Zinc and copper distribution in soils and their removal by chelating extraction

✍ Scribed by Astrid Barona; Itziar Aranguiz; Ana Elias

• Publisher: Wiley (John Wiley & Sons)
• Year: 1999
• Tongue: English
• Weight: 334 KB
• Volume: 74
• Category: Article
• ISSN: 0268-2575
• DOI: 10.1002/(sici)1097-4660(199907)74:7<700::aid-jctb103>3.0.co;2-f

✦ Synopsis

The addition of chelates to soils can increase metal transport from the solid to the aqueous phase and consequently increase metal mobility. This research evaluated the effects of chemical associations of zinc and copper on extraction with DTPA (diethylenetriamine-pentacetic acid) in soils. Soil samples were fractionated into exchangeable, carbonate, oxide, organic and residual fractions and they were extracted with DTPA. The residual fraction varied from 22 to 73% for zinc and from 34 to 94% for copper. In the most contaminated site, as much as 61% of the zinc was associated with oxides. DTPA-extractable amounts were up to 33% for zinc and up to 56% for copper. Principal component analysis revealed the in¯uence of soil texture on DTPA extraction ef®ciency. Multiple regression analysis revealed that the best extraction rate will be obtained when the soil clay silt percentage is low and when the metal content in the organically bound and oxide-bound fractions is signi®cant.