Highly charged swelling mica-type clays for selective Cu exchange.
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.
Ravella
Ramesh
R
Department of Crop and Soil Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Komarneni
Sridhar
S
Martinez
Carmen Enid
CE
D000538:Aluminum Silicates / Q000737:chemistry*; D000077215:Clay; D003300:Copper / Q000737:chemistry*; D005459:Fluorides / Q000737:chemistry; D007474:Ion Exchange; D007616:Kaolin / Q000737:chemistry; D015636:Magnesium Chloride / Q000737:chemistry; D017616:Magnesium Compounds / Q000737:chemistry; D058428:Silica Gel; D012822:Silicon Dioxide / Q000737:chemistry; D012965:Sodium Chloride / Q000737:chemistry; D012989:Soil Pollutants / Q000737:chemistry*; D018505:Waste Management / Q000379:methods
D000538:Aluminum Silicates; D017616:Magnesium Compounds; D012989:Soil Pollutants; D015636:Magnesium Chloride; D007616:Kaolin; D012965:Sodium Chloride; C031288:magnesium fluoride; D058428:Silica Gel; D012822:Silicon Dioxide; D003300:Copper; D005459:Fluorides; D000077215:Clay; C011934:mica