Layer-by-Layer Deposition of Titanium Dioxide Nanoparticles on Polymeric Membranes: A Life Cycle Assessment Study

Membrane processes are widely used in wastewater treatment and for removal of contaminants from drinking water. Engineered nanomaterials (ENMs) can be integrated into membranes structure to enhance their performance (e.g., fouling mitigation and improvement of permeate quality). However, in order to ensure a sustainable use of nanoactivated membrane, the potential environmental impacts should be evaluated in an early stage of their development. In this study, we performed a cradle to gate life cycle assessment (LCA) to evaluate the environmental impacts due to the integration of titanium dioxide (TiO₂) engineered nanoparticles (ENPs) in polyethersulfone (PES) membrane using the layer-by-layer (LbL) technology. The PES membrane manufacturing and electrostatic deposition of TiO₂ ENPs on PES membrane were investigated in this case study. The results show that the LbL deposition stage of TiO₂ ENPs on membrane has an insignificant effect on all selected impact categories, in comparison to PES membrane manufacturing stages investigated. The electricity use during the membrane production as well as the solvents and polymers needed for making PES membrane are the main contributions to the overall environmental impact

TEM images of n-ZnO suspensions (10 µg/ml in ASW) (A) and their intracellular localisation in mussel hemocytes (B–C).

<p>Hemocytes were incubated with n-ZnO (10 µg/ml in ASW) for different periods of time as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0036937#s4" target="_blank">Methods</a>. B) n-ZnO (30 min). Squares indicate the presence of n-sized ZnO particles within multivesicular endosomes (end). C) n-ZnO (60 min). An apoptotic cell is shown.</p

Primary physical and chemical properties of selected NPs.

1<p>–by TEM, TEM-EDX, SAED.</p>2<p>–by BET.</p>3<p>–declared by the supplier.</p>4<p>–by ICP-OES.</p

Average size distributions of selected NP suspensions in ASW at different times after sonication, as determined by Dynamic Light Scattering (DLS).

<p>Average size distributions of selected NP suspensions in ASW at different times after sonication, as determined by Dynamic Light Scattering (DLS).</p

Effects of n-TiO₂, n-SiO₂, n-ZnO, n-CeO₂ on extracellular oxyradical production by mussel hemocytes.

<p>A) Total oxyradical production; B) Superoxide anion (O₂⁻) production. Hemocytes were exposed for 30 min to different concentrations of n-oxides (1, 5, 10 µg/ml) and total extracellular oxyradical production was evaluated as cytochrome c reduction as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0036937#s4" target="_blank">Methods</a> (A). In a parallel set of samples, superoxide dismutase-SOD (300 Units/ml) was included to allow specific evaluation of superoxide (O₂⁻) generation (B). Data, representing the mean±SD of four experiments in triplicate, were analysed by ANOVA followed by Tukey’s post hoc test. *  =  P≤0.01, all treatments <i>vs</i> controls.</p

TEM images of n-TiO₂ suspensions and their intracellular localisation in mussel hemocytes.

<p>Hemocytes were incubated with n-TiO₂ (10 µg/ml in ASW) for 30 and 60 min as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0036937#s4" target="_blank">Methods</a>. A) n-TiO₂ suspensions (10 µg/ml in ASW); B) Control cells, showing lysosomal (lys) and endosomal structures (end); C) n-TiO₂ (30 min), showing the presence of TiO₂ agglomerates within an endosome (end). D) n-TiO₂ (60 min). The square indicates the presence of n-sized TiO₂ within the nucleus (N) (see enlargement at the bottom left).</p

Empowering citizens in international governance of nanotechnologies

The international dialogue on responsible governance of nanotechnologies engages a wide range of actors with conflicting as well as common interests. It is also characterised by a lack of evidence-based data on uncertain risks of in particular engineered nanomaterials. The present paper aims at deepening understanding of the collective decision making context at international level using the grounded theory approach as proposed by Glaser and Strauss in "The Discovery of Grounded Theory'' (1967). This starts by discussing relevant concepts from different fields including sociological and political studies of international relations as well as political philosophy and ethics. This analysis of current trends in international law making is taken as starting point for exploring the role that a software decision support tool could play in multi-stakeholder global governance of nanotechnologies. These theoretical ideas are then compared with the current design of the SUN Decision Support System (SUNDS) under development in the European project on Sustainable Nanotechnologies (SUN, www.sun-fp7.eu). Through constant comparison, the ideas are also compared with requirements of different stakeholders as expressed during a user workshop. This allows for highlighting discussion points for further consideration

