Oil and Grease (OG) Content in Seawater and Sediment of the Jakarta Bay and its Surrounding

Abstract

Oil and grease (OG) pollutants were found and measured in seawater and sediment, causing damage to the marine environment. Observations of total concentrations of OG in seawater and sediment have been conducted in the waters of Jakarta Bay and surrounding areas in March 2017. This study investigates the total contamination levels and spatial distribution of OG in seawaters and sediments in the Jakarta Bay and vicinity area. Seawater and sediment samples were taken at six sampling points in three locations; Ancol, Muara Gembong, and Pari Island. The samples were extracted by dichloromethane and n-hexane solvent, followed by an analysis in the Fourier Transform Infra-Red (FTIR) instrument at a wavelength of 2900-3000 cm-1. The concentration of OG in seawater from Ancol, Muara Gembong, and Pari Island has an average of 258.547 mg/L, 114.454 mg/L, and 240.533 mg/L, respectively. On the other hand, the OG levels in sediments from Ancol, Muara Gembong, and Pari Island have a mean concentration of 18.084 mg/kg, 17.218 mg/kg, and 15.254 mg/kg, respectively. The result showed that the level of OG obtained in these waters is higher than the threshold value based on the Decree of Environment Ministry No. 51/2004 regarding seawater quality, meanwhile in the sediment sample is lower than the threshold value based on the Australian and New Zealand Environment and Conservation Council (ANZECC) sediment quality guidelines (SQGs).