Publication Date:
2023-03-07
Description:
Chemical contaminants are released from mining, domestic and industrial effluents into an aquatic environment. Sediments (n =
10) were collected with an Eckman grab at ten stations in the Densu Estuary for ecological risk assessment. The spatial
distribution of organic characteristics and ecological risk of metals—zinc, lead, copper, mercury, iron, and manganese in
sediment—were analyzed using standard methods. The organic parameters occurred in the ranges, as follows: % C, 0.76 to
2.05, % TN, 0.06 to 0.015; % TP, 0.44 to 1.38; and C/N, 12.31 to 34.81. The ranges of metal concentrations (mg/kg) were as
follows: Fe, 201.10 to 720.90; Mn, 40.10 to 152.70; Zn, 7.3 to 158.3; Pb, 1.9 to 84.7; Cu 3.4 to 23.0; and Hg, 0.01 to 0.05. The
mean concentration of metals in the sediment were Fe 〉 Mn 〉 Pb 〉 Zn 〉 Cu 〉 Hg. The highest mean concentration of Fe
suggested redox conditions in the Densu Estuary. There is a low contamination factor (CF) for five metals (Zn, Hg, Fe, Cu, and
Mn) (CF 〈 1) to high contamination of Pb (3 〈 CF ≤ 6). The average Pb concentration was above local and geological backgrounds,
suggesting an anthropogenic source of pollution from industrial and domestic effluents and agrochemicals. The
sediment was extremely enriched by Pb (EF 〉 50) with a positive index of geoaccumulation (0 〈 Igeo ≤ 2) than other metals.
There is considerable to a very high degree of contamination (DC) (3 ≤ DC ≥ 6) of metals in the sediment of Densu Estuary. The
potential ecological risk index (≤ 40 PERI 〈 80) suggested a very low to moderate ecological risk of metal pollution. The study
provides baseline knowledge on geochemical contamination in tropical estuarine systems for the development of effective
chemical control strategies towards sustainable management of coastal waters.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
Format:
application/pdf
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