Phosphate recovery from wastewater using engineered superparamagnetic particles modified with layered double hydroxide ion exchangers

  • Autor:

    Drenkova-Tuhtan, A. / Mandel, K. / Paulus, A. / Meyer, C. / Hutter, F. / Gellermann, C. / Sextl, G. / Franzreb, M. / Steinmetz, H. (2013)
  • Quelle:

    Water Research 47 (2013), 15, 5670–5677
  • Datum: 2013

  • Drenkova-Tuhtan, A. / Mandel, K. / Paulus, A. / Meyer, C. / Hutter, F. / Gellermann, C. / Sextl, G. / Franzreb, M. / Steinmetz, H. (2013): „Phosphate recovery from wastewater using engineered superparamagnetic particles modified with layered double hydroxide ion exchangers“. In: Water Research 47 (2013), 15, 5670–5677

Abstract

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An innovative nanocomposite material is proposed for phosphate recovery from waste- water using magnetic assistance. Superparamagnetic microparticles modified with layered double hydroxide (LDH) ion exchangers of various compositions act as phosphate ad- sorbers. Magnetic separation and chemical regeneration of the particles allows their reuse, leading to the successful recovery of phosphate.

Based upon the preliminary screening of different LDH ion exchanger modifications for phosphate selectivity and uptake capacity, MgFeeZr LDH coated magnetic particles were chosen for further characterization and application. The adsorption kinetics of phosphate from municipal wastewater was studied in dependence with particle concentration, con- tact time and pH. Adsorption isotherms were then determined for the selected particle system. Recovery of phosphate and regeneration of the particles was examined via testing a variety of desorption solutions.

Reusability of the particles was demonstrated for 15 adsorption/desorption cycles. Adsorption in the range of 75e97% was achieved in each cycle after 1 h contact time. Phosphate recovery and enrichment was possible through repetitive application of the desorption solution. Finally, a pilot scale experiment was carried out by treating 125 L of wastewater with the particles in five subsequent 25 L batches. Solideliquid separation on this scale was carried out with a high-gradient mag- netic filter (HGMF).