samples of chips were recovered mainly along the Latium coasts (Italy) during the last 6 years. Following the exposure of the biofilm chips to the environmental conditions, the effect of natural weathering on polyethylene have been studied. The following annual decreases were evaluated: thickness 9.5 μm, diameter 18.5 μm and weight 3.7 mg while the average value of the size of all recovered items (n = 60) are: thickness = 2.936 ± 0.0406 mm, diameter = 44.349 ± 0.1266 mm and weight = 1.1593 ± 0.0248 g. Considering the weight loss, it was calculated that the complete mineralization of the disks will occur in 310 years producing about 0.5 tons of microplastics per year. FTIR analysis was used to investigate the change of chemical structure of the polyethylene. The Carbonyl index (CI), Vinyl index (VI) and Hydroxyl normalized absorbance peak were used to evaluate the polymer degradation while Scanning Electron Microscopy (SEM) was used to characterize the surface of the polymer samples. It was observed that erosion/degradation increases with time spent in the environment, above all from the last two years. The static contact angle was always >90° confirming that the surface of the biofilm chip is hydrophilic. The Oxygen/Carbon ratio increase with time: 0.18 and 0.27 has been found for 2018 and 2023 disks respectively confirming the progressive oxidative process. From TGA analysis a slightly reduction of decomposition temperature has been evaluated.

Microbial colonization patterns and biodegradation of petrochemical and biodegradable plastics in lake waters: insights from a field experiment

Introduction

Once dispersed in water, plastic materials become promptly colonized by biofilm-forming microorganisms, commonly known as plastisphere.

Methods

By combining DNA sequencing and Confocal Laser Scanning Microscopy (CLSM), we investigated the plastisphere colonization patterns following exposure to natural lake waters (up to 77 days) of either petrochemical or biodegradable plastic materials (low density polyethylene - LDPE, polyethylene terephthalate - PET, polylactic acid - PLA, and the starch-based MaterBi® - Mb) in comparison to planktonic community composition. Chemical composition, water wettability, and morphology of plastic surfaces were evaluated, through Transform Infrared Spectroscopy (ATR-FTIR), Scanning Electron Microscopy (SEM), and static contact angle analysis, to assess the possible effects of microbial colonization and biodegradation activity.

Results and Discussion

The phylogenetic composition of plastisphere and planktonic communities was notably different. Pioneering microbial colonisers, likely selected from lake waters, were found associated with all plastic materials, along with a core of more than 30 abundant bacterial families associated with all polymers. The different plastic materials, either derived from petrochemical hydrocarbons (i.e., LDPE and PET) or biodegradable (PLA and Mb), were used by opportunistic aquatic microorganisms as adhesion surfaces rather than carbon sources. The Mb-associated microorganisms (i.e. mostly members of the family Burkholderiaceae) were likely able to degrade the starch residues on the polymer surfaces, although the Mb matrix maintained its original chemical structure and morphology. Overall, our findings provide insights into the complex interactions between aquatic microorganisms and plastic materials found in lake waters, highlighting the importance of understanding the plastisphere dynamics to better manage the fate of plastic debris in the environment.

Design of a 3D Amino-Functionalized Rice Husk Ash Nano-Silica/Chitosan/Alginate Composite as Support for Laccase Immobilization

Recycling of agro-industrial waste is one of the major issues addressed in recent years aimed at obtaining products with high added value as a future alternative to traditional ones in the per-spective of a bio-based and circular economy. One of the most produced wastes is rice husk and it is particularly interesting because it is very rich in silica, a material with a high intrinsic value. In the present study, a method to extract silica from rice husk ash (RHA) and to use it as a carrier for the immobilization of laccase from Trametes versicolor was developed. The obtained mesoporous nano-silica was characterized by X-ray diffraction (XRD), ATR-FTIR spectroscopy, Scanning Elec-tron Microscopy (SEM), and Energy Dispersive X-ray spectroscopy (EDS). A nano-silica purity of about 100% was found. Nano-silica was then introduced in a cross-linked chitosan/alginate scaffold to make it more easily recoverable after reuse. To favor laccase immobilization into the composite scaffold, functionalization of the nano-silica with (γ-aminopropyl) triethoxysilane (APTES) was performed. The APTES/RHA nano-silica/chitosan/alginate (ARCA) composite al-lowed to obtain under mild conditions (pH 7, room temperature, 1.5 h reaction time) a robust and easily reusable solid biocatalyst with 3.8 U/g of immobilized enzyme which maintained 50% of its activity after six reuses. The biocatalytic system, tested for syringic acid bioremediation, was able to totally oxidize the contaminant in 24 h.