Accurate Prediction of the Response of Freshwater Fish to a Mixture of Estrogenic Chemicals-1

<p><b>Copyright information:</b></p><p>Taken from "Accurate Prediction of the Response of Freshwater Fish to a Mixture of Estrogenic Chemicals"</p><p>Environmental Health Perspectives 2005;113(6):721-728.</p><p>Published online 14 Mar 2005</p><p>PMCID:PMC1257597.</p><p>This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original DOI.</p

Environmental Impacts by Fragments Released from Nanoenabled Products: A Multiassay, Multimaterial Exploration by the SUN Approach

Nanoenabled products (NEPs) have numerous outdoor uses in construction, transportation or consumer scenarios, and there is evidence that their fragments are released in the environment at low rates. We hypothesized that the lower surface availability of NEPs fragment reduced their environmental effects with respect to pristine nanomaterials. This hypothesis was explored by testing fragments generated by intentional micronisation (“the SUN approach”; Nowack et al. Meeting the Needs for Released Nanomaterials Required for Further Testing: The SUN Approach. <i>Environmental Science & Technology</i>, <b>2016</b> (<i>50</i>), 2747). The NEPs were composed of four matrices (epoxy, polyolefin, polyoxymethylene, and cement) with up to 5% content of three nanomaterials (carbon nanotubes, iron oxide, and organic pigment). Regardless of the type of nanomaterial or matrix used, it was observed that nanomaterials were only partially exposed at the NEP fragment surface, indicating that mostly the intrinsic and extrinsic properties of the matrix drove the NEP fragment toxicity. Ecotoxicity in multiple assays was done covering relevant media from terrestrial to aquatic, including sewage treatment plant (biological activity), soil worms (<i>Enchytraeus crypticus</i>), and fish (zebrafish embryo and larvae and trout cell lines). We designed the studies to explore the possible modulation of ecotoxicity by nanomaterial additives in plastics/polymer/cement, finding none. The results support NEPs grouping by the matrix material regarding ecotoxicological effect during the use phase. Furthermore, control results on nanomaterial-free polymer fragments representing microplastic had no significant adverse effects up to the highest concentration tested

Environmental Impacts by Fragments Released from Nanoenabled Products: A Multiassay, Multimaterial Exploration by the SUN Approach

Nanoenabled products (NEPs) have numerous outdoor uses in construction, transportation or consumer scenarios, and there is evidence that their fragments are released in the environment at low rates. We hypothesized that the lower surface availability of NEPs fragment reduced their environmental effects with respect to pristine nanomaterials. This hypothesis was explored by testing fragments generated by intentional micronisation (“the SUN approach”; Nowack et al. Meeting the Needs for Released Nanomaterials Required for Further Testing: The SUN Approach. <i>Environmental Science & Technology</i>, <b>2016</b> (<i>50</i>), 2747). The NEPs were composed of four matrices (epoxy, polyolefin, polyoxymethylene, and cement) with up to 5% content of three nanomaterials (carbon nanotubes, iron oxide, and organic pigment). Regardless of the type of nanomaterial or matrix used, it was observed that nanomaterials were only partially exposed at the NEP fragment surface, indicating that mostly the intrinsic and extrinsic properties of the matrix drove the NEP fragment toxicity. Ecotoxicity in multiple assays was done covering relevant media from terrestrial to aquatic, including sewage treatment plant (biological activity), soil worms (<i>Enchytraeus crypticus</i>), and fish (zebrafish embryo and larvae and trout cell lines). We designed the studies to explore the possible modulation of ecotoxicity by nanomaterial additives in plastics/polymer/cement, finding none. The results support NEPs grouping by the matrix material regarding ecotoxicological effect during the use phase. Furthermore, control results on nanomaterial-free polymer fragments representing microplastic had no significant adverse effects up to the highest concentration tested