Heavy metal distribution in sediment

Project Abstract

Heavy metal contamination in sediments is a significant environmental concern due to its potential adverse effects on aquatic ecosystems and human health. This study aimed to investigate the distribution of heavy metals in sediment samples collected from a freshwater lake. The sediment samples were analyzed for the concentrations of key heavy metals including lead (Pb), cadmium (Cd), copper (Cu), and zinc (Zn) using atomic absorption spectrophotometry. The results revealed varying levels of heavy metal contamination across different sampling sites within the lake. The highest concentrations of Pb, Cd, Cu, and Zn were found in sediments collected near the industrial discharge point, indicating a clear influence of anthropogenic activities on heavy metal accumulation in the lake sediments. Spatial mapping of heavy metal distribution showed localized hotspots of contamination, highlighting the need for targeted remediation efforts in these areas. Furthermore, the study investigated the potential mobility and bioavailability of heavy metals in sediments using sequential extraction techniques. The results indicated that a significant portion of the total metal content was associated with the potentially mobile fractions, suggesting the risk of metal release into the water column under changing environmental conditions. In addition, the study assessed the ecological risks associated with heavy metal contamination in the sediments using established risk assessment models. The results indicated that certain sampling sites exceeded the threshold values for ecological risk, indicating potential harm to benthic organisms and overall ecosystem health. These findings underscore the importance of continuous monitoring and management of heavy metal contamination in aquatic sediments to mitigate environmental risks. Overall, this study provides valuable insights into the distribution, mobility, and ecological risks of heavy metals in freshwater lake sediments. The findings highlight the need for effective management strategies to control heavy metal pollution and protect aquatic ecosystems. Future research efforts should focus on long-term monitoring of heavy metal levels in sediments, as well as the development of remediation techniques to reduce the impact of contamination on environmental and human health.

Project Overview

<p> </p><div><p><strong>1.1 INTRODUCTION</strong></p><p>Heavy metals pollution of aquatic ecosystem is becoming a potential global problem, pollution typically refers to chemicals or other substance in concentration greater than it would occur under natural conditions. Water pollution is the introduction by man of substances into the aquatic environment resulting from deleterious effect as harm to human health (FAO 1990).The presence of increased level of heavy metals in the aquatic environment has been of much concern for the past decades due to adverse effect of some metals on living organisms in food chains leading to man. Pollutants are the cause of major water quality degradation around the world. Several toxic metals which are important to the environment and human health have been detected in aquatic media. These toxic metals include the non-essential meals and are no importance to humans (Borgman and Norwood 2002).</p><p>&nbsp; &nbsp; Trace amount of heavy metals are always present in fresh water from terrigenous sources &nbsp; such as weathering of rocks resulting into geo-chemical recycling of heavy metal elements in these ecosystem. Trace elements may be immobilised within the stream sediments and could be involved in absorption, co-precipitation and complex formation. Sometimes they are co-adsorbed with other elements as oxides, hydroxides of Fe, Mn, or may occur in particulate form.</p><p>&nbsp; &nbsp; &nbsp; Heavy metal may enter into aquatic ecosystem from anthropogenic sources, such as industrial wastewater discharge, sewage wastewater, fossil fuel combustion, and atmospheric deposition. Trace element in stream sediment compartment can be used to reveal the history and intensity of local and regional pollution. In this work, the of stream sediment contamination was assess using geo-accumulation index.</p><p><strong>1.2 AIMS AND OBJECTIVES</strong></p><p>The main objectives of the current study area are:</p><ol><li>To assess the extent and degree of metals, and the origin of these metals, using the geo-accumulation index of the metals.</li><li>To determine the total content of heavy metals in surface sediments of Akpabuyo.</li><li>To estimate the anthropogenic input and to assess the pollution status on the area.</li></ol><p>1.3 STUDY AREA</p><p>The study area which is located in Akpabuyo, Cross River State &nbsp;lies between longitudes 80 22I &nbsp;30II E – 80 &nbsp;30I 0II E and latitude 40 52I 30II N – 40 57I 30II N (fig 2). &nbsp;With an area of 126,4032 Square Km. Although many stream samples where collected but few was selscted for the heavy metal analysis. The various Locations in Akpabuyo which sediment samples were collected and used to carry out the analysis are Esuk Mbat stream(L1), Esuk Ekpo Eyo Stream(L2), Ikot Akwa Stream(L3), Dan Archibong Stream(L4), Itu Stream(L5), Ikot Ndarake Stream(L6), Asioha Stream(L7), Ikot Ekpo Ene Stream(L8), Ekpene Ikot Imo Stream(L9), Ikot Nakanda(L10), and their following coordinate shown respectively (table 1.3) . It originate from a hilly region and flows through several villages and farmland</p><p></p></div><h3></h3><br> <br><p></p>