Adsorption and filtration mat for liquids

A filter mat for removing particulate, colloidal or dissolved substances from a liquid containing same, said mat being in the form of a non-woven matrix consisting essentially of

• (i) from 10 to 95 weight percent of randomly arranged, irregularly intersecting and overlapping cellulose fibers,
• (ii) from 2 to 90 weight percent of polymer micro-bits produced from an expanded, thermoplastic polymer selected from the group of (a) a styrene-polymer, (b) a lower polyolefin, which is the polymer of an ethylenically unsaturated hydrocarbon monomer having from 2 to 6 carbon atoms, (c) a melt alloy of polyethylene with up to about 10 percent by weight of polystyrene, (d) a copolymer of propylene with from about 20 to about 30 percent by weight of ethylene, (e) a melt alloy composed of at least 50 percent by weight of polypropylene and the balance being a copolymer of ethylene with up to about 30 percent of said copolymer being vinyl acetate, and (f) a flexible foamed polyurethane, each said polymer being non-brittle in expanded form, said polymer micro-bits being substantially completely free of intact cells of the expanded polymer from which they are produced;
• and at least one of the following:
• (iii) from about 1 to 10 weight percent of polyethylene terephthalate fibers;
• or
• (iv) an adsorbing agent selected from the group of:
• (a") finely divided activated carbon in an amount of 70 weight percent or less;
• (b") diatomaceous earth in an amount below that at which undesirable dusting of diatomaceous earth from the mat can occur;
• and
• (c") colloidal alumina monohydrate in an amount sufficient for removing from an aqueous medium a significant portion of any chromic acid, dissolved dichromates and chromic salts contained in said medium, or a combination of two or more of said adsorbing agents.