sources of nitrate and bromide contaminants of groundwater in alluvial aquifer of arak, iran

the present study investigated no3- and br- contamination in groundwater of arak aquifer of markazi province. correlation and factor analysis were used to detect interrelation and sources of concentration of no3- and br- ions and others physicochemical variables. no correlation was observed between no3- and others contents, but positive correlation was identified between br- with other major variables such as ec, tds, cl- and so42- in the groundwater. the resulted data indicated that groundwater samples of two areas of arak aquifer were severely contaminated with no3- (up to 50 mg/l) and br- (up to 0.5mg/l),which were exceeded the who and eu provisional guideline values. nitrate was shown anthropogenic source and originated from sewage water from domestic and industrial activities. bromide was originated from palaeo-salt water of mighan lake and has geogenic source.