|
Abstract:
|
In many countries slow sand filtration (SSF) plants have faced a number of operational problems, the most serious of which are caused by high turbidity and suspended solids concentration in the raw water. Therefore it is necessary to pretreat the raw water to reduce turbidity to the required level of SSF. The main objective of this study was to investigate the appropriateness of horizontal flow roughing filters as pretreatment for SSF in water purification in Tanzania with particular emphasis to rural supply schemes. Community participation, construction and operational features of existing HRF plants, their removal efficiency with respect to turbidity, fecal coliform and color were investigated together with other indicative parameters. Filter efficiency regenerations through hydraulic filter cleaning was also investigated. This study was based on rewiew of existing literature, physical inspection of existing plants, information and experiences from the plants in Rukwa, Mbeya and Iringa regions and on the field tests conducted at the Iringa urban pilot HRF plant. /Kir11 |