Plastisphere in lake waters: Microbial diversity, biofilm structure, and potential implications for freshwater ecosystems

Once dispersed in water, microplastic (MP) particles are rapidly colonised by aquatic microbes, which can adhere and grow onto solid surfaces in the form of biofilms. This study provides new insights on microbial diversity and biofilm structure of plastisphere in lake waters. By combining Fourier Confocal Laser Scanning Microscopy (CLSM), Transform Infrared Spectroscopy (FT-IR) and high-throughput DNA sequencing, we investigated the microbial colonization patterns on floating MPs and, for the first time, the occurrence of eukaryotic core members and their possible relations with biofilm-forming bacterial taxa within the plastisphere of four different lakes. Through PCR-based methods (qPCR, LAMP-PCR), we also evaluated the role of lake plastisphere as long-term dispersal vectors of potentially harmful organisms (including pathogens) and antibiotic resistance genes (ARGs) in freshwater ecosystems. Consistent variation patterns of the microbial community composition occurred between water and among the plastisphere samples of the different lakes. The eukaryotic core microbiome was mainly composed by typical freshwater biofilm colonizers, such as diatoms (Pennales, Bacillariophyceaea) and green algae (Chlorophyceae), which interact with eukaryotic and prokaryotic microbes of different trophic levels. Results also showed that MPs are suitable vectors of biofilm-forming opportunistic pathogens and a hotspot for horizontal gene transfer, likely facilitating antibiotic resistance spread in the environments.

Anthropogenic particles in coypu (Myocastor coypus; Mammalia, Rodentia)' faeces: first evidence and considerations about their use as track for detecting microplastic pollution

Anthropogenic plastic litter is widespread in all environments, with particular emphasis on aquatic habitats. Specifically, although freshwater mammals are important as they are at the top of food web, research mainly focus on marine animals, while only few studies have been carried out on freshwater mammals. The main gap is that microplastics (MP) are completely understudied in freshwater mammals. Here, we reported the first evidence of the presence of anthropogenic particles (including MP) in coypu (Myocastor coypus)' faeces. Coypu is a rodent mammal inhabiting rivers and wetland areas, and we discussed our preliminary data suggesting the use of these tracks as possible future bioindicator of MP pollution in wetlands and freshwaters. We collected 30 coypu's faeces in "Torre Flavia wetland" nature reserve. Then, in laboratory, faeces were digested in 30 ml hydrogen peroxide (30%) for a week a 20 °C and analysed under stereoscope. All the suspected found MP were isolated in a petri dish, using FT-IR analysis to confirm the polymers. Overall, we recorded 444 natural and anthropogenic particles with most of items being fibres. FT-IR analysis of the 10% of the particles recovered revealed that 72% of them was not MP (mainly, polyethylene, polyethylene terephthalate, and polyamide). Also, the number of anthropogenic particles is not correlated with the faecal weight. Given that alien species, such as coypu, are widespread species, our results might have a great importance as these species and MP in faecal tracks may be used as undirect proxy of environmental bioavailability of MP pollution.

Microplastic pollution in perch (Perca fluviatilis, Linnaeus 1758) from Italian south-alpine lakes

Microplastic particles (MPs) contamination of aquatic environments has raised a growing concern in recent decades because of their numerous potential toxicological effects. Although fish are among the most studied aquatic organisms, reports on MPs ingestion in freshwater environments are still scarce. Thus, there is still much to study to understand the uptake mechanisms, their potential accumulation among the food webs and their ecotoxicological effects. Here, MPs presence in the digestive system of one of the most widespread and commercially exploited freshwater fish, the perch (Perca fluviatilis, Linnaeus 1758), was investigated in four different south-alpine lakes, to assess the extent of ingestion and evaluate its relation to the body health condition. A total of 80 perch specimen have been sampled from the Italian lakes Como, Garda, Maggiore and Orta. Microplastic particles occurred in 86% of the analysed specimens, with average values ranging from 1.24 ± 1.04 MPs fish^-1 in L. Como to 5.59 ± 2.61 MPs fish^-1 in L. Garda. The isolated particles were mainly fragments, except in L. Como where films were more abundant. The most common polymers were polyethylene, polyethylene terephthalate, polyamide, and polycarbonate, although a high degree of degradation was found in 43% of synthetic particles, not allowing their recognition up to a single polymer. Despite the high number of ingested MPs, fish health (evaluated by means of Fulton's body condition and hepatosomatic index) was not affected. Instead, fullness index showed an inverse linear relationship with the number of ingested particles, which suggests that also in perch MPs presence could interfere with feeding activity, as already described for other taxa.

