EFFECTS OF CONTACT SOLIDS ON SESSILE ALGAE EROSION

Hyperplastic periphyton caused by eutrophication is eyesore and emit a stench. Inorder to preserve riverine environment, periphyton, such as sessile algae and bacteria, need to be detached and washed away at intervals. Although transported sediment seems to have considerable effects on erodingperiphyton, little has been studied on it. In this study, experiment was performed in laboratory streams to examine the effects of contact solids on sessile algae erosion. It was found through the experiment that higher solids concentrations, larger particles and faster current quickened erosion. Additionally, a numerical simulation was performed by using the discrete element method in which collisions of particles were considered. The predicted velocity profiles ofparticles and the rate of erosion agreed withthe experimental results.