Distribution of heavy metals in water and sediment at the Bojonegara nearshore of Banten Bay, Indonesia

Abstract

Heavy metals released to a nearshore environment may vary due to contaminant sources and the seasonally coastal processes. This study revealed how the seasonal variability and potential sources controlled the distribution pattern of several heavy metals and the level of water quality in Bojonegara nearshore of Banten Bay. The water and sediment samples were collected once in January, February, August, September, and October 2020 at six stations representing the river and sea. Heavy metal was determined using the APHA procedure. Cu was detected in August-October, ranging from <0.002 – 0.008 mg/L. The concentrations of Cu, Cd, and Pb in the sediment were detected, varying from <0.02 to 3.90 mg/kg, <0.02-1.68 mg/kg, and <0.02-6.71 mg/kg, respectively. The concentrations of the concerned metals in sediment vary, and their distribution pattern change seasonally. These metals in water and sediments were still safe for the environment and marine biota. This study suggests how contaminant sources and coastal processes could control the contaminant level. In addition, potential sources of heavy metal merely derived from onshore of the Bojonegara, but it could be derived from advection from other areas through the coastal processes.