Analysis of cobalt (Co) in the soil of Antang Landfill, Makassar City, South Sulawesi Province, Indonesia by use of ICP-OES

Abstract

This study analyzed the content of cobalt (Co) heavy metal in the soil conducted around the Final Disposal Sites landfill of Antang Makassar, Indonesia. There were 12 sampling points such as points A1, A2, and A3 (line A); points B1, B2, and B3 (line B); points C1, C2, and C3 (line C); and points D1, D2, and D3 (line D). Every sampling points have a depth of 30 cm vertically, and the soil samples were divided into three layer (upper layer, middle layer, and lower layer) with a depth of 0-10 cm (upper layer), 10-20 cm (middle layer), and 20-30 cm (lower layer). The study used 36 samples all of which were analyzed using ICP-OES to measure the concentrations of heavy metals. The concentration of heavy metals in the soil around landfill of Antang had spread vertically and laterally. The analysis found that cobalt (Co) heavy metal concentrations in Line A, Line B, Line C and Line D for every depth exceeded the normal limit. However, on line B the B1 sampling point at a depth of 10-20 cm and 20-30 cm had a relatively normal concentration, which was 10 ppm. That value was the standard permitted by the General of Drug and Food Control as the level of pollution in the soil. Soil pH varies from 4.82 to 6 and is considered acidic. Soil pH significantly affects the solubility and mobility of metals, because most metals dissolve in acidic soils. Thus, remediation or appropriate precautions were needed to prevent risks to humans and the environment.