Flotation of Peat Particles by Dissolved Organic Matter Eluted from the Re-Deposited Tropical Peat in Tropical Peatland Coast

Abstract

On Bengkalis Island, Indonesia, coastal erosion discharges peat into the sea, which then returns to form a peat beach. Groundwater flows from peat cliffs to the sea, generating foam along the shoreline. Peat particles float on the sea surface and are attached to this foam. This study examined water quality, microorganisms, and the foaming properties of groundwater and seawater around the peat beach. High foaming properties of groundwater were observed, along with high dissolved organic carbon and nitrogen concentrations. Microorganisms in the groundwater in the peat beach were diverse, with an increase in actinobacteria, which decompose peat. Experimental data indicated that groundwater’s high foaming properties help float peat particles, affecting their transport. Peat flotation experiments showed increased flotation with higher groundwater concentration. The specific environment of the peat beach, such as neutral pH, may promote peat decomposition, with surfactants generating in the process affecting peat particle behavior. This study suggests that peat decomposition is enhanced on peat beaches where previously discharged peat particles have been deposited along the shoreline.