Chemical clogging of granular media under acidic groundwater conditions

Generation of acidic groundwater attributed to pyrite oxidation in low-lying acid sulfate soil has caused substantial damage the soil-water environment and civil infrastructure coastal Australia. The installation permeable reactive barriers (PRBs) is a frontier technology field neutralisation removal toxic heavy metal cations – for example, soluble iron (Fe) aluminium (Al). This study aims assess potential limestone (calcite) aggregates as PRB’s main material pyritic land. During long-term laboratory column experiments, significant capacity removing contaminant chemical species was observed. Nevertheless, formation secondary mineral precipitates upon geochemical reactivity within granular media PRB armouring clogging, which diminished rate that is, treatment calcite mainly at entrance zone porous media. Flow properties were altered due blockage pores; instance, hydraulic conductivity reduced by 25% inlet zone. Non-homogeneous clogging towards outlet analysed, time-dependent effect on longevity studied quantified.