Assessment of physicochemical properties and heavy metals pollution in Andoni Estuary of Rivers State, Nigeria

Abstract

The study was on the assessment of physicochemical properties and heavy metals concentration in the sediments of Andoni Estuary. Samples were collected at five stations: Station 1 (Agan-asuk), station 2 (Atasuk-ile), station 3 (Otutibi), station 4 (Ama-Amaramu) and station 5 (Ibot-inyon), once quarterly for a period of one year between April 2021 to March 2022. The various physicochemical variables were analyzed in the laboratory following the normal APHA procedures. The following heavy metals Cadmium, (Cd), Lead (Pb) Copper (Cu), Mercury (Ag) and Nickel (NI) were analyzed using an atomic absorption spectrophotometer, to determine their concentration in the water. The result obtained in this study showed that the Physicochemical properties investigated showed a very high level of variation among the parameters. pH value ranged between 1.2 to 7.31 which is within the WHO limit of 6.5 to 9.5. The contamination factor of the individual heavy metals in Sediment samples were as follows; Cd varied <0.01 – 0.02, Pb varied from 1.3-9.4, Cr was between 23 - 40, Ni was between 21.1 – 24.1, Zn varied between 57 - 158, and Cu varied from 13.2 – 21.9. When compared to the contamination and pollution intervals as well as the interpretations in the WHO permitted limit, these results are greater. It was determined that the current level of concentrations of heavy metals that were measured in the Andoni Estuary were typically greater than the set allowable limit as suggested by WHO. This was the conclusion that was reached.