Highly charged swelling mica-type clays for selective Cu exchange

Environ Sci Technol. 2008 Jan 1;42(1):113-8. doi: 10.1021/es070854k.

Abstract

There is a need to develop highly CU2+ selective materials which can potentially remediate copper contaminated soils and water. Here we show that several highly charged synthetic swelling mica-type clays are highly selective for copper exchange. The synthetic micas have cation exchange capacities (CECs), which are close to their theoretical values. Both Na-saturated and Mg-saturated micas were investigated for Cu ion exchange selectivity. Ion exchange isotherms and Kielland plots were constructed using the equilibrated solution analyses. From these studies it was found that Na-4-mica and Na-3-mica could selectively exchange copper at lower concentrations from solution, whereas Na-2-mica sample performed better by showing Cu ion exchange selectively to almost its capacity. The EPR spectra of Cu-exchanged micas coincide with the mica's charge characteristics that predict increased binding strength of exchangeable Cu in Na-4-mica and Na-3-mica than in Na-2-mica.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Aluminum Silicates / chemistry*
  • Clay
  • Copper / chemistry*
  • Fluorides / chemistry
  • Ion Exchange
  • Kaolin / chemistry
  • Magnesium Chloride / chemistry
  • Magnesium Compounds / chemistry
  • Silica Gel
  • Silicon Dioxide / chemistry
  • Sodium Chloride / chemistry
  • Soil Pollutants / chemistry*
  • Waste Management / methods

Substances

  • Aluminum Silicates
  • Magnesium Compounds
  • Soil Pollutants
  • Magnesium Chloride
  • Kaolin
  • Sodium Chloride
  • magnesium fluoride
  • Silica Gel
  • Silicon Dioxide
  • Copper
  • Fluorides
  • Clay
  • mica