Details

Autor(en) / Beteiligte

• ELLIOTT, H. A
• BROWN, G. A

Titel

Comparative evaluation of NTA and EDTA for extractive decontamination of Pb-polluted soils

Ist Teil von

• Water, air, and soil pollution, 1989-06, Vol.45 (3-4), p.361-369

Ort / Verlag

Dordrecht: Springer

Erscheinungsjahr

1989

Link zum Volltext

Quelle

SpringerLink (Online service)

Beschreibungen/Notizen

• Nitrilotriacetic acid (NTA) and ethylenediamine-tetraacetic acid (EDTA) were compared for their ability to solubilize Pb from a highly-contaminated (Pb sub(T) = 21%) soil collected from a battery recycling facility. For chelant concentrations below 0.04 M (representing a 1:1 chelant-to-Pb sub(T) molar ratio), EDTA released to 30% more Pb than NTA. NTA-to-Pb sub(T) ratios greater than 1:1 reduced Pb recovery because of readsorption of Pb(NTA) sub(2) super(4-) onto positively-charged oxide soil components at pH < 8.5. For the EDTA system, however, complexation completely bound all coordination sites of Pb and EDTA, leaving no functional groups available for surface adsorption. Thus, Pb recovery progressively increased with higher EDTA concentration, although the additional Pb release with each EDTA increment became smaller. For pH < 5 and EDTA/Pb of 2:1, Pb recovery exceeded 90%.