Corrigendum: Colloidal nanomaterials for water quality improvement and monitoring.

[This corrects the article DOI: 10.3389/fchem.2022.

Colloidal nanomaterials for water quality improvement and monitoring.

Water is the most important resource for all kind forms of live. It is a vital resource distributed unequally across different regions of the globe, with populations already living with water scarcity, a situation that is spreading due to the impact of climate change. The reversal of this tendency and the mitigation of its disastrous consequences is a global challenge posed to Humanity, with the scientific community assuming a major obligation for providing solutions based on scientific knowledge.

In Vitro Hepatotoxic and Neurotoxic Effects of Titanium and Cerium Dioxide Nanoparticles, Arsenic and Mercury Co-Exposure.

Considering the increasing emergence of new contaminants, such as nanomaterials, mixing with legacy contaminants, including metal(loid)s, it becomes imperative to understand the toxic profile resulting from these interactions. This work aimed at assessing and comparing the individual and combined hepatotoxic and neurotoxic potential of titanium dioxide nanoparticles (TiONPs 0.75-75 mg/L), cerium oxide nanoparticles (CeONPs 0.

Mercury Removal from Aqueous Solution Using ETS-4 in the Presence of Cations of Distinct Sizes.

The removal of the hazardous Hg from aqueous solutions was studied by ion exchange using titanosilicate in sodium form (Na-ETS-4). Isothermal batch experiments at fixed pH were performed to measure equilibrium and kinetic data, considering two very distinct situations to assess the influence of competition effects: (i) the counter ions initially in solution are Na and Hg (both are exchangeable); (ii) the initial counter ions in solution are tetrapropylammonium (TPA) and Hg (only Hg is exchangeable, since TPA is larger than the ETS-4 micropores). The results confirmed that ETS-4 is highly selective for Hg, with more than 90% of the mercury being exchanged from the fluid phase.

Assessment of marine macroalgae potential for gadolinium removal from contaminated aquatic systems.

Gadolinium (Gd) is a rare earth associated with hospital and urban wastewaters due to its application as a contrast agent for magnetic resonance imaging. In this work, the uptake of Gd from contaminated seawater by three living marine macroalgae, Ulva lactuca (Chlorophyta), Fucus spiralis (Phaeophyta) and Gracilaria sp. (Rhodophyta) was studied along 72 h.

Spinel-type ferrite nanoparticles for removal of arsenic(V) from water.

Spinel ferrite particles (FeO, MnFeO, and CoFeO) were investigated as magnetic nanosorbents for removing arsenic from spiked water samples. The nanosorbents were collected via magnetic separation from aqueous solutions spiked with an arsenic concentration that mimics the amount of this contaminant in real water samples. This research shows that using amounts of CoFeO or MnFeO as low as 40 mg/L, the arsenic content in the contaminated water decreased for levels below the maximum admitted value by the World Health Organization for drinking waters (10 μg/L).

Negligible effect of potentially toxic elements and rare earth elements on mercury removal from contaminated waters by green, brown and red living marine macroalgae.

Mercury (Hg) removal by six different living marine macroalgae, namely, Ulva intestinalis, Ulva lactuca, Fucus spiralis, Fucus vesiculosus, Gracilaria sp., and Osmundea pinnatifida was investigated in mono and multi-contamination scenarios. All macroalgae were tested under the same experimental conditions, evaluating the competition effects with all elements at the same initial molar concentration of 1 μmol dm.

A green method based on living macroalgae for the removal of rare-earth elements from contaminated waters.

Low recycling rates of rare earth elements (REEs) are a consequence of inefficient, expensive and/or contaminating methods currently available for their extraction from solid wastes or from liquid wastes such as acid mine drainage or industrial wastewaters. The search for sustainable recovery alternatives was the motivation for this study. For the first time, the capabilities of 6 living macroalgae (Ulva lactuca, Ulva intestinalis, Fucus spiralis, Fucus vesiculosus, Osmundea pinnatifida and Gracilaria sp.

Unravelling the Potential Cytotoxic Effects of Metal Oxide Nanoparticles and Metal(Loid) Mixtures on A549 Human Cell Line.

Humans are typically exposed to environmental contaminants' mixtures that result in different toxicity than exposure to the individual counterparts. Yet, the toxicology of chemical mixtures has been overlooked. This work aims at assessing and comparing viability and cell cycle of A549 cells after exposure to single and binary mixtures of: titanium dioxide nanoparticles (TiONP) 0.

Valuation of banana peels as an effective biosorbent for mercury removal under low environmental concentrations.