Diversity and predicted inter- and intra-domain interactions in the Mediterranean Plastisphere

This study investigated the biogeography, the presence and diversity of potentially harmful taxa harbored, and potential interactions between and within bacterial and eukaryotic domains of life on plastic debris in the Mediterranean. Using a combination of high-throughput DNA sequencing (HTS), Causal Network Analysis, and Scanning Electron Microscopy (SEM), we show regional differences and gradients in the Mediterranean microbial communities associated with marine litter, positive causal effects between microbes including between and within domains of life, and how these might impact the marine ecosystems surrounding them. Adjacent seas within the Mediterranean region showed a gradient in the microbial communities on plastic with non-overlapping endpoints (Adriatic and Ligurian Seas). The largest predicted inter-domain effects included positive effects of a novel red-algal Plastisphere member on its potential microbiome community. Freshwater and marine samples housed a diversity of fungi including some related to disease-causing microbes. Algal species related to those responsible for Harmful Blooms (HABs) were also observed on plastic pieces including members of genera not previously reported on Plastic Marine Debris (PMD).

Litter impacts on marine birds: The Mediterranean Northern gannet as case study

Litter are ubiquitous and increasing in the coastal and marine environments. Entanglement with litter is one of the principal causes of mortality in seabirds, but the population-level consequences are unknown. Currently, all seabirds collect litter for nesting material. Northern Gannets are not the exception and there are several cases where elevated percentages of polymers are part of the life cycle of gannets, especially during breeding. This baseline paper presents an analysis of litter content and its related impacts on the two gannet nests located in South France (Carry-Le-Rouet) and Northwest Italy (Portovenere) from 2017 to 2019. 654 items from both gannet nests were collected with 277 items (42%) being of natural origin, while 377 items (58%) were litter. Most of the nesting material was nautical cordage, which appears to be used preferentially. A more restrictive litter management regulation must be adopted to reduce litter generation from fishing/aquaculture-related activities.

Removal of polyethylene glycols from wastewater: A comparison of different approaches

Physicochemical methods such as adsorption on activated carbon, oxidation with either ozone or Fenton reagent, and chemical precipitation (coagulation), were assessed for the removal of polyethylene glycol (PEG) from wastewater. This contaminant is rarely investigated due to its low toxicity, although its presence limits the use of large water resources. The experimental tests showed that adsorption on activated carbon is well approximated by a Langmuir isotherm, and influenced by contact time, PEG molecular weight, pH, temperature, and initial PEG concentration. Ozonation allowed fragmenting the polymeric chains but was unable to remove completely the PEG, while about 85% of the total organic carbon (TOC) was removed by Fenton oxidation reaction by using a ratio between H₂O₂ and Fe^II close to 4. Coagulation did not produce results worthy of note, most likely because the uncharged PEG molecule does not interact with the iron hydroxide flocs. However, when performed after the Fenton oxidation (i.e., by simply raising the pH to values > 8), it allowed a further reduction of the residual TOC, up to 96% of the total, in the best case. Based on the resources used by each process studied and in consideration of the effectiveness of each of them, a semi-quantitative comparison on the sustainability of the different approaches is proposed.

Effect of Acid Leaching Pre-Treatment on Gold Extraction from Printed Circuit Boards of Spent Mobile Phones

The effect of a preliminary acid leaching for the recovery of gold by thiourea from printed circuit boards (PCBs) of spent mobile phones, was investigated. Preliminary leaching is aimed to recover copper in the leachate that would compete with gold in the successive leaching of the residue with thiourea, thus preventing the formation of the gold-thiourea complex. Two hydrometallurgical routes were tested for the recovery of copper first, and gold after. The first one was based on a two-step leaching that utilizes sulfuric acid and hydrogen peroxide in the preliminary leaching and then thiourea for the recovery of gold in the successive leaching: A copper and gold recovery of 81% and 79% were obtained, respectively. In the second route, nitric acid was used: 100% of copper was recovered in the leachate and 85% of gold in the thiourea successive leaching. The main operative parameters, namely thiourea and ferric sulphate concentrations, leach time, liquid-solid ratio, and temperature were studied according to a factorial plan strategy. A flowsheet of the processes was proposed, and a mass balance of both routes was obtained. Finally, qualitative considerations on the technical and economic feasibility of the different routes were made.

