Patent ID: 6953525
Filing Date: 2005-10-11
Classification: C02F

Abstract:
1. A package plant for treating raw water to produce potable water, said package plant comprising: an inlet for receiving water to be treated; an ozonator for disinfecting said water; a contact column to permit ozone from said ozonator to mix with said water, said contact column having a vent to remove free ozone from said water before said water is directed to an upflow roughing filter, said up-flow roughing filter including at least one lower coarse filter media for removing coarse solids from said water, and at least one upper less coarse chemically active filter media for removing less coarse solids from said water and any disinfection residuals and byproducts from said ozonator, said water flowing through said lower filter first and then through said upper filter; and a down-flow slow sand filter, said slow sand filter being sized and shaped to promote a biomass growth for further purifying said water, wherein said chemically active filter media protects said biomass from residual disinfectants and contributes to the removal of the byproducts of disinfection.