Journal Article

Effect of pH, Sulphate Concentration and Total Organic Carbon on Mercury Accumulation in Sediments in the Volta Lake at Yeji, Ghana

Kwaansa-Ansah, E. E., Ephraim, J. H., Adimado, A. A., Voegborlo, R. B., Nriagu, J. O.

2012

Overview

In this study, pH, total organic carbon, sulphate concentration and mercury concentrations of sediment samples from the Volta Lake at Yeji in the northern part of Ghana were determined. The results indicate that pH ranged from 6.32 to 8.21, total organic carbon ranged from 0.17 to 3.02 g/kg and sulphate concentration from 10.00 to 57.51 mg/kg. Total mercury concentrations ranged from 32.61 to 700 ng/g which is below the International Atomic Energy Agency recommended value of 810 ng/g. Humic substance-bound mercury ranged from 81.15 to 481.31 mg/kg in sediments and its two fractions existed as humic acid-bound mercury > fulvic acid-bound mercury with the ratio of humic substance-bound mercury to fulvic acid-bound mercury as 1.62 on the average. Humic substance-bound mercury and the two fractions fulvic acid-bound mercury and humic substance-bound mercury in sediments were favorably determined and found to correlate significantly positive with total organic carbon (r = 0.538) and total mercury (r = 0.574). However, there were poor correlations between SO 4 2− concentrations and humic substance-bound mercury (r = −0.391) as well as the two fractions; fulvic acid (r = −0.406) and humic acid (r = −0.381). By assuming that methyl mercury is mostly formed in sediments, these significant relations suggest that the efficiency of mercury being methylated from a given inorganic form depends on the amount, and most likely biochemical composition of total organic carbon in the lake sediment but not the SO 4 2− concentration.

• Publisher: Springer-Verlag,Springer Nature B.V
• Subject: Acidity / analysis / Aquatic Pollution / Biochemical composition / Carbon / Carbon - analysis / Carbon - chemistry / chemical composition / chemistry / Contaminated sediments / Earth and Environmental Science / Ecotoxicology / Environment / Environmental Chemistry / Environmental Health / Environmental Monitoring / Fulvic acids / Geologic Sediments / Geologic Sediments - chemistry / Ghana / Humic acids / Humic Substances / Hydrogen-Ion Concentration / Lake sediments / Lakes / Lakes - chemistry / Mercury / Mercury - analysis / Mercury - chemistry / Methylmercury / methylmercury compounds / Organic carbon / Pollution / sampling / Sediment samplers / sediments / Soil Science & Conservation / Sulfates / Sulfates - chemistry / Sulfur content / Waste Water Technology / Water Management / Water Pollutants, Chemical / Water Pollutants, Chemical - analysis / Water Pollutants, Chemical - chemistry / Water Pollution Control