Assessment of heavy metals contamination in the sediment of Yardantsi reservoir, Gusau Nigeria

Abstract

The magnitude and ecological relevance of metals pollution in the sediment of Yardantsi Reservoir, Gusau Nigeria, which serve as main source of water for irrigation and municipalities was assessed by applying sets of complementary sediment quality assessment methods; The contamination factor (C_f); and comparisons with concentration based sediment quality guidelines (CBSQGs) of target heavy metals. The sediment metals concentrations in the reservoir were investigated from May, 2015 to April, 2017. Sediment samples were collected from five sampling stations and analysed using Shimadzu AA6800 Atomic Absorbtion Spectrophotometry. The results showed that Cd has a mean concentration of (1.81cmol/kg). Cu (3.40cmol/kg), Cr (0.99cmol/kg), Fe (46.71cmol/kg), Ni (0.50cmol/kg), Pb (0.14cmol/kg), and Zn (13.87cmol/kg). Contamination factor (C_f) and CBSQGs suggested that cadmium concentration was slightly higher as C_f>6 and exceeded threshold effects concentrations (TECs). This may cause adverse biological effects and the reservoir was in potential risk with regards to Cd concentration, while the rest of the metals were found to be lower than the proposed TECs and has C_f<1 indicating that there are no harmful effects from these metals. It is suggested that the reservoir input should be monitored and the sediment sources be mitigated.

Keywords: Assessment, contamination, heavy metals, reservoir, sediment