Geochemical assesment of heavy metals in postmining laterite nickel, North Konawe Southeast Sulawesi

Abstract

This study aims to determine the concentration and migration of various heavy metals in soil texture. A total of 21 soil samples from Block A (12 samples) and Block B (9 samples), were inductively combined with ICP-OES methodology to determine the concentration levels of Mn,Cr,Ni,Fe,Zn and ICP-MS for Co,Pb,Cd in soil samples as toxic contaminants. The results showed I-geo indicated contamination levels that ranged from practically uncontaminated for Cd, uncontaminated to moderately for Pb, uncontaminated to moderately contaminated soil for Fe, moderately contaminated for Co,Zn,moderately to heavily contaminated For Mn,Ni , heavily contaminated for Cr. I-geo relationship and heavy metal concentration. Although Block A and Block Igeo have the same category, which is of concern are Cd and Pb, the concentrations of these two heavy metals are very small. Generally, Cd and Pb react chemically under acidic conditions, whereas lateritic soil is an alkaline oxide soil. Heavy metals Cr and Mn function freely to control the mobility of Fe, Co, Ni. And Fe only controls Co and Ni. While Pb, Zn Cd are included in the low mobility group or zero contamination. Multidimensional scaling statistics (MDS) for two-dimensional mapping in blocks A Mn, Co, Ni, Cr shows active mobility following the soil depth where the chemical function of Fe controls the mobility of Mn so that the concentration of Mn increases, three-dimensional mapping shows that Cr and Fe function to control the mobility of Co, Mn,Ni so that the concentration increases. Two-dimensional mapping in Block B, Cr and Mn functions freely to control the mobility of Fe, Co, Ni. And Fe only controls Co and Ni. While Pb, Zn Cd are included in the low mobility group or zero contamination, three-dimensional mapping is known to have active concentrations of Cr and Mn and control the mobility of Ni, Co, Fe.