Effect of Cassava Processing Mill Effluent on Physical and Chemical Properties of Soils in Abraka and Environs, Delta State, Nigeria

Abstract

Selected heavy metals and physicochemical characteristics of the soils around some cassava processing mills in Abraka and environs were analyzed in order to assess the impact of the cassava mill effluent on the soils. The results of the physicochemical analysis showed overall decrease in pH values and corresponding increase in the other parameters. The pH values indicated that the soils were acidic which suggests that the effluents imparted acidic property on the soils. The elevated levels of Total Organic Carbon and Total Nitrogen are suggestive of increased organic matter and microbial activities in the effluent residues. Electrical conductivity values indicate presence of dissolved inorganic salts while the phosphorus values confirm the rich source of phosphorus in cassava tuber. The result of heavy metal analysis shows elevated levels of heavy metals in the soil receiving cassava mill effluent. The relative potential index and enrichment coefficient values of the metals in the soils coupled with the observed physiochemical characteristics revealed that there are some levels of heavy metal enrichment, contamination and bioavailability in the soils studied.

Key words: cassava mill effluent, heavy metals, physicochemical characteristics soil pollution, Abraka