Freshwater Green Microalga for Bioremediation of River Melaka Heavy-Metals Contamination

Abstract

Heavy metals toxicity can adversely affect aquatic life and in some cases result in massive fish mortalities. Recent observation of fish mortalities floating on the surface of Bandar Hilir (city center) section of  Melaka River (Latitude 2.194871, Longitude 102.248950) but none in the section of the river close to the open sea (latitude 2.193556, Longitude 102.247048) necessitated research into the cause. This work looks into heavy metal contamination as a possible cause. It also presents the use of wastewater culture method for growing an indigenous microalga Scenedesmus sp. while simultaneously serving as a means for bioremediation of the river water. Water sample from the two sections were collected for laboratory analysis. This research used Inductively coupled plasma mass spectrometry (ICP-MS) to detect the presence and concentration of selected heavy metals in the two different sections. The results show a significantly higher concentration of Zn in the section with fish mortalities than the section were no mortality was seen. The bioremoval experiment shows that the living cells of microalgae Scenedesmus sp. took up 97%  and 99% of the Zn after three and seven days respectively. These results indicate (1) possibility of Zn contamination and (2) excellent bioremediation potential of this contamination with Scenedesmus sp.