Nickel removal from nickel plating waste water using a biologically active moving-bed sand filter

Research output: Contribution to journalArticle

Authors

Colleges, School and Institutes

Abstract

Efficient removal of dissolved nickel was observed in a biologically active moving-bed 'MERESAFIN' sand filter treating rinsing water from an electroless nickel plating plant. Although nickel is fully soluble in this waste water, its passage through the sand filter promoted rapid removal of approximately 1 mg Ni/l. The speciation of Ni in the waste water was modelled; the most probable precipitates forming under the conditions in the filter were predicted using PHREEQC. Analyses of the Ni-containing biosludge using chemical, electron microscopical and X-ray spectroscopic techniques confirmed crystallisation of nickel phosphate as arupite (Ni3(PO4)2 x 8H2O), together with hydroxyapatite within the bacterial biofilm on the filter sand grains. Biosorption contributed less than 1% of the overall sequestered nickel. Metabolising bacteria are essential for the process; the definitive role of specific components of the mixed population is undefined but the increase in pH promoted by metabolic activity of some microbial components is likely to promote nickel desolubilisation by others.

Details

Original languageEnglish
Pages (from-to)567-581
Number of pages15
JournalBiometals
Volume16
Publication statusPublished - 1 Jan 2004

Keywords

  • biofilm, sand filter, bioprecipitation, nickel, galvanic waste water