Volume 1, Issue 2 — Year 2024 — Article e100017

Batoul Hassanzadeh¹; Ahmad Abbasnejad²

1. Department of Geology, Shahid Bahonar University of Kerman, Kerman 7616913439, Iran
2. Department of Geology, Shahid Bahonar University of Kerman, Kerman 7616913439, Iran

The Noug Plain, covering an area of approximately 3,600 km2, is located in the southeast of Iran, in the western part of Kerman province. Its geographical coordinates range from 29°23\' to 31°24\' North latitude and from 54°10\' to 57°34\' East longitude. Given that arsenic concentrations are high in certain areas of neighboring plains (Anar and Rafsanjan), this plain was chosen to assess the variations in arsenic concentration. To this end, samples were collected from 23 scattered observation wells across the plain, and arsenic concentration, along with major ions and some other elements, were determined using ICP-MS. Isoconcentration maps and statistical analyses (Principal Component Analysis and Cluster Analysis) were performed on these samples. Arsenic concentrations in the plain range from 0.5 to 135.9 parts per million, with an average of 20.1 ppb, which exceeds the drinking water standard of 10 ppb. Based on this study, it appears that the source of arsenic is the Miocene red conglomerates and geothermal waters resulting from the alteration of Jurassic shales. The direct correlation between arsenic and pH suggests a role of adsorption in the release of arsenic from iron oxide surfaces. Additionally, arsenic decreases slightly toward the northwest with increasing dissolved salts in the groundwater, likely due to its minor absorption and entry into the crystalline network of aragonite, which precipitates in the northwest as evaporation increases and concentrations rise.

Arsenic contamination, Groundwater, Geothermal waters, Environmental factors, Geochemical analysis