Sand Filtration of Algal Suspensions

This article discusses a study done by the University of Michigan Sanitary Engineering Laboratories on the ability of sand beds to remove algae from suspension. A controlled laboratory test capable of fixing and maintaining the type and density of algae applied to the bed should lead to an extension of knowledge in this area. The initial experiments were directed towards an evaluation of the filtration of plain algal suspensions through sand beds. Subsequent tests have been conducted using a filter influent composed of both algal and flocculent particles. Such independent variables as sand size, flow rate, bed depth, and type and density of algae have been controlled. Their corresponding effects on bed penetration, head loss, and efficiency of removal have been observed.