Microplastic-associated biofilms in lentic Italian ecosystems

In this study, 16S rRNA gene high throughput sequencing and Fluorescence In Situ Hybridization (FISH) combined with confocal laser scanning microscopy (CLSM) were used to assess for the first time biodiversity and structure of microplastic-associated biofilms (plastisphere) collected from Italian lentic ecosystems. The analysis revealed clear differences in microbial community composition among biofilms and corresponding planktonic populations indicating a selective adhesion on microplastics (MP). Although geographical variations in taxa composition were observed, a plastisphere core microbiome, composed by known biofilm formers found in freshwater ecosystems (e.g. Sphingorhabdus, Sphingomonas, Rhodobacter, Aquabacterium and Acidovorax genera) was found. Species composition of plastisphere did not substantially differ between the diverse polymers, while a clear link with the MP exposure time was found by Fourier Transform Infrared spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM) analysis. Generalist planktonic taxa (e.g. members of the families Sphingomonadaceae and Rhodobacteraceae) were found on MPs with the lowest degradation level whereas the biodiversity increased with the increase of MP degradation. FISH-CLSM analysis confirmed the Burkolderiaceae dominance in most of the analyzed plastisphere samples and revealed a patchy microbial colonization and a complex biofilm architecture with bacterial micro-colonies and cyanobacterial aggregates occurring together with microalgae assemblages.

Preparation and Characterization of TPP-Chitosan Crosslinked Scaffolds for Tissue Engineering

Scaffolds are three-dimensional porous structures that must have specific requirements to be applied in tissue engineering. Therefore, the study of factors affecting scaffold performance is of great importance. In this work, the optimal conditions for cross-linking preformed chitosan (CS) scaffolds by the tripolyphosphate polyanion (TPP) were investigated. The effect on scaffold physico-chemical properties of different concentrations of chitosan (1 and 2% w/v) and tripolyphosphate (1 and 2% w/v) as well as of cross-linking reaction times (2, 4, or 8 h) were studied. It was evidenced that a low CS concentration favored the formation of three-dimensional porous structures with a good pore interconnection while the use of more severe conditions in the cross-linking reaction (high TPP concentration and crosslinking reaction time) led to scaffolds with a suitable pore homogeneity, thermal stability, swelling behavior, and mechanical properties, but having a low pore interconnectivity. Preliminary biocompatibility tests showed a good osteoblasts’ viability when cultured on the scaffold obtained by CS 1%, TPP 1%, and an 8-h crosslinking time. These findings suggest how modulation of scaffold cross-linking conditions may permit to obtain chitosan scaffold with properly tuned morphological, mechanical and biological properties for application in the tissue regeneration field.

Hazard evaluation of plastic mixtures from four Italian subalpine great lakes on the basis of laboratory exposures of zebra mussels

Studies related to the evaluation of plastics in freshwaters have been increasing in recent years because approximately 80% of plastic items found in the sea are from inland waters. Despite the ecological relevance of these surveys, no information has been available until now about the hazard related to plastic mixtures in freshwaters. To fill this knowledge gap, we carried out a study aimed to assess the environmental risk associated with the "cocktail" of plastics and environmental pollutants adsorbed on their surface in one of the larger European freshwater basins. Plastic debris was collected by a manta trawl along one transect each in four of the Italian subalpine great lakes (Lake Maggiore, Como, Iseo and Garda) and administered to zebra mussels (Dreissena polymorpha), a useful freshwater biological model present in all these lakes. We estimated a plastic density from 4908 MPs/km² (Lake Iseo) to 272,261 MPs/km² (Lake Maggiore), while the most common polymers found were polyethylene and polypropylene, with percentages varying between 73% and 100%. A biomarkers suite consisting of 10 different endpoints was performed after 7 days of exposure to investigate the molecular and cellular effects of plastics and related adsorbed pollutants. The main results highlighted a diffuse but different toxicity due to plastics for each lake, and there were significant changes in the antioxidant and detoxifying enzyme activities in Lake Maggiore, Iseo and Garda, an increase in protein carbonylation in L. Como, and a cellular viability decrease of approximately 30% for zebra mussels from L. Iseo and Garda. Despite this variability in the endpoints' responses, the application of the biomarker response index showed a similar environmental hazard due to plastics for all the sampled lakes.

