Flocculants are used in both the treatment of municipal sewage and industrial wastewater. There are many different types of flocculant chemicals and wastewater treatment systems. Flocculants cause the suspended solids in wastewater to float to the top or sink to the bottom, where they can be removed. They also can be used in storm water treatment systems and in drinking water filtration. In industrial applications, they efficiently remove oil, heavy metals, ink and other contaminants from water.