Particle Removal and Head Loss Development in Biological Filters

The physical performance of granular media filters was studied under prechlorinated, back-chlorinated, nonchlorinated conditions. Overall, biological filtration produced a high-quality water. Although effluent turbidites showed little difference between the performance of biological filters and conventional prechlorinated filters, differences were shown with particle counts. Although prechlorination yielded slightly better net particle removal than biological filtration, the overall order of magnitude and size range of particles removed was similar. Biological filtration also produced economical filter run times.