| 摘要 |
A water treatment process for removing turbidity-causing impurities from water which involves contacting water containing such impurities with a relatively small amount of filter aid material, e.g., diatomaceous earth, for a time sufficient for impurities in the water to become adsorbed on said filter aid material, passing the water containing the filter aid material with impurities adsorbed thereon through a pre-filter having a flow rate of two liters/min./sq. m., or greater, and thereafter through a filter medium in the form of a porous, non-woven matrix consisting essentially of randomly arranged, irregularly intersecting and overlapping cellulose fibers intermixed with micro-bits of an expanded thermoplastic styrene-polymer or lower polyolefin, or of a flexible foamed polyurethane. The filter medium also includes one or more additional materials from the group of a fibrous wet web strengthening agent, a wet web support releasing agent a wet-strength enhancing agent and an adsorption agent selected from finely divided activated carbon, diatomaceous earth, colloidal alumina monohydrate and ion exchange resin. A system for carrying out the water treatment process is also disclosed.
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