Advances in the Fate of Rare Earth Elements, REE, in Transitional Environments: Coasts and Estuaries

The production of rare earth elements, REE, has significantly increased over the past years, in parallel with the latest advances in nanotechnologies and representing a new group of emerging contaminants. They find application in construction, transport, agriculture, electronics, catalysis, and biomedicine. Their extraordinary intrinsic characteristics are fundamental for overcoming current technological challenges. The accumulation of REE is consistent in near-shore waters being affected by runoff, wastewater discharge, and proximity to built-up areas. Bioavailability in water, sediments, and accumulation in marine biota as well their endocrine disruptor effect is mostly unknown. There is a significant gap of knowledge on the ecotoxicological behaviour of REE in marine areas. The existing investigations have been performed inside well-mixed estuarine systems, due to complex hydrodynamics and multiple sediment transport situations. This hampers the definition of regulatory thresholds for REE concentrations and emissions. The review summarizes the existing information on REE geochemistry and physicochemical conditions influencing dissolution, surface complexation reactions, and distribution at the continent–ocean interface, as well as their speciation, bioavailability, and detrimental effects on living organisms. Strategies for reducing REE usage and inputs are also discusse

In situ microcosm remediation of polyaromatic hydrocarbons: influence and effectiveness of Nano-Zero Valent Iron and activated carbon

: Nano-zero-valent iron (nZVI) and activated carbon (AC) addition are ongoing techniques for the remediation of hydrophobic organic compound-contaminated sediment and water, but with still unexplored eco(toxico)logical implications, especially when applied in situ. In this study, we investigated AC and nZVI as remediation methods for marine contaminated sediment and water, including chemical and toxicity (Artemia franciscana survival and genotoxicity) surveys. The removal efficiency of AC and nZVI (about 99%) was similar in both sediment and seawater, while the survival of nauplii and adults was mainly impacted by nZVI than AC. At the molecular level, the nZVI-addition induced down-regulation in the expression of two stress and one developmental genes, whereas AC was able to up-regulated only one gene involved in stress response. Results suggested that the use of AC is safer than nZVI that requires further investigation and potential optimization to reduce secondary undesired effects

Exploring Avoided Environmental Impacts as Well as Energy and Resource Recovery from Microbial Desalination Cell Treatment of Brine

Seawater represents a potential resource to ensure sustainable availability of water for population and irrigation purpose, especially in some areas of the world. Desalination processes allow the production of fresh water, but they generate also brine as waste product. Sustainable brine man-agement should be identified to ensure proper disposal, and potentially resource recovery. This ex-perimental study shows that emerging technologies such as Microbial Desalination Cells (MDCs) may provide a valuable contribution to the sustainability of seawater desalination sector. In this paper, we report results on lab-scale desalination brine treatments applying MDCs – which allow energy savings, resource recovery, environmental impact minimization, and reduction of the or-ganic load in municipal wastewater. Our results show that MDCs treatment allows the removal of approximately 33 g of salts (62% of the total) – including chlorides, bromides, and sulphates – from 20 mL of brine within 96 hours. The MDCs, according to the source of energy and the presence of mature biofilm at the anode, spent 7.2 J, 7.9 J and 9.6 J in the desalination process, with the higher amount of energy required by the abiotic system and the lesser by the MDCs fed with just wastewater. Our approach also shows environmental and energy reductions because of potential metal recovery instead of returning them into marine environment. We quantify the avoided life cy-cle human and marine eco-toxicity impacts as well as the reduction of cumulative energy demand of recovered metals. The main benefit in terms of avoided toxicity would arise from the mercury and copper recovery, while potential economic advantages would derive from the recovered cobalt that represents a strategic resource for many products such as battery storage systems

Coffee Silverskin: Chemical and Biological Risk Assessment and Health Profile for Its Potential Use in Functional Foods

The coffee supply chain is characterized by a complex network with many critical and unsustainable points producing a huge amount of waste products. Among these, coffee silverskin (CS), the only by-product of the coffee roasting phase, has an interesting chemical profile that suggests potential use as a food ingredient. However, few data on its safety are available. For this reason, the purpose of the study was to assess the occurrence of chemical and biological contaminants in CS, and the resulting risk due to its potential consumption. Essential, toxic, and rare earth elements, polycyclic aromatic hydrocarbons (PAHs), process contaminants, ochratoxin A (OTA), and pesticides residues were analyzed in three classes of samples (Coffea arabica CS, Coffea robusta CS, and their blend). Furthermore, total mesophilic bacteria count (TMBC) at 30 C, Enterobacteriaceae, yeasts, and molds was evaluated. The risk assessment was based upon the hazard index (HI) and lifetime cancer risk (LTCR). In all varieties and blends, rare earth elements, pesticides, process contaminants, OTA, and PAHs were not detected except for chrysene, phenanthrene, and fluoranthene, which were reported at low concentrations only in the arabica CS sample. Among essential and toxic elements, As was usually the most representative in all samples. Microorganisms reported a low load, although arabica and robusta CS showed lower contamination than mixed CS. Instead, the risk assessment based on the potential consumption of CS as a food ingredient did not show either non-carcinogenic or carcinogenic risk. Overall, this study provides adequate evidence to support the safety of this by-product for its potential use in functional foods

