A study of copper sorption in soils as influenced by soil characteristics using a laboratory column leaching technique

Decisions on containment of potential Cu toxicity require an understanding of its behaviour in the soil. Two experiments arranged in a Randomized Complete Block Design (RCBD), with four replications, were carried out separately, to assess the distribution of Cu. The treatments were 0.00, 12.33, 18.50 and 24.70 g/m2. Two different soils, Gleyic Arenosol (Nta series) and Eutric/Dysteric Gleysol(Temang series) were used for the studies. The study showed Cu sorption increased with increasing soil organic matter (SOM) content. Whilst the correlation between Cation Exchange Capacity (CEC) and Cu sorption was positive in the Gleyic Arenosol, it was negative in the Eutric/Dysteric Gleysol. The clay content did not show any regular pattern with Cu sorption. Copper sorption increased with increasing pH in both soil types. Gleyic Arenosol adsorbed more Cu than the Eutric/Dysteric Gleysol at all levels of Cu application. The results showed the annual Cu movement in the soil to be 4.17 and 4.58 cm y-1 for the Gleyic Arenosol and Eutric/Dysteric Gleysol respectively. Continuous application of Cu may have serious groundwater implications especially under low pH and SOM. Industries processing heavy metals are encouraged to set up large column leaching apparatus to clean industrial effluents before disposing them