Petroleum Hydrocarbon Remediation in Antarctica, the use of PRB's
Petroleum hydrocarbons from fuel spills are the principal source of contamination in Antarctica. Recently, polar remediation technology has focused on the bio stimulation of indigenous hydrocarbon degrading micro-organisms. However, there has been little attention on the development of controlled release nutrient (CRN) systems to optimise microbial degradation.
Zeolites, in particular clinoptilolite ((Ca,Na2,K2)3[A16Si30O72].24H2O), have been identified as a substrate for a CRN systems via an ion exchange mechanism. However, as Antarctic soil water generally has a low ionic strength, an exchanging cation must be introduced as a component of the nutrient release system. This is achieved via the addition of a calcium phosphate material or a synthetic apatite to the zeolite.
This work focuses on the determination of the equilibria interaction between ammonium located in the pores of a zeolite and exchanging cations likely to be present in the local subsurface environment i.e. Na+, Ca2+, K+, Mg2+. It includes the effect of temperature on the selectivity of the clinoptilolite, and freezing on the hydraulic performance of the system. Results will be presented from batch and column studies as well as a permeable reactive barrier system installed at Casey Station, Antarctica.