Infralittoral ostracoda and benthic foraminifera of the Gulf of Pozzuoli (Tyrrhenian Sea, Italy)

AbstractThe shallow water benthic foraminiferal and ostracod assemblages of the Gulf of Pozzuoli, located in the central Tyrrhenian Sea, were studied to investigate the relationship between calcareous meiofaunas and contaminant concentrations in bottom sediments exposed to prolonged industrial pollution. Both benthic foraminifers and ostracods displayed high-diversity and low-dominance, unusual features in highly contaminated environments. High-diversity values were possibly linked to the oligotrophic, well-oxygenated, and CaCO3-supersaturated coastal Mediterranean waters. The comparison with historical data suggested that assemblage composition changed in the last decades, with an increase in the relative abundance of benthic foraminiferal (Quinqueloculina seminulum, Bulimina elongata) and ostracod (Xestoleberis,Loxoconcha, Semicytherura rarecostata) taxa. They probably represent organisms tolerant to the environmental variations in the last decades. The relationships between granulometry and diversity indices, high correlation values betweenQuinqueloculina lataand heavy metal pollution, and the preference of the ostracod generaUrocythereisandParacytherideafor very shallow marine waters were highlighted

Evaluation of Microbial Communities of Bottled Mineral Waters and Preliminary Traceability Analysis Using NGS Microbial Fingerprints

The microbiological monitoring of mineral bottled waters results is crucial for the prevention of outbreaks in consumers. European and International regulations establish the quality of water intended for human consumption in order to preserve human health from the negative effects deriving from water contamination. Advanced methods targeting the faster detection of potential pathogens in drinking water may consent to the creation of an early warning system, enhancing water quality management. This study aimed to suggest the implementation of standard water quality evaluations, based on the characterization of the microbial composition of mineral bottled water brands, contributing to the periodic control of the water’s microbiological stability along with the shelf life, and, consequently, the stability of the supplying sources. Bottled water microbiota analysis was combined with the qualitative and quantitative evaluation of microbial loads in time, and the monitoring was performed in two seasons and two different storage conditions for a total of sixty days. The employment of molecular microbiology techniques (NGS and Sanger sequencing), compared to standardized cultural methods and integrated with metagenomic analysis, combining chemical and physical indicators for each sample, allowing for the generation of specific fingerprints for mineral bottled waters, pointing at simplifying and improving the foreseen risk assessment strategies to ensure the adequate traceability, quality and safety management of drinking water

Resolving the effects of environmental micro- and nanoplastics exposure in biota: A knowledge gap analysis

The pervasive spread of microplastics (MPs) and nanoplastics (NPs) has raised significant concerns on their toxicity in both aquatic and terrestrial environments. These polymer-based materials have implications for plants, wildlife and human health, threatening food chain integrity and ultimate ecosystem resilience. An extensive – and growing – body of literature is available on MP- and NP-associated effects, including in a number of aquatic biota, with as yet limited reports in terrestrial environments. Effects range from no detectable, or very low level, biological effects to more severe outcomes such as (but not limited to) increased mortality rates, altered immune and inflammatory responses, oxidative stress, genetic damage and dysmetabolic changes. A well-established exposure route to MPs and NPs involves ingestion with subsequent incorporation into tissues. MP and NP exposures have also been found to lead to genetic damage, including effects related to mitotic anomalies, or to transmissible damage from sperm cells to their offspring, especially in echinoderms. Effects on the proteome, transcriptome and metabolome warrant ad hoc investigations as these integrated “omics” workflows could provide greater insight into molecular pathways of effect. Given their different physical structures, chemical identity and presumably different modes of action, exposure to different types of MPs and NPs may result in different biological effects in biota, thus comparative investigations of different MPs and NPs are required to ascertain the respective effects. Furthermore, research on MP and NP should also consider their ability to act as vectors for other toxicants, and possible outcomes of exposure may even include effects at the community level, thus requiring investigations in mesocosm models

A first attempt to evaluate the toxicity to Phaeodactylum tricornutum Bohlin exposed to rare earth elements

The increasing use and demand of rare earth elements in many emerging technologies is leading to a potentially higher input to the marine environment. This study compared for the first time the effect of lanthanum (La), cerium (Ce), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), and erbium (Er) to the microalga Phaeodactylum tricornutum Bohlin. The algal growth inhibition was investigated after 72 h of exposure. The median effect concentrations (EC50) ranged from 0.98 mg/L to 13.21 mg/L and elements were ranked as follows: Gd > Ce > Er > La > Eu > Nd > Dy > Sm. The comparison of predicted no effect concentrations (PNEC) for hazard and risk assessment with measured environmental concentrations showed that ecological risks deriving from REEs could be present, but limited to specific environments like estuarine waters. The results support evidence of actions to manage the REE impact in seawater environments, looking to improve the monitoring tailored to the different and dynamic nature of ecosystems