Assessment of trace element contamination in sediments of the Madhumati River using Neutron Activation Analysis

Abstract

In this study, concentrations of 23 major and trace elements in soil samples collected from 12 locations of the Madhumati river, Gopalgonj were determined to study spatial distributions and contamination status of the elements in the sediments of the river. In carrying out the analysis, TRIGA Mark-II research reactor based Neutron Activation Analysis (NAA) was adopted due to its versatile applicability and high sensitivity. In this study, quality of the analyses was evaluated by analyzing certified reference materials IAEA-SL-1 (lake sediment) and NIST-1633b (coal fly ash) relative to IAEA-Soil-7. Elemental contamination assessments were done by the environmental indices such as contamination factor (CF), pollution load index (PLI), geo-accumulation index (Igeo), enrichment factors(EF) and the inter-element correlation analysis. When compared with upper continental crustal (UCC) average values, it is observed that mean concentrations of Al, K, Sc, Ti, Fe, Zn, As, Rb, Cs, Ce, Tb, Dy, Hf, U and Th show elevated values with respect to UCC values. The enrichment factor (EF) values of the environmentally toxic elements As and Th (EF =1.5- 3.0) at most of the sampling points indicate that Madhumati river sediments are minorly enriched with these two elements. According to I_geo values_, As, Rb, and Th in river sediments are uncontaminated to moderately contaminated (0<I_geo<1). The Madhumati river sediment is practically uncontaminated by rest of elements. In this study, the calculated pollution load index (PLI) values among the sampling points vary from 0.461–1.29 which indicates the progressive deterioration of the sediment quality of the river. The Pearson Correlation matrix analysis is also used to explore the associations among the studied elements. Since there is no literature data available on elemental concentration of the sediments of the Madhumati river, this study will be used as baseline data for future contamination study of this river.  

• Supervision