Water purification pack

Abstract

An apparatus and methods are disclosed for purifying fluid, such as potable water, to quality levels suitable for medical application, particularly to applications involving injection of the fluid into a human body. The apparatus comprises a portable purification pack constructed for a single use. The pack houses depth filtration, activated carbon, mixed bed ion exchange resins and terminal filtration stages in series. The terminal filter comprises a fine (microfiltration or ultrafiltration), permeable membrane, treated with an endotoxin-binding chemistry. In contrast with semi-permeable osmotic membranes, the permeable membrane produces high flow rates at relatively low pressures, while still safely purifying fluid to injection quality.

1 . A method of producing injectable quality fluid, comprising: 
 providing a housing surrounding a plurality of purification elements, the housing having a fluid flow path through the purification elements from an inlet to an outlet;    supplying non-sterile fluid to the inlet under a feed pressure of less than about 20 psi;    flowing the fluid through the plurality of purification elements to form purified fluid; and    outputting the purified fluid from the outlet, wherein the purified fluid has an organic content, conductivity, pH level and particulate contamination level suitable for medical injection.    
     
     
         2 . The method of  claim 1 , further comprising injecting the purified fluid into a human body.  
     
     
         3 . The method of  claim 1 , further comprising dissolving reagents in the purified fluid.  
     
     
         4 . The method of  claim 3 , wherein dissolving reagents in the purified fluid comprises passing the purified fluid from the outlet into a reagent cartridge containing dry reagents to form a medical solution.  
     
     
         5 . The method of  claim 4 , wherein the medical solution comprises peritoneal dialysate.  
     
     
         6 . The method of  claim 1 , wherein the purified fluid outputted from the outlet has a flux rate of greater than about 30 mL/min.  
     
     
         7 . The method of  claim 6 , wherein the purified fluid outputted from the outlet has a flux rate of greater than about 90 mL/min.  
     
     
         8 . The method of  claim 7 , wherein the feed pressure is between about 5 psi and 10 psi.  
     
     
         9 . The method of  claim 1 , wherein the plurality of purification elements comprises a filter having a porosity of no more than about 0.5 μm.  
     
     
         10 . The method of  claim 1 , wherein the purified fluid has a total organic content of less than about 500 ppb; conductivity of less than about 2.0μ Siemens; pH between about 4.5 and 7.5; fewer than about 12 particles/mL of particles greater than 10 μm; fewer than about 2 particles/mL of particles greater than 25 μm; and lower than about 0.025 ng/mL of endotoxins.  
     
     
         11 . A method for producing fluid for medical injection, comprising: 
 providing a portable housing containing purification elements;    flowing non-sterile fluid through the purification elements;    retaining particulate contamination, organic matter, dissociated ions, and endotoxins from the fluid within the purification elements to produce purified fluid; and    outputting the purified fluid from the housing after retaining particulate contamination, organic matter, dissociated ions, and endotoxins from the fluid, the purified fluid being suitable for medical injection.    
     
     
         12 . The method of  claim 11 , wherein the purification elements comprise a bed of ion-exchange resins.  
     
     
         13 . The method of  claim 11 , wherein the purification elements comprise a depth filtration stage and an organic filtration stage.  
     
     
         14 . The method of  claim 11 , wherein retaining endotoxins comprises passing the fluid through a permeable membrane treated with a quaternary amine exchange chemistry.  
     
     
         15 . The method of  claim 11 , wherein retaining endotoxins comprises passing the fluid through a permeable ultrafiltration membrane having a nominal cut-off porosity of between about 10,000 and 30,000 molecular weight.  
     
     
         16 . A method of producing injectable quality fluid, comprising: 
 feeding non-sterile fluid into an inlet of a housing comprising a plurality of purification elements, the housing having a length of less than or equal to about six inches and a width of about less than or equal to about five inches;    flowing the fluid through the plurality of purification elements;    retaining within the housing particulate, ionic, and organic contaminants from the fluid as the fluid flows through the plurality of purification elements; and    outputting purified fluid from the housing after flwing the fluid through the plurality of purification elements, wherein the purified fluid is suitable for intravenous use.    
     
     
         17 . The method of  claim 16 , further comprising dissolving dry reagents in the purified fluid.  
     
     
         18 . The method of  claim 16 , wherein the plurality of purification elements comprises a filter having a permeable membrane chemically treated for binding residual endotoxins.  
     
     
         19 . The method of  claim 18 , wherein the permeable membrane has a porosity of about 0.22 μm or less.  
     
     
         20 . The method of  claim 16 , wherein the plurality of purification elements further comprises an organic filtration stage comprising a bed of granular carbon configured to adsorb organic contaminants in the fluid.