Microcosm and field experiments for remediation of acid pit lakes with bulk organic materials
Pit lakes represent a potentially valuable resource to mining companies, the environment and community in arid inland Australia. However, the water is often of low pH with high metal concentrations. Enhanced microbial sulphate reduction is potentially a cost effective and sustainable remediation strategy for these acid waters. Nevertheless, the availability of suitable organic substrates is typically limiting in these regions; most of the organic substrates evaluated to date are economically unsuited to the remote, arid areas where much of Australia's mining occurs.
In collaboration with Collinsville Coal Project, this project aims to evaluate municipal sewage and green waste as organic substrates for bacterially-mediated sulphate reduction at an entire-lake scale. We have conducted both onsite and Perth-based laboratory microcosm trials. We are now executing a field-scale experiment (with controls) involving the treatment of an entire acid coal pit lake in North Queensland, Australia, with municipal treated sewage and green waste. Raw sewage and green waste have been introduced into an acid mine void lake (150ml, pH 2.2) since July 2006. Monitoring of the biology and chemistry of this and three control lakes will continue over an 18 month period.
As a direct result of this project's inception, Collinsville won the "Ergon Energy, Environmental Innovation Award" in July, 2006.
Dr Clint McCullough
Associate Professor Mark Lund
Xstrata Coal Pty Ltd, Mr Joel May
Bowen Shire, Mr Gary Martins