Source Identification and Evaluation of Elemental Pollution of Surface Sediments in Farahabad Coast, Caspian Sea

Abstract

The study of sediments as one of the reservoirs for absorbing environmental pollutants and especially heavy metals is of particular importance. Therefore, this research was conducted with the aim of identifying and evaluating the contamination of arsenic, cadmium, nickel, and vanadium elements in the sediments of Farahabad coast of the Caspian Sea in 2018. In this study, after collecting 36 sediment samples from 12 selected stations, the values ​​of pH, EC, organic matter, and texture of sediments were determined. The concentrations of elements were determined by inductively coupled plasma optical spectroscopy. In addition, in order to evaluate the pollution of sediments, environmental toxicology criteria were calculated, including indicators of pollution coefficient, enrichment, and pollution load. In order to identify the potential sources of elements and their grouping in the sediment samples, multivariate statistical methods were used, namely principal component analysis and hierarchical clustering. For statistical processing of the results, one-way analysis of variance, one-sample t-test, and Pearson's correlation coefficient were used in the SPSS software. The average concentration of arsenic, cadmium, nickel, and vanadium was 12.7, 0.191, 35.0, and 31.9 mg/kg, respectively. The output results of PCA, HCA models, EF index values, ​​and coefficient of variation, as well as Pearson's correlation matrix, showed that arsenic probably originates from man-made sources and cadmium, nickel, and vanadium elements have natural sources.

Keywords

• caspian sea
• ecotoxicological criteria
• heavy metals
• multivariate statistics
• sediment pollution