Extraction Potential of Some Chelating Reagents and Mineral Acid (Edta, Nh4aoc And Hcl) On Bio-Available Heavy Metals In Analfisol Of Southeastern Nigeria

Abstract

This paper reports the laboratory evaluation of the extraction abilities of selected reagents used in most laboratories for the removal and recovery of bioavailable heavy metals in benchmark soil (Alfisol) samples. The results of the evaluation showed that 0.1M HCl is very effective in extracting Zn, Cu, Pb and Fe, 1M NH₄OAC, have shown to extract more Fe (171.63 mgkg^-1) than 0.1M HCl (55.15 mgkg^-1) and 1M EDTA (23.23 mgkg^-1). Similarly, 1M EDTA was shown to be effective in extracting Zn, Cu and Fe. Statistically, there is no significant difference in the extraction of Zn and Cu by the three reagents investigated at (P<0.05) probability level. The results of this evaluation showed that those three extracting reagents studied have significant abilities to be effective reagents in the removal and recovery of bio-available heavy metals in an Alfisol characterized by a loamy texture, pH of 5.0 – 6.20 and organic matter content of 3.41% - 3.60%. the total N and available P had values ranging from 0.14 – 0.168% and 56.30 – 77.50 mgkg^-1 respectively which are rated as medium to high in soil fertility class of south-eastern Nigeria.