Advanced

Two-stage anaerobic digestion enables heavy metal removal.

Selling, Robert; Håkansson, Torbjörn LU and Björnsson, Lovisa LU (2008) In Water Science and Technology 57(4). p.553-558
Abstract
To fully exploit the environmental benefits of the biogas process, the digestate should be recycled as biofertiliser to agriculture. This practice can however be jeopardized by the presence of unwanted compounds such as heavy metals in the digestate. By using two-stage digestion, where the first stage includes hydrolysis/acidification and liquefaction of the substrate, heavy metals can be transferred to the leachate. From the leachate, metals can then be removed by adsorption. In this study, up to 70% of the Ni, 40% of the Zn and 25% of the Cd present in maize was removed when the leachate from hydrolysis was circulated over a macroporous polyacrylamide column for 6 days. For Cu and Pb, the mobilization in the hydrolytic stage was lower... (More)
To fully exploit the environmental benefits of the biogas process, the digestate should be recycled as biofertiliser to agriculture. This practice can however be jeopardized by the presence of unwanted compounds such as heavy metals in the digestate. By using two-stage digestion, where the first stage includes hydrolysis/acidification and liquefaction of the substrate, heavy metals can be transferred to the leachate. From the leachate, metals can then be removed by adsorption. In this study, up to 70% of the Ni, 40% of the Zn and 25% of the Cd present in maize was removed when the leachate from hydrolysis was circulated over a macroporous polyacrylamide column for 6 days. For Cu and Pb, the mobilization in the hydrolytic stage was lower which resulted in a low removal. A more efficient two-stage process with improved substrate hydrolysis would give lower pH and/or longer periods with low pH in the hydrolytic stage. This is likely to increase metal mobilisation, and would open up for an excellent opportunity of heavy metal removal. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
iminodiacetate, cryogel, anaerobic digestion, metal chelate
in
Water Science and Technology
volume
57
issue
4
pages
553 - 558
publisher
IWA Publishing
external identifiers
  • pmid:18359995
  • wos:000254530000014
  • scopus:42549128248
ISSN
0273-1223
DOI
10.2166/wst.2008.054
language
English
LU publication?
yes
id
3b88f7c9-215d-4343-aa06-b5551a49a962 (old id 1052234)
date added to LUP
2008-07-01 12:52:11
date last changed
2017-07-09 03:49:51
@article{3b88f7c9-215d-4343-aa06-b5551a49a962,
  abstract     = {To fully exploit the environmental benefits of the biogas process, the digestate should be recycled as biofertiliser to agriculture. This practice can however be jeopardized by the presence of unwanted compounds such as heavy metals in the digestate. By using two-stage digestion, where the first stage includes hydrolysis/acidification and liquefaction of the substrate, heavy metals can be transferred to the leachate. From the leachate, metals can then be removed by adsorption. In this study, up to 70% of the Ni, 40% of the Zn and 25% of the Cd present in maize was removed when the leachate from hydrolysis was circulated over a macroporous polyacrylamide column for 6 days. For Cu and Pb, the mobilization in the hydrolytic stage was lower which resulted in a low removal. A more efficient two-stage process with improved substrate hydrolysis would give lower pH and/or longer periods with low pH in the hydrolytic stage. This is likely to increase metal mobilisation, and would open up for an excellent opportunity of heavy metal removal.},
  author       = {Selling, Robert and Håkansson, Torbjörn and Björnsson, Lovisa},
  issn         = {0273-1223},
  keyword      = {iminodiacetate,cryogel,anaerobic digestion,metal chelate},
  language     = {eng},
  number       = {4},
  pages        = {553--558},
  publisher    = {IWA Publishing},
  series       = {Water Science and Technology},
  title        = {Two-stage anaerobic digestion enables heavy metal removal.},
  url          = {http://dx.doi.org/10.2166/wst.2008.054},
  volume       = {57},
  year         = {2008},
}