Regeneration of Foam Electrodes Used for for the Removal of Mercury from Aqueous Solutions
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Program
Physics (MPPHS), MSc
Publicerad
2024
Författare
Gustafsson, Pontus
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Mercury is a heavy metal of great environmental concern. It possesses great environmental
mobility and is highly toxic for both humans and wildlife. An electrochemical
mercury decontamination technique that uses Pt-Hg alloy formation to
collect mercury from aqueous sources has been developed and shows great promise
and many advantages over existing techniques. The goal of this thesis is to study the
regenerative capacity of platinum-coated foam electrodes used in this technique over
decontamination cycles. Regeneration in this case refers to the re-release of mercury
in the form of Hg-ions via the oxidation of Pt-Hg alloy. Using a three-electrode
set-up in batch experiments, mercury was removed from 0.5 M sulphuric acid with
a mercury concentration of 1000 ppb using a platinum-coated stainless steel foam.
Mercury was also removed from contaminated concentrated sulphuric acid from a
zinc smelter using a platinum-coated RVC foam. Unfortunately, complete regeneration
was not achieved in any experiment, typically releasing less than half of the
collected mercury. This partial regeneration is likely due to suboptimal experimental
conditions. Despite this, the stability of the foams was demonstrated over multiple
formations/regenerations. The problems identified also highlight possible ways
forward for future research on the studied mercury decontamination technique. Decontamination
with the RVC foam in concentrated sulphuric acid managed to reach
mercury levels below the industry standard for high purity, something that has not
been presented in previously published research.
Beskrivning
Ämne/nyckelord
mercury, heavy metal, electrochemistry, decontamination, water treatment, regeneration.