Arsenic accumulation in edible vegetables and health risk reduction by groundwater treatment using an adsorption process

The heavy metals transfer from the soil, where they accumulate, to the edible parts of the plants, and then, their entrance in the food chain can represent a source of concern for human health. Among heavy metals, arsenic is one of the most widespread in the soil of Lazio (central region of Italy), where the phytoavailable geogenic arsenic enters the food chain, with a dangerous exposition of the local population. In the first part of this work, plants of radish (Raphanus sativus L.) and lettuce (Lactuca sativa L.) were grown in protected culture in the experimental farm of CREA-AA, where they were daily treated with different concentrations of sodium arsenate dibasic heptahydrate in order to investigate differences in their arsenic accumulation capacities. In order to confirm the results achieved, in the second part of this study, the arsenic concentration was determined in commercial products obtained from contaminated areas of Lazio, and the potential exposition risk for human health through consumption of these widely consumed vegetables was estimated. The highest arsenic concentrations were found in the samples of lettuce. To evaluate the potential health risk from consumption of L. sativa and R. sativus, the estimated daily intake (EDI) for adults, adolescents, and elderly was calculated, finding that HRI (health risk index) index value for arsenic was low (< 1) in the case of chronic consumptions for all samples of radishes, and for the lettuces grown in the area of Viterbo. On the contrary, the lettuces obtained from Tuscania and Tarquinia presented very high concentrations of arsenic and a worrying HRI value. In order to reduce the risk of As toxicity in the people through consumption of the vegetables, the irrigation water should contain less than 0.1 mg As L-1. For this reason, the authors tested the application of red mud (RM) to remove As from groundwater before using it for the irrigation of radish and lettuce in greenhouse production.

Removal of Mn and As from drinking water by red mud and pyrolusite

Due to limited economic resources, which impede access to specific advanced technologies, many developing countries are still facing the challenge of reducing human exposure to heavy metals, which is primarily associated with the consumption of water contaminated through the discharge of poorly treated wastewater. In wastewater treatment technology, adsorption is sometime preferred to other approaches because of its high efficiency, easy handling, availability of different substrates and cost effectiveness. Moreover, increasing emphasis has recently been given to the use of low-cost adsorbents (generally solid wastes) for the treatment of polluted water, with a resulting double benefit for the environment. In this paper, the use of red mud and pyrolusite has been investigated for the removal of As and Mn from drinking water. Adsorption equilibrium data have been examined through the application of constant temperature models (isotherms), while batch and dynamic tests have been used to clarify the effects of pH, initial metal ion concentration and temperature on the adsorption performance, aiming at identifying the best conditions for the treatment. The combined use of the two adsorbents allows exploiting their properties synergistically, maximizing efficacy and sustainability without affecting process design and costs. In particular, 'clean' water (i.e. water with heavy metals contents below law limits) has been obtained even after the passage of a volume of solution higher than 40 bed volumes, and considering initial unrealistically high concentrations for the metals.

Fishing lines and fish hooks as neglected marine litter: first data on chemical composition, densities, and biological entrapment from a Mediterranean beach

We reported first data on the densities and chemical composition of fishing lines and fish hooks deposited on a Mediterranean beach. On a sampling area of 1.5 ha, we removed a total of 185,028 cm of fishing lines (density 12.34 cm/m²) and 33 hooks (density 22 units/ha). Totally, 637.62 g (42.5 mg/m²) of fishing lines were collected. We sampled 120 items entangled belongings to 7 animal taxa (density 6.49 items/100 m of fishing lines). We also observed a not quantifiable number of egagropiles (Posidonia oceanica spheroids), Rhodophyceae (Halymenia sp.) and segments of reeds of Phragmites communis, trapped in the fishing lines. Fourier transform infrared (FTIR) spectroscopy was used in order to identify the chemical composition of the fishing lines: 92% was made of nylon while 8.0% was determined as fluorocarbon based polymers (polyvinylidene fluoride). Because of their subtlety and reduced size, sandy beach cleaning operations should include at least two consecutive removal samplings: indeed, a part of this litter (12.14%) is not removed in the first sampling. The unexpected high density of fishing lines suggests specific management actions aimed to periodically remove this neglected anthropogenic litter.

Microplastics in Talitrus saltator (Crustacea, Amphipoda): new evidence of ingestion from natural contexts

Using Fourier transform infrared spectroscopy (FT-IR) measurements and comparing the spectrum peaks (range 4000-600 cm^-1) with reference spectra database and instrument libraries, we observed new evidence of the ingestion of microplastic particles analyzing the digestive tracts of Talitrus saltator. Specimens, sampled in central Italy, probably ingested the particles with natural detritus. Since worldwide many species of invertebrates and vertebrates (e.g., birds) feed on Amphipoda along coastal ecosystems, we hypothesized that microplastic in these crustaceans can be accumulated along the food chain.