The use of banana peels as biosorbent for mercury sorption from different aqueous solutions was investigated in this work. The impact of the operating conditions, such as biosorbent dosage, contact time and ionic strength was evaluated for realistic initial Hg(II) concentrations of 50 μg dm. Biosorbent dosage and contact time showed more influence on Hg(II) removal than ionic strength, and their increase led to improve Hg(II) uptake achieving final concentrations with drinking water quality.

Can contaminated waters or wastewater be alternative sources for technology-critical elements? The case of removal and recovery of lanthanides.

Technology critical elements (TCE) are considered the vitamins of nowadays technology. Factors such as high demand, limited sources and geopolitical pressures, mining exploitation and its negative impact, point these elements as new emerging contaminants and highlight the importance for removal and recycling TCE from contaminated waters. This paper reports the synthesis, characterization and application of hybrid nanostructures to remove and recover lanthanides from water, promoting the recycling of these high value elements.

Recovery of Rare Earth Elements by Carbon-Based Nanomaterials-A Review.

Modern societies depend strongly on electronic and electric equipment (EEE) which has a side effect result on the large production of electronic wastes (e-waste). This has been regarded as a worldwide issue, because of its environmental impact-namely due to non-adequate treatment and storage limitations. In particular, EEE is dependent on the availability of rare earth elements (REEs), considered as the "vitamins" of modern industry, due to their crucial role in the development of new cutting-edge technologies.

Reliable quantification of mercury in natural waters using surface modified magnetite nanoparticles.

Reliable determination of mercury (Hg) in natural waters is a major analytical challenge due to its low concentration and to the risk of Hg losses or contamination during sampling, storage and pre-treatment of samples. The present work proposes a simple, efficient, sensitive and easy-handling methodology for extraction, pre-concentration and quantification of total dissolved mercury in natural waters, using iron oxide nanoparticles (NPs) coated with silica shells functionalized with dithiocarbamate groups (FeO@SiOSiDTC). Ten mg L of these NPs were sufficient to remove 83-97% of 500 to 10 ng L of Hg in ultra-pure water and artificial seawater, used as model Hg solutions, within 24 h.

A macroalgae-based biotechnology for water remediation: Simultaneous removal of Cd, Pb and Hg by living Ulva lactuca.

Metal uptake from contaminated waters by living Ulva lactuca was studied during 6 days, under different relevant contamination scenarios. In mono-metallic solutions, with concentrations ranging from 10 to 100 μg L for Hg, 10-200 μg L for Cd, and 50-1000 μg L for Pb, macroalgae (500 mg L, d.w.

Bioaccumulation of Hg, Cd and Pb by Fucus vesiculosus in single and multi-metal contamination scenarios and its effect on growth rate.

Results of 7-days exposure to metals, using environmentally realistic conditions, evidenced the high potential of living Fucus vesiculosus to remove Pb, Hg and Cd from contaminated salt waters. For different contamination scenarios (single- and multi-contamination), ca 450 mg L (dry weight), enable to reduce the concentrations of Pb in 65%, of Hg in 95% and of Cd between 25 and 76%. Overall, bioconcentration factors ranged from 600 to 2300.

Mercury in river, estuarine and seawaters - Is it possible to decrease realist environmental concentrations in order to achieve environmental quality standards?

Dithiocarbamate-functionalized magnetite nanoparticles (FeO@SiO/SiDTC) have been investigated as a convenient and effective sorbent for mercury removal from river, estuarine and sea waters, and their capability to decrease realistic environmental concentrations to the new environmental quality standards was evaluated. The sorption kinetics was well described by the Elovich model and the initial sorption rate was dependent of the sorbent dose. Except for river water sample, the FeO@SiO/SiDTC particles uptake 99.

Remediation of mercury contaminated saltwater with functionalized silica coated magnetite nanoparticles.

The study aimed to evaluate the efficiency of dithiocarbamate functionalized silica coated magnetite nanoparticles (NPs) for Hg decontamination of saltwater either contaminated with Hg alone or with As and Cd. For this, the residual levels of Hg in seawater were assessed and Hg-contaminated or Hg+As+Cd-contaminated seawater toxicity to aquatic biota, before and after the sorption process, was compared. The results showed that under highly competitive conditions (water salts, Cd and As), the removal of Hg from seawater, by using these magnetic NPs, for the lowest concentration (50μg/L) was superior to 98% and for the highest concentration (500μg/L) ranged between 61% to 67%.

Comparative study on metal biosorption by two macroalgae in saline waters: single and ternary systems.

The biosorption capability of two marine macroalgae (green Ulva lactuca and brown Fucus vesiculosus) was evaluated in the removal of toxic metals (Hg, Cd and Pb) from saline waters, under realistic conditions. Results showed that, independently of the contamination scenario tested, both macroalgae have a remarkable capacity to biosorb Hg and Pb. In single-contaminant systems, by using only c.

