Major hydrogeochemical processes in an Acid Mine Drainage affected estuary

Maria P. Asta*, Maria L. Calleja, Rafael Pérez-López, Luis F. Auqué

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

26 Scopus citations


This study provides geochemical data with the aim of identifying and quantifying the main processes occurring in an Acid Mine Drainage (AMD) affected estuary. With that purpose, water samples of the Huelva estuary were collected during a tidal half-cycle and ion-ion plots and geochemical modeling were performed to obtain a general conceptual model. Modeling results indicated that the main processes responsible for the hydrochemical evolution of the waters are: (i) the mixing of acid fluvial water with alkaline ocean water; (ii) precipitation of Fe oxyhydroxysulfates (schwertmannite) and hydroxides (ferrihydrite); (iii) precipitation of Al hydroxysulfates (jurbanite) and hydroxides (amorphous Al(OH)3); (iv) dissolution of calcite; and (v) dissolution of gypsum. All these processes, thermodynamically feasible in the light of their calculated saturation states, were quantified by mass-balance calculations and validated by reaction-path calculations. In addition, sorption processes were deduced by the non-conservative behavior of some elements (e.g., Cu and Zn).

Original languageEnglish (US)
Pages (from-to)295-305
Number of pages11
JournalMarine pollution bulletin
Issue number1
StatePublished - Feb 15 2015
Externally publishedYes


  • Acid water
  • Geochemical modeling
  • Huelva estuary
  • Hydrochemistry
  • Mixing
  • Ocean water

ASJC Scopus subject areas

  • Oceanography
  • Aquatic Science
  • Pollution


Dive into the research topics of 'Major hydrogeochemical processes in an Acid Mine Drainage affected estuary'. Together they form a unique fingerprint.

Cite this