Removal of Arsenate in Acid Mine Drainag

Immobilization of arsenate in groundwater impacted by acid mine drainage was investigated using a permeable reactive barrier (PRB) column bearing granulated blast furnace slag (GBFS) to compare with iron granules which are commonly used. The study aimed to assess the sorption capacity of arsenate onto GBFS and its performance in reducing arsenate concentrations. Laboratory column experiments were conducted to measure the removal efficiency of both materials. Results indicated that 15 mg/L of arsenate was decreased to less than 0.4 mg/L for more than 18 pore volumes (pv) in the GBFS-PRB and less than 0.04 mg/L for more than 17 pv in the iron bearing PRB. The reduction was attributed to sorption, co-precipitation, and the formation of hydrated calcium arsenate. The GBFS demonstrated advantages such as higher porosity and lower density, which facilitate industrial handling and suggest its potential as an alternative reactive material in PRBs for the immobilization of arsenic and manganese in acid mine drainage. The study concludes that GBFS can serve as an effective and sustainable material in groundwater remediation applications.