A permeable reactive barrier (PRB) media sequence for the remediation of heavy metal and hydrocarbon contaminated water: A field assessment at Casey Station, Antarctica

• A sequenced PRB for heavy metal and hydrocarbon removal was constructed in Antarctica.
• Tracer testing, coring and water samples were used to assess performance over two summers.
• Enhanced phosphorus removal was achieved relative to existing PRBs at the site.
• Non-ideal flow was observed during the second summer.

A field trial was conducted at Casey Station, Antarctica to assess the suitability of a permeable reactive barrier (PRB) media sequence for the remediation of sites containing both hydrocarbon and heavy metal contamination. An existing PRB was modified to assess a sequence consisting of three sections: (i) Nutrient release/hydrocarbon sorption using ZeoPro™ and granular activated carbon; (ii) Phosphorus and heavy metal capture by granular iron and sand; (iii) Nutrient and excess iron capture by zeolite.The media sequence achieved a greater phosphorus removal capacity than previous Antarctic PRB configurations installed on site. Phosphorus concentrations were reduced during flow through the iron/sand section and iron concentrations were reduced within the zeolite section. However, non-ideal flow was detected during a tracer test and supported by analysis of media and liquid samples from the second summer of operation. Results indicate that the PRB media sequence trialled might be appropriate for other locations, especially less environmentally challenging contaminated sites.