Settling of peat in sedimentation ponds

Abstract

Settling ponds are used to prevent erosion and the transport of suspended material from peat mines into downstream watercourses. In this study, three different sedimentation ponds were compared under laboratory conditions. The ponds were built on 1/10 and 1/20 scales. Two types of experiments were carried out. Hydraulic characteristics were determined using tracers and the flow‐through curve approach. The efficiency of removal was measured by the settling of peat during constant inflows. The results of settling experiments show that a circular vortex‐settling basin is superior in the reduction of suspended solids during high hydraulic loads; a rectangular basin favours settling during low flow. Because, during constant surface load, the settling efficiency decreases with increasing depth, due to increased turbulence, it is suggested that sufficient settling is achieved by shallow artificial floodplains.