Chelating extraction technology in removing and recovering heavy metals from municipal sludge

  • 1 Institute of Environment and Ecology, Agriculture Academy of Vytautas Magnus University, Lithuania


Comparable heavy metal extraction efficiency using different chelating aminopolycarboxylic acids was studied with sewage sludge as well as sludge-soil mixtures. EDDS and MGDA showed only slightly lower extraction efficiency in comparison with EDTA, at solution pH 6 and 25°C. Chemical fractions of HM in the sludge were determined using sequential extraction. According to their stability in the environment (in sulphide and residual fractions) the investigated heavy metals can be ranked as follows: Cr> Pb> Ni> Cd> Zn ≈ Cu. It was found out that methylglycinediacetic and S,S’-ethylenediaminedisuccinic acids had much better biological degradation properties than widely for metal complexation used ethylenediaminetetraacetic acid – EDTA. Possibility to utilize metal-contaminated extraction solution by chelant recovery with calcium hydrosilicate was also investigated.



  1. Emmerich, W. E., Lund, J. L., Page, A. L. and Chang, A. C. (1982). Solid phase form of heavy metal in sewage sludge in sewage sludge treated soils. Journal of Environmental Quality. 11, pp. 178–181.
  2. Environmental, economic and social impacts of the use of sewage sludge on land. (2010). Final Report. Part III: Project Interim Reports. This report has been prepared by Milieu Ltd, WRc and RPA for the European Commission, DG Environment under Study Contract DG ENV.G.4/ETU/2008/0076r. (Source:
  3. Ministry of Environment of the Republic of Lithuania (2001). Normatyvinis dokumentas LAND 20-2005 „Nuotėkų dumblo naudojimo tręšimui reikalavimai“ [Lithuanian Environmental Regulatory Document LAND 20-2005 “Rules for the sewage sludge uses for agricultural and land reclamation purposes”]. The recent version is valid from 2016-08-01. No 61-2196. In Lithuanian. Latest access 2018-04-03 at:
  4. Praspaliauskas, M., Pedišius, N. (2017). A review of sludge characteristics in Lithuania's wastewater treatment plants and perspectives of its usage in thermal processes Renewable and Sustainable Energy Reviews 67:899-907.
  5. Zaleckas, E., Paulauskas, V., Dainiene, R. (2007). Extraction of Cu from Sewage Sludge using Organic Acids // Rural development 2007. Kaunas-Akademija, 252-256.
  6. Wang, C., Hu, X., Chen. M. L., Wu, Y. H. (2005). Total concentrations and fractions of Cd, Cr, Pb, Cu, Ni and Zn in sewage sludge from municipal and industrial wastewater treatment plants. Journal of Hazardous Materials. B119:245–249
  7. Wei, Y., Liu, Y. (2005). Effects of sewage sludge compost application on crops and cropland in a 3-year field study. Chemosphere 59 (9):1257–1265.

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