Toxicological evaluation of acid mine drainage waste waterudtreatment options at Mt Lyell, Tasmania: Mount Lyell Acid Drainage Remediation Program,

摘要

A primary aim of the development of an acid drainage treatment plant at Mt Lyell is theudpartial to complete rehabilitation of aquatic ecosystems in the lower King Riverud(downstream of the junction with the Queen River) and upper Macquarie Harbour. Audnumber of primary environmental remediation targets have been identified for thisudsystem. These include partial or complete recovery of macroinvertebrate and fishudcommunities in the lower King River, partial or complete recovery of native fishudrecruitment into tributaries of the lower King River, no mortality or inhibition of growthudof salmonids in aquacultural operations in northern Macquarie Harbour.ududA suite of toxicological tests were conducted to assess the relative success of three mainudtreatment options for wastewaters from the proposed treatment plant at achieving theudproposed remediation targets. Three 'test waters' were prepared from acid mine drainageud(AMD) waters collected from the Mt Lyell lease. They were: pH 3.6 with sulphidisationud(to simulate Cu removal by sulphide generating bacteria), pH 7.5 and pH 6.3. The latterudtwo test waters were prepared by neutralisation of AMD with quicklime, followed byudseparation of supernatant from precipitates. The pH 3.6 test water was produced byudpartial neutralisation with limestone slurry, treatment of supernatant with sodiumudhydrogen sulphide and separation of supernatant.