Assessment of Heavy Metals Pollution in Sediments from Reservoirs of the Olt River as Tool for Environmental Risk Management

Mihaela Iordache ,Andreea Maria Iordache ,Claudia Sandru ,Cezara Voica ,Ramona Ionela Zgavarogea ,Marius Gheorghe Miricioiu ,Roxana Elena Ionete

doi:10.37358/rc.19.12.7725

Abstract

Heavy metals are among the most persistent pollutants in the ecosystem due to their resistance at decomposition in natural condition. They have low solubility in water and tend to be adsorbed and accumulated on bottom sediments. Anthropogenic actions conduct to the discharge of heavy metals from various sources (industrial, urban, and/or agriculture) to rivers water that are ultimately immobilized in marine sediments under current action. In this work, an investigation of pollution and ecological risk in the Olt River waters is performed based on assessing the accumulation of heavy metals in sediments. Therefore, sediment samples were collected from 22 locations on the Olt River, in its middle and lower basin, and investigated by inductively coupled plasma mass spectrometry which allows us to measure very low elements concentration levels. Two main aspects were foreseen in this study: (i) determining the content and spatial distribution of heavy metals in the Olt River surface sediments, and (ii) assessing the pollution level based on various parameters, namely the contamination factor, the geo-accumulation, pollution load and Nemerow pollution indexes, the potential ecological risk, and risk assessment code. This methodology proves to be an appropriate tool to apply in decision-making on environmental risk management. Keywords: heavy metals, ecological risk, pollution, ecosystem, sediments

Highlights

Because of industrial growth and development, water environments are increasingly exposed to heavy metal pollutants, which are a serious threat for the aquatic ecosystem, such as water, sediments and biota, because of their environmental persistence, bioaccumulation and ability to be incorporated into the food chain
The total concentration of heavy metals for each sampling site found in sediments of the Olt River are highlight in Fig. 2 and Table 8
In this study, a methodology to assess the pollution with heavy metals (As, Cd, Cr, Cu, Ni, Pb, Hg and Zn) in surface sediment of the Olt River in its middle and lower basin was investigated

Summary

Introduction

Because of industrial growth and development, water environments are increasingly exposed to heavy metal pollutants, which are a serious threat for the aquatic ecosystem, such as water, sediments and biota, because of their environmental persistence, bioaccumulation and ability to be incorporated into the food chain. Heavy metals are distributed among aqueous phase, suspended particles and sediments. Suspended particles plays an important role controlling the reactivity, transport and biological impact of metals and other substances in the aquatic environment and provide a crucial link for chemical constituents between water column, bed sediments and food chain [3]. Heavy metals may accumulate in the aquatic ecosystems, especially in fish tissues, which, in turn, may enter into the human food chain and eventually lead to health risks. Heavy metals and metalloids discharged into an aquatic system by both anthropogenic and natural sources are distributed between different compartments of these ecosystems, such as water, sediment and biota. The lake sediment analysis plays an important role in evaluating pollution status in aquatic environment [9]

Methods

Results

Conclusion