Sources of Nitrate and Bromide ContaminantsinGroundwater ofthe Alluvial Aquifer of Arak, Iran

Abstract

The present study investigated <em>NO3^-</em> and <em>Br^-</em>contamination in groundwater of Arak aquifer, Markazi province, Iran. Correlation and factor analyzes were used to detecti nterrelations and sources of <em>NO3^-</em> and <em>Br^-</em>ion concentration and other physicochemical variables. No correlation was observed between <em>NO3^-</em> and otherscontents, but a positive correlation was identified between <em>Br^-</em>and other majorvariables such as EC, TDS, <em>Cl^-</em> and <em>SO4^2-</em>in the groundwater.The results showed that groundwater samples of two areas of Arak aquifer were severely contaminated by <em>NO3</em>^- (up to 50 mg/L) and <em>Br</em>^-(up to 0.5mg/L),which exceededthe WHO and EU provision alguideline values. Nitrate showed an anthropogenic source that originated from sewage water from domestic and industrial activities. Bromide originated from palaeo-salty water of Mighan Lake with a geogenic source.