slow sand filters are as a proper technology for pre-treatment of raw water, with a fine and medium trubidity in small communities in developing countries. thus, with a minimum operation cost and minimum need for expest bodies have the maximum efficiency. the purpose of this research is carried out to evaluate the efficiency of two processes of horizontal flow roughing filter and vertical flow ...

abstract background: the aim of this study was to compare the efficiency of conventional slow sand filter with modified filter bed with crushed recycled glass in removing of turbidity and total and fecal coliforms from water resources.   methods: in this study efficiency of conventional slow sand filter and modified filter bed with crushed recycled glass during 4 months was compared and their p...

SECONDARY TREATMENT OF SULLAGE WASTEWATER USING ROUGH AND SLOW SAND FILTRATION A. El-Morsy Ahmed Water Engineering Dept., Faculty of Engineering, Tanta University, Tanta, Egypt Abstract: Challenges of wastewater treatment concerning high construction cost of the wastewater treatment plants and operation and maintenance, also the requirements of highly qualified operators, specially with the mec...

Engineering enhancement of slow sand filtration has been an enigma in large part because the mechanisms responsible for particle removal have not been well characterized. The presumed role of biological processes in the filter ripening process nearly precluded the possibility of enhancing filter performance since interventions to enhance biological activity would have required decreasing the qu...

The removal of contaminants in slow sand filters occurs mainly in the colmation layer or schmutzdecke a biologically active layer consisting of algae, bacteria, diatoms and zooplankton. A ripening period of 6 8 weeks is required for this layer to form, during which time filter performance is sub-optimal. In the current study, an environmental scanning electron microscope was used to visualise t...

This study describes the new design and function of a modified version of a traditional slow sand filter. The Submerged Pond Sand Filter is built inside a pond and has a vertical as well as a horizontal flow of water through a sloped filter opening. The filter provides treated drinking water to a rural Indian village. The filter has functioned with minimal maintenance for five years without bei...