Microplastic pollution in the surface waters of Italian Subalpine Lakes

Plastic debris incidence in marine environment was already highlighted in the early 1970s. Over the last decade, microplastic pollution in the environment has received increasing attention and is now an emerging research area. Many studies have focused on quantifying microplastic abundance in the marine environment, while there are relatively few data on microplastic occurrence in freshwater environment. Recent studies have reported high concentrations of microplastics in lakes and rivers, although the understanding of several factors influencing source, transport and fate is still limited. This study compares different lakes and the common factors, which could influence the occurrence and distribution of microplastics. The three subalpine lakes monitored include Lake Maggiore, Iseo and Garda. The selected sampling transects reflect the hydrologic conditions, the morphometric characteristics of these lakes, and other factors influencing the release of plastics debris in lakes. Particles of microplastics (<5 mm) were found in all sampled surfaces. The particles collected were classified depending on their number, shape and composition. The shape distribution showed the dominating occurrence of fragments (73.7%). The chemical composition of all examined samples clearly shows dominating presence of polyethylene (45%), polystyrene (18%) and polypropylene (15%). The results provide significant relations among the different contribution of direct and diffuse sources to the quantity of microplastics, highlighting the importance of understanding the spatial distribution dynamics of microplastics within a lake system that acts as a sink and source of plastic particles.

Pervasive plastisphere: First record of plastics in egagropiles (Posidonia spheroids)

The ability of Posidonia oceanica spheroids (egagropiles, EG) to incorporate plastics was investigated along the central Italy coast. Plastics were found in the 52.84% of the egagropiles collected (n = 685). The more represented size of plastics has range within 1-1.5 cm, comparable to the size of natural fibres. Comparing plastics occurring both in EG and in surrounding sand, Polyethylene, Polyester and Nylon were the most abundant polymers in EG, while PSE, PE, PP and PET were the most represented in sand. In particular PE and PP were significantly more represented in sand, while PE, Nylon, Polyester and microfibers (as pills) were more represented in EG. Within plastics found in EG, 26.9% were microfibers as small pills (<1 cm), mainly composed of polyamide, polyester, cotton and PET mixing. These microfibers might be produced by discharges from washing machines and currently represents an emerging pollutant with widespread distribution in marine and freshwater ecosystems.

Antimicrobial activity of catechol functionalized-chitosan versus Staphylococcus epidermidis

Protein mussel-inspired adhesive polymers, characterized by the presence of catechol groups, possess superior muco-adhesive properties and have great potentiality in wound healing. Suitable materials for wound dressing should properly combine muco-adhesiveness and antimicrobial activity. In this work, catechol-functionalized chitosan was obtained by reaction with hydrocaffeic acid (HCAF), in order to investigate how catechol introduction at different content could affect the intrinsic antimicrobial activity of the polymer itself. Unexpectedly, an enhancement of chitosan antimicrobial activity was observed after catechol functionalization, with a fourfold reduction in the polymer minimum inhibitory concentration versus Staphylococcus epidermidis. Additionally, a commercial wound dressing coated with one of the synthesized CS-HCAF derivatives showed a significant reduction in the adhesion of S. epidermidis compared to the uncoated dressing (3-log reduction). The CS-HCAF derivatives also showed an interesting antioxidant property (EC₅₀ ranging from 20 to 60μg/mL), which further confirms the potentiality of these materials as wound dressings.

Characterization of plastic beach debris finalized to its removal: a proposal for a recycling scheme

Characterization of beach debris is crucial to assess the strategy to answer questions such as recycling. With the aim to assess its use in a recycling scheme, in this note, we carried out a physical and chemical characterization of plastic litter from a pilot beach in Central Italy, using the FT-IR spectroscopy and thermoanalysis. Fourteen polymers, having mainly thermoplastic origin, were identified; among them, the most represented are polyethylene (41.7%) and polypropylene (36.9%). Chemical and mechanical degradation were clearly observed by an IR spectrum. The thermogravimetric analysis curve of the plastic blend shows the melting point at 120-140 °C, and degradation occurs almost totally in a one-step process within 300-500 °C. The high heating value of the plastic debris is 43.9 MJ kg^-1. Polymer blends obtained by beach debris show mechanical properties similar to the virgin high-density polyethylene polymer. Following the beach plastic debris characterization, a recycling scheme was suggested.

