Abstract

Disclosed are filter mats composed of a wet laid, porous, non-woven matrix having randomly arranged, irregularly intersecting and overlapping cellulose fibers intermixed as a cobeat (i.e. beaten together) with micro-bits of an expanded, thermoplastic styrene-polymer or lower polyolefin or of a flexible foamed polyurethane, and which mix also can include any one or more additional such micro-bits and of fiber-forming polyethylene terephthalate polyester fibers, finely divided activated carbon, diatomaceous earth, and colloidal alumina monohydrate. These mats are effective, for example, to remove insoluble particles and/or soluble substances present in liquid, presently primarily aqueous, media particularly in minute amounts, such as undesirable substances in industrial plant waste waters.