Water treatment process

Abstract

The present invention relates to water treatment, in particular to a process for the removal of dissolved organic carbon from water. The process includes the following steps, adding an ion-exchange resin to water containing a contaminant such as dissolved organic carbon, dispersing the resin in the contaminated water to enable adsorption of the dissolved organic carbon onto the resin, and separating the resin loaded with contaminant from the water. In a preferred embodiment the process employs a magnetic ion-exchange resin.

We claim:  
     
         1 . A process for the removal of dissolved organic carbon from water, which process includes the following steps: 
 a) dispersing a magnetic ion-exchange resin in water containing dissolved organic carbon to enable adsorption of the organic carbon from the water onto the resin: and    b) separating the magnetic ion-exchange resin loaded with organic carbon from the water.    
     
     
         2 . A process according to  claim 1  wherein the magnetic ion exchange resin is dispersed by adding the magnetic ion-exchange resin to the water while imparting sufficient shear on the water to disperse the resin in the water.  
     
     
         3 . A process according to  claim 1  wherein the magnetic ion exchange resin loaded with organic carbon is separated from the water by 
 i) agglomerating the magnetic ion-exchange resin loaded with the organic carbon; and  
 ii) separating the agglomerated magnetic ion-exchange resin loaded with organic carbon from the water.  
 
     
     
         4 . A progress according to  claim 3  wherein the resin is dispersed by mechanical agitation, mixing pumps immersed in the water or air agitation.  
     
     
         5 . A process according to  claim 3  wherein the loaded resin is separated from the water by settling, screening or a combination thereof.  
     
     
         6 . A process according to  claim 3  wherein the loaded resin is separated from the water by settling and wherein the ion exchange resin is more dense than the water.  
     
     
         7 . A process according to  claim 6  wherein the settled resin is collected by vacuum collection.  
     
     
         8 . A process according to  claim 6  wherein the settled resin is collected by magnetic transport.  
     
     
         9 . A process according to  claim 6  wherein the settling is facilitated by tilted plates or tubular modules.  
     
     
         10 . A process according to  claim 1  which is a process for the removal of contaminants from solution wherein the ion-exchange resin is dispersed in the contaminated water.  
     
     
         11 . A process according to  claim 1  wherein said process further comprises a step of disinfecting the water.  
     
     
         12 . A process for the production of potable water suitable for distribution and consumption from a raw water source which comprises the steps of  claim 1 .  
     
     
         13 . A process for the treatment of waste water which comprises the steps of  claim 1 .  
     
     
         14 . A process according to  claim 1  for the removal of dissolved organic carbon from water, which process includes the following steps: 
 a) adding a magnetic ion-exchange resin to water containing dissolved organic carbon, while imparting sufficient shear on the water to disperse the resin in the water, thereby enabling adsorption of the dissolved organic carbon onto the magnetic ion-exchange resin;  
 b) agglomerating the magnetic ion-exchange resin loaded with the organic carbon;  
 c) separating the agglomerated magnetic ion-exchange resin loaded with organic carbon from the water;  
 d) regenerating a portion of said agglomerated resin, with the remainder being returned to step a), thereby allowing continuous treatment of the water; and  
 e) returning regenerated agglomerated resin to step a).  
 
     
     
         15 . A progress according to  claim 14  wherein the resin is dispersed by mechanical agitation, mixing pumps immersed in the water or air agitation.  
     
     
         16 . A process according to  claim 14  wherein the loaded resin is separated from the water by settling, screening or a combination thereof.  
     
     
         17 . A process according to  claim 16  wherein the loaded resin is separated from the water by settling and wherein the ion exchange resin is more dense than the water.  
     
     
         18 . A process according to  claim 17  wherein the settled resin is collected by vacuum collection.  
     
     
         19 . A process according to  claim 17  wherein the settled resin is collected by magnetic transport.  
     
     
         20 . A process according to  claim 17  wherein the settled resin is collected by filtration.  
     
     
         21 . A process according to  claim 17  wherein the settling is facilitated by tilted plates or tubular modules.  
     
     
         22 . A process according to  claim 17  wherein gravity settling is employed.  
     
     
         23 . A process according to  claim 14  wherein the ion-exchange resin has cationic functional groups.  
     
     
         24 . A process according to  claim 14  wherein the ion-exchange resin is particulate and the particles have a diameter less than 100 μm.  
     
     
         25 . A process according to  claim 24  wherein the ion-exchange resin particles have a diameter in the range of from 25 μm to 75 μm.  
     
     
         26 . A process according to  claim 14  wherein the ion-exchange resin is macroporous.  
     
     
         27 . A process according to  claim 14  wherein the ion-exchange resin is manufactured from cross-linked polystyrene based polymers.  
     
     
         28 . A process according to  claim 14  wherein the ion-exchange resin is present in the water in the range of from 0.5 to 5 ml of wet resin per litre of water.  
     
     
         29 . A process according to  claim 11  wherein the resin regeneration process includes the following steps: 
 i) packing the spent resin into a column; and  
 ii) passing brine through the packed column for desorption of the dissolved organic carbon from the resin.  
 
     
     
         30 . A process according to  claim 14  which comprises a process for the removal of contaminants from solution wherein the ion-exchange resin is dispersed in the contaminated water.  
     
     
         31 . A process according to  claim 14  wherein said process further comprises a step of disinfecting the water.  
     
     
         32 . A process according to  claim 31  wherein the water is disinfected after treatment with ion exchange resin.  
     
     
         33 . A process according to  claim 32  wherein the water is disinfected with chlorine.  
     
     
         34 . A process according to  claim 14  wherein said process is a pre-treatment prior to subjecting the pretreated water to membrane filtration.  
     
     
         35 . A process according to  claim 14  wherein said process is a pretreatment prior to subjecting the pretreated water to a coagulation/sedimentation process.  
     
     
         36 . A process according to  claim 14  wherein the process further comprises a step of treating the water with activated carbon after treatment with ion-exchange resin.  
     
     
         37 . A process according to  claim 11  wherein the resin regeneration process includes the following steps: 
 i) adding the magnetic ion-exchange resin loaded with organic carbon to brine;  
 ii) dispersing the loaded magnetic ion-exchange resin in the brine for the desorption of the organic carbon from the magnetic ion-exchange resin to regenerate the resin;  
 iii) agglomerating the regenerated magnetic ion-exchange resin; and  
 iv) separating the regenerated magnetic ion-exchange resin from the brine.  
 
     
     
         38 . A process for the production of potable water suitable for distribution and consumption from a raw water source which comprises the steps of  claim 1 .  
     
     
         39 . A process for the treatment of waste water which comprises the steps of  claim 1 .  
     
     
         40 . A water treatment process which comprises the steps of: 
 a) removing dissolved carbon from the water by the process of  claim 14;     b) subjecting the water from which dissolved carbon has been removed to a coagulation or sedimentation process.    
     
     
         41 . A water treatment process which comprises the steps of: 
 a) removing dissolved carbon from the water by the process of  claim 14;     b) subjecting the water from which dissolved carbon has been removed to a membrane filtration process.