Plastisphere in action: evidence for an interaction between expanded polystyrene and dunal plants

Among the many threats that can be recorded on sandy beaches, plastic litter represents a serious problem for these complex and endangered ecosystems. Expanded polystyrene (EPS) is increasingly abundant as a form of plastic litter in natural environments, particularly along shores and waterways. Nevertheless, despite the great number of scientific articles concerning the impact of litter on animal species, there are still no research focusing on the interaction between this type of beach litter and other biodiversity components. In this work, we reported the first evidence of interactions between EPS and living plants along a sandy beach of Tyrrhenian central Italy. We sampled 540 EPS items, mainly deriving from fishery activities (>75%). We obtained evidence for an interaction between EPS and plants: about 5% of items resulted perforated or have roots of three species (Phragmites australis, Spartina versicolor, Anthemis maritima). Apparently, we did not observed a relationship between plants and EPS items size. More research is needed to assess if the plant assemblage growing on EPS is random or if peculiar substrate exerts some sort of selection on the plant community.

Fluoride Wastewater Treatment by Adsorption onto Metallurgical Grade Alumina

The adsorption of fluoride onto metallurgical grade alumina (to produce Al) was investigated under different conditions: pH, contact time and adsorbent concentration. Data were evaluated with the aim of developing an alternative treatment technology for washing wastewater arising from an Aluminum can production plant. Kinetics and adsorption isotherms data have been also produced Sorption is greatly affected by pH and the best condition for fluoride removal are obtained at pH 5-6 and alkalinity competes successfully with fluoride ions for the exchange sites. Experiments with fixed beds indicate that fluoride is removed from wastewater by metallurgical-grade alumina with a capacity of 12.21 mg of F per gram and adsorption increases of about 25% at appropriate pH. The Mass Transfer Zone at 5% of the breakthrough occupies 70.6% of the total column length. The optimization of aluminum precipitation by pH adjustment and with different precipitant agents has been done.

Characterization and leaching of NiCd and NiMH spent batteries for the recovery of metals

Since NiMH and NiCd batteries are still used in the electronic devices market, a treatment and recycling plant has many advantages both from the environmental and the economic points of view. Unfortunately, there is no relationship between shape, size and chemical composition of spent batteries, consequently the characterization and the leaching method of the starting material becomes an important step of the overall treatment process in choosing the best conditions for the selective separation of the metals by hydrometallurgy. Leaching at 20 degrees C with H(2)SO(4) 2M for about 2h seems to be a good solution in terms of cost and efficiency for both battery types. The hydroxide compounds can be readily leached while Ni present as metallic form requires more aggressive conditions due to kinetic constraints. In this paper, the characterization of NiMH and NiCd spent batteries and the results of leaching tests in different conditions are reported.

Chitosan Membrane: Tool for Chromium (III) Recovery from Aqueous Solutions

In this study four kinds of Chitosan membranes were prepared. The permeability of the membranes was then investigated by permeation of K+ in these membranes. The performances of the prepared membranes for recovery of chromium (III) from aqueous solution were evaluated. The effects of operation conditions on permeation characteristics were determined, and permeation mechanism was discussed. The stability of the membranes was also studied.

Reuse of residues arising from lead batteries recycle: a feasibility study

The performance of products arising from the stabilization/solidification of slags from lead batteries recycle into a Portland cement matrix has been evaluated not only in order to get a stabilized waste to be disposed of according to the current legislation, but also to obtain a recyclable material, with both economic and environmental benefits. Under this respect a detailed characterization of raw slags has been performed and different slag-cement samples have been prepared by varying the slag content. The parameters related to the cementation process have been evaluated and a series of tests on the final waste forms have been carried out, aimed at assessing both mechanical performance and leaching behaviour. In spite of the acceptable values for flexural, compressive and tensile strength, however, the high release of lead from the solidification products seems to be a limiting factor for a reusable material. While explanations of such phenomenon are given (high alkalinity of Portland cement; early "doping" of cementitious components by lead in the amorphous state), the main conclusion of the research work is that further efforts should be addressed to the adoption of a different or a modified incorporation matrix.

Use of amphotericin B colloidal dispersion in children

PURPOSE

To describe the experience with a new lipid-based amphotericin product (amphotericin B colloidal dispersion or ABCD) in children with fever and neutropenia who are at high risk for fungal infection.

PATIENTS AND METHODS

Forty-nine children with febrile neutropenia were treated in a prospective, randomized trial comparing ABCD with amphotericin B. An additional 70 children with presumed or proven fungal infection were treated with 5 different open-label studies of ABCD. Patients were registered into these studies for reasons of: 1) failure to respond to amphotericin B; 2) development of nephrotoxicity or preexisting renal impairment; or 3) willingness to participate in a dose-escalation study. Extensive data detailing response and toxicity were collected from each patient.

