Wastewater treatment

Abstract

An antimicrobial method of treating wastewater and a wastewater antimicrobial dispenser containing an antimicrobial agent for treating a body of wastewater to kill microorganisms by increasing the concentration metal ions therein. The antimicrobial method includes the step of increasing the effectiveness of the biocidal component in the body of wastewater to thereby lessen the need for a supplemental biocide by adding a compound containing a hydantoin ring where the compound containing a hydantoin ring may or may not have any antimicrobial properties. The antimicrobial agent including a source of biocidal metal ions and a compound containing a hydantoin ring where the antimicrobial agent may be a powder, a liquid a solid or combinations thereof.

We claim: 
     
         1 . A method for treatment of greywater containing solid pollutants using a single biocidal component comprising:
 removal of the solid pollutants from the greywater;   adding a concentration of a biocidal component to the body of greywater after removal of the solid pollutants to kill microorganisms in the greywater to render the water suitable for human consumption; and   maintaining the effectiveness of the biocidal component in the greywater by adding a biocidal ineffective compound having a hydantoin ring therein to the greywater to increase the concentration of soluble biocidal component in the greywater to sustain a standard plate count at 35 Degrees Fahrenheit of less than 200 colonies per milliliter.   
     
     
         2 . The method of treatment of greywater of  claim 1  wherein the step of adding a biocidal component to the body of greywater comprises adding a transition metal, a transition metal oxide, a transition metal salt, or a combination thereof to the body of greywater. 
     
     
         3 . The method of treatment of greywater of  claim 2  wherein the step of adding the transition metal, the transition metal oxide, the transition metal salt, or a combination thereof to the body of greywater comprises adding silver, silver oxide, silver salt, or a combination thereof to the body of greywater or a substrate that has been coated or impregnated with metallic silver, silver salt, or a combination thereof. 
     
     
         4 . The method of treatment of greywater of  claim 1  wherein the step of adding the biocidal component to the body of greywater comprises adding a silver-containing material, a silver alloy or a silver nitrate to the body of greywater and the compound containing the hydantoin ring lacks biocidal effectiveness when used alone. 
     
     
         5 . The method of treatment of greywater of  claim 1  wherein the step of adding the compound containing a hydantoin ring comprises adding a compound selected from the group consisting of dimethylhydantoin (DMH) Bromochlorodimethylhydantoin (BCDMH), Dichlorodimethylhydatoin (DCDMH), Dibromodimethylhydantoin (DBDMH). 
     
     
         6 . The method of treatment of waste water of  claim 1  including the step of placing a dispenser containing both the biocidal component and the compound containing a hydantoin ring in the greywater and allowing the greywater to come into contact with both the biocidal component and the compound containing a hydantoin ring. 
     
     
         7 . The method of treatment of waste water of  claim 1  wherein step of adding a compound containing a hydantoin ring includes adding a concentration of 5,5-dimethylhydantoin to the body of greywater to obtain a final concentration of at least 5 ppm 5,5-dimethylhydantoin. 
     
     
         8 . The method of treatment of greywater of  claim 1  wherein the compound containing a hydantoin contains a halogen. 
     
     
         9 . The method of treatment of  claim 1  wherein the step of adding a biocidal component to a body of greywater comprises adding the biocidal component to the greywater after unwanted liquid pollutants are removed from the greywater. 
     
     
         10 . A method of treating a body of wastewater using a single antimicrobial agent to kill microorganisms therein by increasing the effectiveness of an antimicrobial agent comprising the steps of:
 adding a level of a biocidal metal to the body of wastewater to kill microorganisms in the wastewater to render the water suitable for human consumption maintaining a biocidal metal level of between 1.0 ppb to 3.0 ppb in the body of water by adding a source of biocidal metal to the body of wastewater to generate biocidal metal ions in the body of wastewater; and   adding a biocidal ineffective compound containing a hydantoin ring to the body of wastewater;   forming soluble complex of at least the biocidal metal and the biocidal ineffective compound in the wastewater wherein the soluble complex of biocidal metal inhibits the formation of insoluble metal compounds to maintain the effectiveness of the biocidal component in the wastewater to sustain a standard plate count at 35 Degrees Fahrenheit of less than 200 colonies per milliliter.   
     
     
         11 . The method of treatment of  claim 10  wherein the wastewater is greywater or ballast water. 
     
     
         12 . The method of treatment of wastewater of  claim 10  wherein the source of biocidal metal ions comprises a source of silver ions and the compound containing the hydantoin ring comprises 5,5-dimethylhydantoin and the level of 5,5-dimethylhydantoin in the body of wastewater is at least 5 ppm. 
     
     
         13 . The method of treatment of wastewater of  claim 10  wherein the step of adding the source of biocidal metal to the body of wastewater comprises adding a source of metallic silver or metallic silver alloy to the body of wastewater. 
     
     
         14 . The method of treatment of wastewater of  claim 12  including the step of placing a dispenser containing both the source of biocidal metal and the 5,5-dimethylhydantoin in the body of wastewater and allowing wastewater to come into contact with both the source of biocidal metal and the 5,5-dimethylhydantoin. 
     
     
         15 . The method of treatment of wastewater of  claim 11  wherein the step of adding the source of biocidal metal to the body of wastewater comprises adding silver chloride to the body of wastewater. 
     
     
         16 . A wastewater antimicrobial dispenser for killing microorganisms in a body of wastewater comprising;
 a dispenser containing a source of biocidal metal ions releasable into the body of wastewater to generate a santizing level of biocidal metals insufficient to kill the microorganisms in the body of wastewater and a compound containing a hydantoin ring releasable into the body of wastewater wherein the compound containing the hydantoin ring increases the antimicrobial level of biocidal metal ions in the body of wastewater to a biocidal level sufficient to kill microorganism in the wastewater.   
     
     
         17 . The wastewater antimicrobial dispenser of  claim 16  including a first housing having a water accessible compartment containing the biocidal metal; and
 a second housing having a water accessible compartment containing the compound containing a hydantoin ring. 
 
     
     
         18 . The wastewater antimicrobial dispenser of  claim 16  wherein the source of biocidal metal comprises silver chloride and the compound containing a hydantoin ring comprises 5,5-dimethylhydantoin. 
     
     
         19 . The wastewater antimicrobial dispenser of  claim 16  wherein the biocidal metal is selected from the group consisting of a metallic silver alloy, pure silver or a substrate impregnated with metallic silver and the compound containing the hydantoin ring is either 5,5-dimethylhydantoin (DMH) Bromochlorodimethylhydantoin (BCDMH) or Dichlorodimethylhydatoin (DCDMH) or combinations thereof wherein the compound containing the hydantoin ring is either a powder, a liquid, a solid or combinations thereof. 
     
     
         20 . The wastewater antimicrobial dispenser of  claim 16  wherein the compound containing a hydantoin ring lacks biocidal effectiveness to kill microorganisms.