The addition of organic carbon and nitrate affects reactive transport of heavy metals in sandy aquifers

Yamini Satyawali, Piet Seuntjens, Sandra Van Roy, Ingeborg Joris, Silvia Vangeel, Winnie Dejonghe, Karolien Vanbroekhoven

Research output: Contribution to journalArticlepeer-review

5 Scopus citations

Abstract

Organic carbon introduction in the soil to initiate remedial measures, nitrate infiltration due to agricultural practices or sulphate intrusion owing to industrial usage can influence the redox conditions and pH, thus affecting the mobility of heavy metals in soil and groundwater. This study reports the fate of Zn and Cd in sandy aquifers under a variety of plausible in-situ redox conditions that were induced by introduction of carbon and various electron acceptors in column experiments. Up to 100% Zn and Cd removal (from the liquid phase) was observed in all the four columns, however the mechanisms were different. Metal removal in column K1 (containing sulphate), was attributed to biological sulphate reduction and subsequent metal precipitation (as sulphides). In the presence of both nitrate and sulphate (K2), the former dominated the process, precipitating the heavy metals as hydroxides and/or carbonates. In the presence of sulphate, nitrate and supplemental iron (Fe(OH)3) (K3), metal removal was also due to precipitation as hydroxides and/or carbonates. In abiotic column, K4, (with supplemental iron (Fe(OH)3), but no nitrate), cation exchange with soil led to metal removal. The results obtained were modeled using the reactive transport model PHREEQC-2 to elucidate governing processes and to evaluate scenarios of organic carbon, sulphate and nitrate inputs. © 2010 Elsevier B.V.
Original languageEnglish (US)
Pages (from-to)83-93
Number of pages11
JournalJournal of Contaminant Hydrology
Volume123
Issue number3-4
DOIs
StatePublished - Apr 2011
Externally publishedYes

Fingerprint

Dive into the research topics of 'The addition of organic carbon and nitrate affects reactive transport of heavy metals in sandy aquifers'. Together they form a unique fingerprint.

Cite this