Zeolite composite materials for waste odor control

Abstract

A composite material for environmental odor control is useful in controlling odors from waste, for example, as an alternative daily cover for landfills and in composting applications. The composite material includes a fiber web and a zeolite containing metals to promote absorption of odorous gas.

1 . A waste odor control composite comprising:
 (a) a fiber web; and   (b) one or more zeolites containing between about 0.2% and about 4% Zn by weight, and between about 0.4% and about 4% by weight of one or more metals chosen from K, Li, Mg, Ba and Fe,   wherein the odor control composite has a weight per unit area between about 30 g/m 2  and about 250 g/m 2  and a tensile strength between about 10 Nm/g and about 200 Nm/g.   
     
     
         2 . The odor control composite of  claim 1 , wherein the odor control composite has a weight per unit area between about 40 g/m 2  and about 150 g/m 2 . 
     
     
         3 . The odor control composite of  claim 1 , wherein at least one zeolite is incorporated within the fiber web. 
     
     
         4 . The odor control composite of  claim 1 , wherein at least one zeolite is incorporated within the fiber web and has a median particle size of less than about 50 microns with 95% of the particles smaller than about 100 microns. 
     
     
         5 . The odor control composite of  claim 1 , wherein at least one zeolite is coated on a surface of the fiber web. 
     
     
         6 . The odor control composite of  claim 1 , wherein at least one zeolite is coated on a surface of the fiber web and has a median particle size of less than about 25 microns with 95% of the particles smaller than about 50 microns. 
     
     
         7 . The odor control composite of  claim 1 , wherein at least one zeolite contains between about 1% and about 3% Zn by weight. 
     
     
         8 . The odor control composite of  claim 1 , wherein at least one zeolite contains between about 0.4% and about 4% by weight of one or more metals chosen from K, Li, Mg and Ba. 
     
     
         9 . An odor control composite comprising:
 (a) a fiber web; and   (b) one or more first zeolites incorporated within the fiber web, wherein the one or more first zeolites contains between about 0.2% and about 4% Zn by weight, and between about 0.4% and about 4% by weight of one or more metals chosen from K, Li, Mg, Ba and Fe, and wherein the one or more first zeolites has a median particle size of less than about 50 microns with 95% of the particles smaller than about 100 microns; and   (c) one or more second zeolites coated on a surface of the fiber web, wherein the one or more second zeolites contains between about 0.2% and about 4% zinc by weight, and between about 0.4% and about 4% by weight of one or more metal ions chosen from K, Li, Mg, Ba and Fe, and wherein the one or more second zeolites has a median particle size of less than about 25 microns with 95% of the particles smaller than about 50 microns.   
     
     
         10 . The odor control composite of  claim 9 , wherein at least one zeolite contains between about 1% and about 3% Zn by weight. 
     
     
         11 . The odor control composite of  claim 9 , wherein at least one zeolite contains between about 0.4% and about 4% by weight of one or more metals chosen from K, Li, Mg and Ba. 
     
     
         12 . The odor control composite of  claim 9 , wherein the composite has a weight per unit area between about 30 g/m 2  and about 250 g/m 2 . 
     
     
         13 . The odor control composite of  claim 9 , wherein the composite has a tensile strength between about 10 Nm/g and about 200 Nm/g. 
     
     
         14 . A method of making an odor control composite, the method comprising:
 (a) contacting at least one zeolite with a solution of one or more metal ions, whereby the one or more metal ions diffuses into the zeolite to form at least one ion exchanged zeolite;   (b) preparing first zeolite particles of at least one ion exchanged zeolite having a median particle size of less than about 50 microns with 95% of the particles smaller than about 100 microns;   (c) contacting fibers with a liquid to form a slurry;   (d) incorporating the first zeolite particles into the fiber slurry;   (e) forming a fiber web from the slurry;   (f) preparing second zeolite particles of at least one ion exchanged zeolite having a median particle size of less than about 25 microns with about 95% of the particles smaller than about 50 microns; and   (g) applying the second zeolite particles to one or more surfaces of the fiber web.   
     
     
         15 . The method of  claim 14 , wherein contacting the zeolite with a solution of one or more metal ions comprises contacting the zeolite with a solution containing Zn +2 . 
     
     
         16 . The method of  claim 14 , wherein contacting the zeolite with a solution of one or more metal ions comprises contacting the zeolite with a solution containing one or more metal ions chosen from K + , Li + , Mg 2+ , Ba 2+ , Fe 2+  and Fe 3+ . 
     
     
         17 . The method of  claim 14 , wherein contacting the zeolite with a solution of one or more metal ions comprises contacting clinoptilolite with a solution containing Zn +2 . 
     
     
         18 . The method of  claim 14 , wherein contacting fibers with a liquid to form a slurry comprises combining wood pulp with water. 
     
     
         19 . The method of  claim 14 , wherein forming a fiber web from the slurry comprises a wet-laid process. 
     
     
         20 . The method of  claim 14 , wherein forming a fiber web from the slurry comprises a fourdrinier or twin wire forming process.