Adsorption vessels

Abstract

The present invention relates to a filtration unit containing pellets or granules of fine-particle iron oxides and/or iron oxyhydroxides with a large specific surface area, processes for their production and processes for their use in the filtration units.

What is claimed is:  
     
         1 . A unit suitable for the through-flow of a fluid medium for the removal of a contaminant from the fluid medium comprising 
 a cartridge housing, which comprises a vessel having a centrally positioned inlet pipe, flat filter layers, a cover ensuring the inflow and outflow of the medium, together with a base part, wherein the cartridge housing is filled with at least partially some particles prepared from fine-particle iron oxide and/or iron oxyhydroxide having a BET surface area of 50 to 500 m 2 /g.    
     
     
         2 . The unit of  claim 1 , wherein the cartridge housing is separated from the cover and/or from the base part by means of a plug-in or screw fitting.  
     
     
         3 . The unit of  claim 1 , wherein the inlet pipe can be removed from the cartridge housing.  
     
     
         4 . The unit of  claim 1  wherein the fluid medium is a gas.  
     
     
         5 . The unit of  claim 4 , wherein the flat filter units comprise a hydrophobic membrane.  
     
     
         6 . The unit of  claim 5 , wherein the membrane displays a pore diameter in the range from 0.2 to 0.5 μm.  
     
     
         7 . The unit of  claim 5 , wherein the hydrophobic membrane comprises polytetrafluoroethylene.  
     
     
         8 . The unit of  claim 1  wherein the fluid medium comprises a liquid.  
     
     
         9 . The unit of  claim 8  wherein the medium comprises an aqueous liquid.  
     
     
         10 . The unit of  claim 9 , wherein the flat filter units comprise a hydrophilic membrane.  
     
     
         11 . The unit of  claim 10 , wherein the hydrophilic membrane is a membrane adsorber.  
     
     
         12 . The unit of  claim 9 , wherein the membrane displays a pore diameter in the range from 0.2 to 0.5 μm.  
     
     
         13 . The unit of  claim 1 , wherein at least one of the flat filter layers is supported on one or both sides.  
     
     
         14 . The unit of  claim 1 , wherein the cover comprises a valve for escaping gases.  
     
     
         15 . The unit of  claim 1 , wherein the housing chamber is in the form of a truncated cone.  
     
     
         16 . The unit of  claim 1 , wherein the cartridge housing can optionally contain iron oxide pigments with BET surface areas below the above limits, whereby the maximum content of these is such that the resistance of the particles to the forces exerted upon it by the flowing medium is sufficiently great that the stress exerted on the particles by the flowing medium does not lead to an undesirable abrasion of the particles.  
     
     
         17 . A process for treating a fluid medium in a unit of  claim 1 , comprising the steps of flowing the medium through the feed nozzle, into the inlet pipe, the strainer basket, any filter material in the base chamber, the lower fritted plate, followed by the adsorbent material in the contact chamber, the upper fritted plate, the cover chamber with filter material and then the outlet pipe via the discharge nozzle.  
     
     
         18 . A process of  claim 17 , wherein the flow of the fluid medium is reversed.  
     
     
         19 . A process comprising the step of treating a fluid medium in a unit according to  claim 1 , by contacting the fluid medium with particles obtained by a process for the production of an adsorbent/catalyst, wherein 
 (a) aluminium, iron, magnesium and/or titanium oxides or (oxy)hydroxides or ageing products and dehydrated secondary products thereof are incorporated into an aqueous suspension of iron oxide and/or iron oxyhydroxide, including Fe(OH) 2  and then    (b) either    (b1) the suspension is dried until it reaches a solid state and the solid material then comminuted mechanically to the desired shape and/or size or    (b2) the suspension undergoes mechanical shaping, optionally in the semisolid state after predrying, followed by additional drying until a solid state is achieved.    
     
     
         20 . The process of  claim 19  wherein the fluid medium comprises water.  
     
     
         21 . The process of  claim 19  comprising removing a heavy metal, phosphorus, antimony, beryllium, selenium, tellurium or cyano compound from water.  
     
     
         22 . The process of  claim 19  comprising removing an arsenic compound from water.  
     
     
         23 . A process comprising the step of treating a fluid medium in a unit according to  claim 1 , by contacting the fluid medium with particles obtained by a process for the production of particles from fine-particle iron oxide and/or iron oxyhydroxide comprising the steps of producing an aqueous suspension of fine-particle iron oxides and/or iron oxyhydroxides having a BET surface area of 50 to 500 m 2 /g, removing the water and dissolved constituents by either 
 I) a) first removing only the water from the suspension, b) introducing the residue thus obtained in water, c) filtering the material obtained, d) washing the residue, and e) either e1) completely dehydrating the filter cake obtained as residue and comminuting the filter cake to the desired shape and/or size or e2) partially dehydrating it to obtain a paste, shaping the paste and subsequently additionally drying the paste until a pellet is obtained, or    II) a) filtering the suspension, b) washing the residue, c) either c1) completely dehydrating the filter cake obtained as residue in the form of a solid to semisolid paste and then comminuting the material thus obtained to the desired shape and/or size or c2) partially dehydrating it to obtain a paste, shaping the paste, followed by subsequent additional drying until a pellet is obtained.    
     
     
         24 . The process of  claim 23  wherein the fluid medium comprises water.  
     
     
         25 . The process of  claim 23  comprising removing a heavy metal, phosphorus, antimony, beryllium, selenium, tellurium or cyano compound from water.  
     
     
         26 . The process of  claim 23  comprising removing an arsenic compound from water.  
     
     
         27 . A container able to be contacted with a fluid medium, at least partially filled with particles agglomerated from fine-particle iron oxide and/or iron oxyhydroxide wherein the particles are prepared from an aqueous suspension of fine-particle iron oxides and/or iron oxyhydroxides having a BET surface area of 50 to 500 m 2 /g, by removing the water and dissolved constituents.