Method for treating feed water using a biostratum and filtration media

Abstract

A method of treating water comprising the step of passing water through a vessel comprising a bed of crosslinked resin beads having a height from 10 cm to 2 m, said bed comprising a biostratum at the top of the bed to produce treated water, wherein (a) the area-normalized free void volume in the biostratum is 0.018 m3/m2 or less; (b) the packing density in the biostratum is 0.64 to 0.98; (c) the ratio of the exterior surface area of the resin beads to the total free void volume in the biostratum is less than 2.0 to 50 m2/L; (d) the velocity of the water through the biostratum is 1 to 1,500 biostratum volumes per hour; (e) the Reynolds number of the flow through the biostratum is 0.10 to 3.0; and (f) the vessel comprises an intermediate distributor from 5 to 195 cm below the top of the bed.

Dependencies are inferred from the claim text.