[en] Stainless steel weld metal specimens (304 L) with different ferrite contents were cathodically charged at room temperature. The microcrack nucleation sites were observed by scanning electron microscopy (SEM). The role of delta ferrite content on hydrogen embrittlement was assessed by bend tests

No abstract available

[en] Highlights: • Evaluating CFH-12® and Phoslock® as P adsorbents during anoxia and resuspension. • P efflux reduction: 88% (CFH-12®) and 98% (Phoslock®) after 54-days anoxic period. • P efflux reduction: 84% (CFH-12®) and 88% (Phoslock®) after resuspension. • No release of Fe from CFH-12® during anoxia and resuspension. Laboratory experiments with intact sediment cores from a hypertrophic very windy exposed shallow lake were conducted to assess the combined effect of anoxia and sediment resuspension on phosphorus (P) dynamics after adding different P adsorbents (CFH-12® and Phoslock®). In this study we hypothesize that the addition of geoengineering materials will increase P retention in the sediment even at the worst physic-chemical conditions such as anoxia and sediment resuspension. Both adsorbents significantly reduced the P release from the sediments after a 54 days-anoxic incubation period (CFH-12® by 85% and Phoslock® by 98%) and even after resuspension events (CFH-12® by 84% and Phoslock® by 88%), indicating that both adsorbents are suitable P inactivating agents for restoring shallow eutrophicated lakes under such circumstances. CFH-12® did not release dissolved Fe to the water column neither after the anoxic period nor after resuspension events compared to Control (no adsorbents addition). The La concentration was significantly higher in Phoslock® (3.5–5.7 μg L⁻¹) than in Control at all sampling days but it was not affected by resuspension. The high efficiency in P removal under anoxia and resuspension, the low risk of toxicity and the high maximum adsorption capacity makes CFH-12® a promising adsorbent for lake restoration. Nevertheless, further research about the influence of other factors (i.e. pH, alkalinity, interfering substances or strict anoxia) on the performance of CFH-12® is needed.

[en] Highlights: • Microcosms experiment was used for assessing MPs effects on zooplankton community. • MPs did not promote significant effect in zooplankton community. • No significant changes on any physico-chemical or biological drivers were found. • MPs can be proposed as a promising tool for removing P. -- Abstract: Magnetic microparticles (MPs) have been recently proposed as innovative and promising dissolved inorganic phosphorus (DIP) adsorbents. However, before using them in a whole-lake restoration project, it is essential to assess their toxicological effects (direct and indirect) on aquatic biota. In the present study we hypothesized that zooplankton community is affected by MPs used for lake restoration. To test our hypothesis we designed a microcosms experiment (n = 15) containing lake water and surface sediment from a hypertrophic lake. Temporal changes (70 days) on physico-chemical conditions and on zooplankton structure (rotifers, copepods and branchiopods) were monitored under different scenarios. In particular, three different treatments were considered: no addition of MPs (control) and MPs addition (1.4 g MPs L⁻¹) on the surface water layer (T-W) and on the sediment (T-S). After 24 h of contact time, MPs were removed with a magnetic rake. A total of 15 zooplankton species (12 rotifers, 1 branchiopod and 2 copepods) were recorded and a high abundance of zooplankton was registered during the experiment for all treatments. No significant differences (RM-ANOVA test; p > 0.05) in total abundance, species richness and species diversity among treatments were found. The absence of any effect of MPs on zooplankton can be explained because MPs did not significantly alter any of its physico-chemical (e.g. temperature, pH, O₂) or biological (e.g. food quantity and quality) drivers. These results confirm the suitability of MPs as a promising tool for removing DIP in eutrophic aquatic ecosystems.