RESULTS

In the randomized trial, there was significantly less renal toxicity in the children receiving ABCD than in those receiving amphotericin B (12.0% vs. 52.4% [P = 0.003]). Other adverse symptoms were not significantly different. In the additional open-label studies, although 80% of patients receiving ABCD reported some adverse symptom, the majority of these were infusion related, and nephrotoxicity was reported in only 12% of these patients.

CONCLUSIONS

ABCD was well-tolerated at doses up to 5 times greater then those usually tolerated with amphotericin B. Renal toxicity was markedly less than expected, and there were no other unexpected severe toxicities. Further randomized studies are needed to further define the role of this and other liposomal products in children.

Renal sparing by amphotericin B colloidal dispersion: clinical experience in 572 patients

Data from five clinical trials of amphotericin B colloidal dispersion (ABCD) in the treatment of invasive mycoses were pooled to analyze the renal sparing effects of ABCD. Serum creatinine levels at baseline and either during or at end of treatment were available for 499 of 572 patients (87.2%). The median cumulative dose of ABCD administered to the 499 evaluable patients was 4,050 (range: 30-74,250) mg, and the median duration of treatment was 18 (range: 1-407) days. For the entire group of evaluable patients, the median change in serum creatinine during treatment with ABCD was -0. 1 mg/dl; for the subgroups of patients enrolled in the trials because of amphotericin B toxicity or preexisting renal impairment, the median changes in serum creatinine were -0.3 and -0.2 mg/dl, respectively. There was no trend of increasing serum creatinine with increasing cumulative dose of ABCD (correlation coefficient = -0. 016). ABCD was prematurely discontinued in 19 of 572 patients (3.3%) because of elevated serum creatinine levels. Unlike conventional amphotericin B, ABCD is not associated with dose-dependent nephrotoxicity.

Treatment of invasive fungal infections with amphotericin B colloidal dispersion in bone marrow transplant recipients

Amphotericin B colloidal dispersion (ABCD, AMPHOTEC, AMPHOCIL), a lipid complex of amphotericin B, was developed to reduce the nephrotoxicity of amphotericin B while retaining its antifungal efficacy. In this retrospective review, the efficacy and safety of ABCD were evaluated in 220 BMT recipients (167 allogeneic; 53 autologous) with suspected or documented life-threatening fungal infections (primarily Candida or Aspergillus species). Patients were treated in five open-label clinical trials of ABCD therapy. ABCD was administered intravenously once daily, median dose of 4 mg/kg, for up to 409 days (mean 23 days, median 16 days). Successful therapeutic response to treatment (complete or partial) was reported in 52% of the 99 evaluable patients with proven infection, and in 40% of all 220 patients. In the evaluable population, the response and mortality rates were 51% and 73%, respectively, in the allogeneic BMT patients, compared to 52% and 48% in the autologous BMT patients. The response rate for evaluable patients with Candida spp was 65%, 38% for patients with Aspergillus spp, and 42 % for patients with other or multiple fungal infections. In this patient population at high risk of nephrotoxicity due to concomitant cyclosporine and/or other nephrotoxic agents, ABCD did not cause renal dysfunction. Although the majority of patients had pre-existing renal impairment (median baseline serum creatinine 1.8 mg/dl), there was no trend towards increasing serum creatinine. No unexpected toxicities were observed. In conclusion, ABCD appears to be safe and effective for the treatment of severe fungal infections in BMT patients.

Amphotericin B colloidal dispersion for treatment of candidemia in immunocompromised patients

The efficacy and safety of amphotericin B colloidal dispersion (ABCD; Amphotec, Sequus Pharmaceuticals, Menlo Park, CA), a lipid complex of amphotericin B, were evaluated in immunocompromised patients with candidemia. These patients were recruited from five open-label clinical trials of ABCD therapy for fungal infections subsequent to bone marrow transplantation, hematologic malignancies, solid tumors, solid-organ transplantation, or other severe underlying disorders. ABCD was given intravenously in a median daily dose of 3.9 mg/kg for < or =72 days. Response rates were as follows: 53% overall (n = 88), 66% for patients with candidemia alone (n = 67), and 14% for patients with disseminated candidemia (n = 21). Nephrotoxicity occurred in 16% of patients, with either doubling of the baseline serum creatinine level or an increase of > or =1 mg/dL or a > or =50% decrease in calculated creatinine clearance. On average, there were no significant changes in the levels of serum creatinine or bilirubin from baseline to the end of treatment. In conclusion, ABCD was safe and effective for treating immunocompromised patients with candidemia.