Abstract
This research was carried out to appreciate a slow sand filtration treatment by an investigation of suspended matter distribution in sand beds of Ishifune and Someya slow sand filters. The core-sampler was inserted to take suspended matter in slow sand filter beds during the filter operation when the filters were easy to clog in winter. The following results were obtained.
From the depth distribution of the Total Organic Carbon, Someya slow sand filter detained larger amount of suspended matter than Ishifune slow sand filter. And suspended matter was detained until deeper layer of the sand column at Someya water works.
The depth distribution of the Chl/SAND indicated the nearly same profile as TOC distribution.Pheophytin content in the sand column at Someya water works was several times larger at the deeper layer in the sand columns than Ishifune slow sand filter. From the depth distribution of the Chl/TOC ratio, Someya slow sand filter suggested that algae which had brought by inflow water at early times of filter run detained at the upper sand layer. Total cells number of the algae in the sand columns at Someya slow sand filter were from sevral to ten times higher than Ishifune slow sand filter.
