Bioremediation trial on PCB polluted soils. A bench study in Iceland

• Main Author: Lehtinen, Taru, 1981-
• Other Authors: Háskóli Íslands
• Format: Thesis
• Language: English
• Published: 2010
• Subjects: Jarðfræði; Umhverfis- og auðlindafræði; Jarðvegsmengun; Eiturefni; Jarðvegur; Reykjanes; Keflavík; Iceland
• Online Access: http://hdl.handle.net/1946/5454

Ritgerðin er lokuð til janúar 2011 Soils of today are under pressure of various pollutants, including polychlorinated biphenyls (PCBs) that are present in the soils at the old NATO facility in Keflavík, Iceland. Threats of PCBs to the environment are toxicity, ability to bioaccumulate, stability and low reactivity, low water solubility and high adsorption capacity to soil organic matter (Borja et al., 2005). The aim of this research was to propose a framework of protocols that can be adapted to bioremediate Icelandic soils that inhibit PCB contamination. To the author’s best knowledge, no data has been reported, neither on PCB degradation rates nor PCB degrading genes in Icelandic soils, and very limited research exists on contamination issues in Icelandic soils. The study was outlined as a two-phase remediation bench study where different biostimulation methods at different temperatures were conducted. The study likewise included a microbiology investigation of the soils and bioavailability to earthworms (Eisenia foetida). Pine needles biostimulation resulted in nearly 40 % degradation of total PCBs after two months incubation at 10°C. Successful amplification was obtained with aerobic PCB degrading gene bphA, and significantly different microbial communities were found in anaerobic soils compared to aerobic soils. Bioaccumulation factor (BAF) ranged from 0.82 to 0.89 in the earthworms, and both highly and less chlorinated congeners were accumulated. To conclude, a further small-scale field experiment with pine needles stimulation is recommended, with regular monitoring of the dynamic changes in the microbial communities in order to monitor early changes in other soil parameters. Kadeco, Rio Tinto Alcan