Modelling of environmental phytoremediation in eutrophic river — the case of water hyacinth harvest in Tha-chin River, Thailand

This study indicates the potential utility of water hyacinth for nutrient removal and biomass production, based on the continuous harvest at the maximum sustainable yield (MSY). Two types of surplus production–harvest models of water hyacinth are constructed to manage the water quality of rivers in both rainy and dry seasons. The models are expected to be a simple but adequate tool of pollution control for diffuse sources in the long term. The case study with Tha-chin River in Thailand shows that effective nutrient removal can be achieved under biomass control by harvesting at MSY. Nutrient removal in the rainy season is also investigated taking into account the quantity of biomass that flows in and out of the river basin.