Jc. Goldgrabe et al., PARTICLE REMOVAL AND HEAD LOSS DEVELOPMENT IN BIOLOGICAL FILTERS, Journal - American Water Works Association, 85(12), 1993, pp. 94-106
The physical performance of granular media filters was studied under p
rechlorinated, backwash-chlorinated, and nonchlorinated conditions. Ov
erall, biological filtration produced a high-quality water. Although e
ffluent turbidities showed little difference between the performance o
f biological filters and conventional prechlorinated filters, differen
ces were shown with particle counts. Although prechlorination yielded
slightly better net particle removal than biological filtration, the o
verall order of magnitude and size range of particles removed was simi
lar. Biological filtration also produced economical filter run times.