METAL CONTENTS IN CYPERUS ARTICULATUS AND SEDIMENTS OF ZOBE RESERVOIR, NIGERIA

Abstract

This study evaluated the iron, copper, zinc and lead contents, and the relationship among these metals in Cyperus articulatus and sediments of Zobe reservoir, Dutsinma, Nigeria. Samples of Cyperus articulatus and sediments were obtained, fortnightly for three months, from three sampling locations sited in up-, mid-, and downstream sections of the water body. Standard methods were used in sample collection and preparation while the metal contents were determined spectrophotometrically. In both sample types, copper and zinc were detected at concentrations below 0.5 mg/kg; the sediment samples contained higher iron contents (5.368±1.174 mg/kg) than the plant samples (2.897±2.031 mg/kg) while lead was not detected. The higher metal contents observed in the sediment samples corroborated the importance of aquatic sediment as a sink for metals in aquatic ecosystems. Cyperus articulatus from Zobe reservoir can be deemed safe for use due to its relatively low metal contents (iron 2.897±2.031 mg/kg; copper 0.291±0.119 mg/kg; zinc 0.067±0.111 mg/kg) which were within the allowable limits of local and international standards. The correlative relationship between iron contents in both sample types (R = 0.509) was significant at a 5% confidence level while a significantly stronger association (R = 0.659; 0.681) was observed between iron content in Cyperus articulatus and the copper and zinc concentrations in the sediment samples, respectively. Hence, Zobe reservoir can be referred to as safe from iron, copper, zinc and lead pollution. Periodic assessment of metals in Zobe reservoir is recommended for adequate monitoring of metal levels in the reservoir.