Colloidal stability of nanoparticles derived from simulated cloud-processed mineral dusts
AbstractLaboratory simulation of cloud processing of three model dust types with distinct Fe-content (Moroccan dust, Libyan dust and Etna ash) and reference goethite and ferrihydrite were conducted in order to gain a better understanding of natural nanomaterial inputs and their environmental fate and bioavailability. The resulting nanoparticles (NPs) were characterised for Fe dissolution kinetics, aggregation/size distribution, micromorphology and colloidal stability of particle suspensions using a multi-method approach. We demonstrated that the: (i) acid-leachable Fe concentration was highest in volcanic ash (1mMg−1 dust) and was followed by Libyan and Moroccan dust with an order of magnit…
Metallic nanoparticle enrichment at low temperature, shallow CO2 seeps in Southern Italy
We report on metal enrichment along a natural pH gradient owing to increased CO2 degassing at cold, shallow seeps of Vulcano Island in the Mediterranean Sea, off Sicily. We assessed composition of unfiltered and filtered seawater (<100 nm) along acidic zones ranging between ambient and pH 5, and showed that most seep derived elements are present as nanoclusters which then aggregate into larger colloids while mixing with ambient seawater along a pH gradient. Size and elemental composition of such naturally occurring nanoparticles assessed by modern characterisation methods were in good agreement with the results from conventional analytical methods. We provide analytical evidence for the pre…
Image analysis from TEM and AFM micrograph, Table S1, S2, S3, Figure S1, Figure S2
We report on metal enrichment along a natural pH gradient owing to increased CO2 degassing at cold, shal- low seeps of Vulcano Island in the Mediterranean Sea, off Sicily. We assessed composition of unfiltered and filtered seawater (b100 nm) along acidic zones ranging between ambient and pH 5, and showed that most seep derived elements are present as nanoclusters which then aggregate into larger colloids while mixing with ambient seawater along a pH gradient. Size and elemental composition of such naturally occurring nanoparticles assessed by modern characterisation methods were in good agreement with the results from conventional analytical methods.We provide analytical evidence for the pr…