3 results for Anderson, C. W. N.

  • The Induced Accumulation Of Gold In The Plants Brassica juncea, Berkheya coddii and Chicory

    Lamb, A. E.; Anderson, C. W. N.; Haverkamp, R. G. (2001-09-01)

    Journal article
    Massey University

    In this study the growth stubstrate of the plants Brassica juncea, Berkheya coddii and chicory were amended with thiocyanate and cyanide solutions to induce uptake and the gold concentrations in the different organs determined. Both species showed maximum uptake with cyanide amendment although thiocyanate also induced hyperaccumulation. Gold concentrations ranged from negligible in the leaves of B. coddii amended with thiocyanate, to 326 mg Au/kg dried biomass in the leaves of B. juncea amended with cyanide. The chemical additives KI, KBr, NaS2O3 were also used with the B. juncea and chicory. The results showed varying degrees of hyperaccumulation with all chemical treatments. Cyanide again gave the best results with 164 mg Au/kg dried biomass measured in the chicory plant. NaS2O3, KI and NaSCN gave maximum results of 51, 41 and 31 mg Au/kg dried biomass respectively. This technology has potential application in the economic recovery of metals.

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  • The Extraction Of Gold From Plants And Its Application To Phytomining

    Lamb, A. E.; Anderson, C. W. N.; Haverkamp, Richard G. (2001-09-01)

    Journal article
    Massey University

    Phytomining is the use of hyperaccumulating plants to extract a metal from soil with recovery of the metal from the biomass to return an economic profit. This work looks at the possible methods for recovering gold from plant material, including chemical reduction with and without solvent extraction, thermal reduction and copper electrodeposition. Some progress was made with ascorbic acid as the chemical reductant. A solid phase was produced at the liquid-liquid interface after solvent extraction. The deposition reaction reduced the gold concentration in methyl isobutyl ketone (MIBK) to less than 2 ppm, equating to 85% recovery, in 3.5 hours. Copper electrodeposition also gave some promising results. However, both require much more work before they are viable for scale-up.

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  • Closing the loop: biosolids to rebuild degraded soils

    Robinson, B.; Clucas, L. M.; Anderson, C. W. N.; Knowles, O.; Gartler, J.; Portmann, D.; Contangelo, A.; Marmiroli, M.

    Conference Contribution - Published
    Lincoln University

    Biosolids represent a valuable source of soil nutrients and zinc, a trace element that is deficient in many areas. Yet environmental concerns, particularly regarding nitrate leaching, limit the application of biosolids to soil. Biochar, a form of charcoal that is added to soil, is a potential solution. We aimed to determine the effect of biosolids and biochar addition to the uptake of Zn by crop plants and investigate the effects of biochar addition on Zn uptake and nitrate leaching from biosolids amended soil. We tested 10 common crop plants as well as pasture in a pot trial with and without the addition of biosolids and biochar. The effect of biochar on the nitrate leaching from biosolids amended soil was measured in a lysimeter experiment. There were large species differences in Zn uptake from the biosolids and biochar amended soils. Beetroot (Beta vulgaris) and spinach (Spinacia oleracea) showed the greatest increases are good candidates for further biofortification research. Over a five-month period, biochar reduced the nitrate leaching from a biosolids amended soil to levels below an unamended soil. Future work will focus on the performance of the system over the long-term.

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