3.10 Advantages of using metal oxides and clays for remediation

The use of clay minerals and oxides is more effective than using other materials for remediation of heavy metals from the environment. From example, the use of sepioloite is better for remediation of Cd compared to Ca(OH)2 [119]. In addition, clay minerals and oxides can be recycled and regenerated for additional remediation use. For example, synthetic palygorskite-Fe oxide exhibited the capability of removing Pb and three cycles reusable potential and retains it magnetic properties for the removal of the heavy metals [85]. Recovery of metals from sorbents can increase the life cycle and long term remediation cost [120]. The estimated zinc that will accumulate in composite substrate in Force Crag Mine is will amount to €7600 in 10 years, however, removal of this substrate after its exhaustion will cost more than €0.8 M whereas recycling the substrate through acid washing is estimated to cost €155,000 [120]. Similarly, oxides and clay minerals can be recycled and reused for remediation of the contaminant. In addition, these sorbents can be used to remediate economic heavy/rare earth metals for commercial and industrial purposes, however, this requires further investigation.
