https://search.dev.ndltd.org/etd/massey/oai:mro.massey.ac.nz:10179/12283
type: CreativeWork
name: The economic significance of the phytoextraction of nickel, cobalt and gold from metalliferous soils : a thesis in partial fulfilment of the requirements for the degree of Master of Science at Massey University
description: Phytoextraction of heavy metals is a relatively new technology that has potential applications for the remediation of many contaminated sites around the world. The technology has significant applications in the minerals industry for the treatment of low-grade ores and metalliferous mine waste. This study concerns the investigation of the potential to remove heavy metals, in particular nickel, cobalt and gold, from artificial and lateritic substrates. Four experiments comprise this study of the phytoextraction of nickel, cobalt and gold using both accumulator and non-accumulator species. Nickel and cobalt bioavailability was determined by ammonium acetate extraction for both artificial and laterite substrates. It was found that ammonium acetate extractability was predictive for nickel accumulation from a nickel-only artificial substrate. Cobalt bioavailability did not predict the accumulation response of either Alyssum bertolonii or Berkheya coddii grown of artificial substrates. The potential for phytoextraction of nickel and cobalt was investigated using the known nickel hyperaccumulators A. bertolonii and B. coddii, grown on artificially prepared substrates. The substrates were nickel-only (4 mg/kg to 1000 mg/kg), cobalt-only (4 mg/kg to 1000 mg/kg) and nickel-cobalt mixed (1:1 ratio, 4 mg/kg to 500 mg/kg) amendments of sulphates to commercial potting mix. Hyperaccumulation from nickel-only and cobalt-only substrates resulted in typical logarithmic metal uptake by both species. The cobalt-only substrates were phytotoxic to B. coddii above a concentration of 15-20 mg/kg. Phytotoxicity significantly reduced biomass production in B. coddii without effecting the bioaccumulation coefficient. No corresponding cobalt phytotoxicity was observed in A. bertolonii over the experimental range, although biomass production appears to favour substrate concentrations below 30 mg/kg. The bioavailability and hyperaccumulation of cobalt from the mixed nickel-cobalt substrates dramat…
abstract: Phytoextraction of heavy metals is a relatively new technology that has potential applications for the remediation of many contaminated sites around the world. The technology has significant applications in the minerals industry for the treatment of low-grade ores and metalliferous mine waste. This study concerns the investigation of the potential to remove heavy metals, in particular nickel, cobalt and gold, from artificial and lateritic substrates. Four experiments comprise this study of the phytoextraction of nickel, cobalt and gold using both accumulator and non-accumulator species. Nickel and cobalt bioavailability was determined by ammonium acetate extraction for both artificial and laterite substrates. It was found that ammonium acetate extractability was predictive for nickel accumulation from a nickel-only artificial substrate. Cobalt bioavailability did not predict the accumulation response of either Alyssum bertolonii or Berkheya coddii grown of artificial substrates. The potential for phytoextraction of nickel and cobalt was investigated using the known nickel hyperaccumulators A. bertolonii and B. coddii, grown on artificially prepared substrates. The substrates were nickel-only (4 mg/kg to 1000 mg/kg), cobalt-only (4 mg/kg to 1000 mg/kg) and nickel-cobalt mixed (1:1 ratio, 4 mg/kg to 500 mg/kg) amendments of sulphates to commercial potting mix. Hyperaccumulation from nickel-only and cobalt-only substrates resulted in typical logarithmic metal uptake by both species. The cobalt-only substrates were phytotoxic to B. coddii above a concentration of 15-20 mg/kg. Phytotoxicity significantly reduced biomass production in B. coddii without effecting the bioaccumulation coefficient. No corresponding cobalt phytotoxicity was observed in A. bertolonii over the experimental range, although biomass production appears to favour substrate concentrations below 30 mg/kg. The bioavailability and hyperaccumulation of cobalt from the mixed nickel-cobalt substrates dramat…
author: Keeling, Scott M
keywords: Hyperaccumulator plants, Economic aspects, Bioavailability, Metals, Plants, Effect of heavy metals on
date published: 2000
date modified: 2026-07-27T20:17:56Z
provider: Massey University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Massey University