Analisis Kandungan Cr, Mn, Zn Berdasarkan Kelarutan Dalam Air pada Debu Jalan di Jalan Jenderal Besar A.H. Nasution

Abstract

Road dust can be contaminated with heavy metals from non-exhaust vehicle emission. Rainfall can carry these heavy metals to water bodies and causing pollution that endangers living organism. This research aims to determine the concentration of heavy metals in road dust and the heavy metals that can be carried by stormwater runoff into water bodies. Road dust samples were collected using a vacuum at 3 points on Jenderal Besar A.H. Nasution Road. The samples were sieved using a 200 mesh sieve and then water extraction was carried out to determine heavy metals soluble in water. The residue from the water extraction was wet digested to determine heavy metals that were insoluble in water. The filtrate and residue from water extraction were analyzed using Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) to determine the concentration of heavy metals in road dust. The result of the filtrate showed the concentration of Zn is 0,07 mg/L, while Cr and Mn were not detected, likely due to in insoluble fractions. The result of the residue showed that the concentration of each Cr, Mn, and Zn was 0,38 mg/L; 6,15 mg/L; and 1,81 mg/L, respectively. Zn can exist in soluble fraction such as ZnCl2, while in insoluble fractions, heavy metals can exist as metal oxides such as Cr2O3, MnO2 dan ZnO. Zn has a higher solubilty in water, making it more easily carried by stormwater runoff and pollutes water bodies, compared to Cr and Mn. The solubility of heavy metals was influenced by factors such as temperature, pH of rain, salinity and particle size. This research is expected to provide water body pollution due to heavy metals in road dust from non-exhaust vehicle emission.