Interference of the co-exposure of mercury with silica-coated iron oxide nanoparticles can modulate genotoxicity induced by their individual exposures--a paradox depicted in fish under in vitro conditions.

The study aimed to assess the genotoxic potential of silica-coated iron oxide nanoparticle functionalized with dithiocarbamate groups (IONP, 100 nm) in vitro exposure alone or its interference with mercury (Hg) co-exposure in the blood of European eel (Anguilla anguilla L.) by evaluating 8-hydroxy-2'-deoxyguanosine (8-OHdG), lipid peroxidation (LPO), and erythrocytic nuclear abnormalities (ENA). Four groups were made: (i) 2 × 10(6) erythrocytes + Roswell Park Memorial Institute-1640 (RPMI-1640) (control), (ii) 2 × 10(6) erythrocytes + IONP (2.

Ferromagnetic sorbents based on nickel nanowires for efficient uptake of mercury from water.

This work reports the preparation of ferro-magnetic nickel nanowires (NiNW) coated with dithiocarbamate-functionalized siliceous shells and its application for the uptake of aqueous Hg(II) ions by magnetic separation. NiNW with an average diameter and length of 35 nm and 5 μm, respectively, were firstly prepared by Ni electrodeposition in an anodic aluminum oxide template. The NiNW surfaces were then coated with siliceous shells containing dithiocarbamate groups via a one-step procedure consisting in the alkaline hydrolytic co-condensation of tetraethoxysilane (TEOS) and a siloxydithiocarbamate precursor (SiDTC).

A multidisciplinary approach to evaluate the efficiency of a clean-up technology to remove mercury from water.

A microporous material denoted ETS-4 was used as the decontaminant agent to treat water with a low level of Hg contamination. The effectiveness of the treatment was evaluated by assessment of the efficiency of Hg removal and ecotoxicological responses. The results showed that under highly competitive conditions the removal of Hg ranged between 58 % and 73 % depending upon the initial Hg concentration, and that Hg removal was reflected in decreased toxicity to some organisms.

Efficiency of a cleanup technology to remove mercury from natural waters by means of rice husk biowaste: ecotoxicological and chemical approach.

In the present work, the efficiency of rice husk to remove Hg(II) from river waters spiked with realistic environmental concentrations of this metal (μg L(-1) range) was evaluated. The residual levels of Hg(II) obtained after the remediation process were compared with the guideline values for effluents discharges and water for human consumption, and the ecotoxicological effects using organisms of different trophic levels were assessed. The rice husk sorbent proved to be useful in decreasing Hg(II) contamination in river waters, by reducing the levels of Hg(II) to values of ca.

Competitive effects on mercury removal by an agricultural waste: application to synthetic and natural spiked waters.

In this work, the efficiency of a local and highly, available agricultural waste, the raw rice husk, was used to remove mercury (Hg) from synthetic and natural waters, spiked with concentrations that reflect the contamination problems found in the environment. Different operating conditions were tested, including initial pH, ionic strength, the presence of co-ions (cadmium) and organic matter. The sorption efficiency of rice husk was slightly affected by the presence H+ ions (pH range between 3 and 9), but in the presence of NaNO3 and NaCl electrolytes and in binary solutions containing Cd2+ and H2+, the sorption efficiency was dependent on the nature and levels of the interfering ion and on the initial concentration of Hg+ used.

Cork stoppers as an effective sorbent for water treatment: the removal of mercury at environmentally relevant concentrations and conditions.

The technical feasibility of using stopper-derived cork as an effective biosorbent towards bivalent mercury at environmentally relevant concentrations and conditions was evaluated in this study. Only 25 mg/L of cork powder was able to achieve 94 % of mercury removal for an initial mercury concentration of 500 μg/L. It was found that under the conditions tested, the efficiency of mercury removal expressed as equilibrium removal percentage does not depend on the amount of cork or its particle size, but is very sensitive to initial metal concentration, with higher removal efficiencies at higher initial concentrations.

Nanoscale materials and their use in water contaminants removal-a review.

Water scarcity is being recognized as a present and future threat to human activity and as a consequence water purification technologies are gaining major attention worldwide. Nanotechnology has many successful applications in different fields but recently its application for water and wastewater treatment has emerged as a fast-developing, promising area. This review highlights the recent advances on the development of nanoscale materials and processes for treatment of surface water, groundwater and industrial wastewater that are contaminated by toxic metals, organic and inorganic compounds, bacteria and viruses.