WATER QUALITY ASSESSMENT AND GEOCHEMICAL PROCESSES IN THE UNCONFINED COASTAL BOA VIAGEM AQUIFER, RECIFE, NE BRAZIL
A hydrochemical study was conducted on the Quaternary Aquifer, in Recife, Brazil. Groundwater samples were collected in March–April 2015, at the beginning of the rainy season. Conventional graphics, ionic ratios, saturation indices, GIS mapping, and geostatistical and multivariate statistical analyses were used to water quality assessment and to characterize the main hydrochemical processes controlling groundwater’s chemistry. Q-mode hierarchical cluster analysis separated the samples into three clusters and five sub-clusters according to their hydrochemical similarities and facies. Principal Component Analysis (PCA) was employed to the studied groundwater samples where a three-factor model explains 80% of the total variation within the dataset. The PCA results revealed the influence of seawater intrusion, water-rock interaction, and nitrate contamination. The physico-chemical parameters of ~30% groundwaters exceed the World Health Organization (WHO) guidelines for drinking water quality. Nitrate was found at a concentration >10 mg NO3−/L in ~21% of the wells and exceeded WHO reference values in one. The integrated approach indicates the occurrence of the main major hydrogeochemical processes occurring in the shallow marine to alluvial aquifer as follow: 1) progressive freshening of remaining paleo-seawater accompanying cation exchange on fine sediments, 2) water-rock interaction (i.e., dissolution of silicates), and 3) point and diffuse wastewater contamination, and sulfate dissolution. This study successfully highlights the use of classical geochemical methods, GIS techniques, and multivariate statistical analyses (hierarchical cluster and principal component analyses) as complementary tools to understand hydrogeochemical processes and their influence on groundwater quality status to management actions, which could be used in similar alluvial coastal aquifers.
How to Cite
Copyright (c) 2021 Geochimica Brasiliensis
This work is licensed under a Creative Commons Attribution 4.0 International License.
Copyright Transfer Statement
The copyright to this article is transferred to Sociedade Brasileira de Geoquímica effective if and when the article is accepted for publication. The author(s) warrant(s) that his/her/their contribution is original and that he/she/they has/have full power to make this grant. The author(s) sign(s) for and accept(s) responsibility for releasing this material The copyright transfer covers the exclusive right and license to reproduce, publish, distribute and archive the article in all forms and media of expression now known or developed in the future, including reprints, translations, photographic reproductions, electronic form (offline, online) or any other reproductions of similar nature.
Author(s) may self-archive an author-created version of his/her/their submitted version, accepted version and final published article on his/her/their own website and or in his/her/their institutional repository. He/she/they may also deposit this version on his/her/their funder’s or funder’s designated repository at the funder’s request or as a result of a legal obligation.
The author(s) retain(s) the right to use his/her/their submitted version, accepted version and final published article for his/her/their further scientific career by including the final article published by Geochimica Brasiliensis in other publications such as dissertations, theses and postdoctoral qualifications provided acknowledgement is given to the original source of publication.
After submission of the agreement signed by the corresponding author(s), changes of authorship or in the order of the authors listed will not be accepted by Sociedade Brasileira de Geoquímica.
Title of article:
Place and Date: