Determination of multi-valent metal contamination and system for removal of multi-valent metal contaminants from water

Abstract

A test for determining the presence of multi-valent metal contaminants, such as arsenic, mercury and chromium, when present in certain valence states and a system for removal of these contaminants from water. Multi-valent metal salts, for example, Cr +6 , which are highly toxic, can be detected and potentially removed from water through a redox reaction by reaction with iron or cobalt salts to obtain a reductive elimination of the Cr +6 by conversion to Cr +3 . The determination may be in the form of a test, such that a tableted composition can be introduced into water for reduction of a metal salt, such as Cr +6 to Cr +3 in order to provide a visual indication thereof. The system for the conversion of Cr +6 or other reducible metal salts to other lower valence states having less toxicity would rely upon introduction of a metal salt in the form of a reducing agent which would be introduced into the water allowing for a reduction/oxidation action to take place. This would be followed by removal of the flocculated/precipitated reduced contaminant metal salt and by re-reduction of the oxidized reducing agent.

1 - 38 . (canceled)  
     
     
         39 . A reaction system for reduction of content in a body of water of multi-valent, water-soluble metal contaminants which are reducible in the presence of a selected reducing agent, said system comprising: 
 a) a reaction volume containing a body of water to be treated for reducing the content of said harmful metal constituent;    b) means for introducing into said reaction volume a water-soluble, multi-valent metal reducing agent able to react with and effectively reduce the metal contaminant to a reduced valence state and simultaneously oxidize the reducing agent to a higher oxidized valence state;    c) means allowing for introduction into the body of water an ingredient which permits separation of any solid constituents formed in the body of water through reaction of the metal contaminant with the reducing agent; and    means for discharging and removing any separated solid constituents from the body of water.    
     
     
         40 . The reaction system for eliminating multi-valent metal contaminants from water of  claim 39  further characterized in that said metal contaminant is a contaminant which comprises a metal selected from the group consisting of arsenic, chromium and mercury or salts thereof.  
     
     
         41 . The reaction system for eliminating multi-valent metal contaminants from water of  claim 39  further characterized in that said reaction volume is contained in a reaction chamber.  
     
     
         42 . The reaction system for eliminating multi-valent metal contaminants from water of  claim 41  further characterized in that said chamber comprises a window through which to view an indication of the presence of the potentially harmful metal contaminant based on a visual change in a reaction medium therein.  
     
     
         43 . The reaction system for eliminating multi-valent metal contaminants from water of  claim 39  further characterized in that said reducing agent is a finely divided free metal or metal salt selected from the class consisting of iron and iron salts and cobalt and cobalt salts.  
     
     
         44 . The reaction system for eliminating multi-valent metal contaminants from water of  claim 39  further characterized in that said reducing agent is a metal or metal salt selected from the class consisting of cerium, cobalt, europium, iron, manganese, nickel, platinum, praseodymium, rhodium, samarium, terbium, tin, titanium, and ytterbium.  
     
     
         45 . The reaction system for eliminating multi-valent metal contaminants from water of  claim 39  further characterized in that said ingredient comprises a member selected from the class consisting of sequestering agents, precipitating agents and flocculating agents.  
     
     
         46 . The reaction system for eliminating multi-valent metal contaminants from water of  claim 45  further characterized in that said metal contaminates is a metal selected from the class consisting of arsenic, chromium, mercury or salts thereof, and that said reducing agent is a finely divided free metal or metal salt selected from the class consisting of iron and iron salts and cobalt and cobalt salts.  
     
     
         47 . A reaction system for reducing the amount of a water-soluble, multi-valent metal contaminant from water which is reducible in the presence of a selected reducing agent, said system comprising: 
 a) a reaction volume containing a body of water to be treated for reducing the amount of said harmful metal contaminant;    b) means for introducing into said reaction volume a water-soluble, multi-valent metal reducing agent able to react with and effectively reduce the metal contaminant to the reduced valence state and simultaneously oxidize the reducing agent to a higher oxidized valence state; and    c) introducing through said means for introducing a member selected from the class consisting of sequestering agents and flocculating agents and precipitating agents to collect any precipitated constituents in the body of water.    
     
     
         48 . The reaction system for eliminating multi-valent metal contaminants from water  claim 47  further characterized in that said system comprises a reactor detecting for presence of a member selected from the class consisting of arsenic, chromium or mercury or salts thereof.  
     
     
         49 . The reaction system for eliminating multi-valent metal contaminants from water of  claim 47  further characterized in that said metal-containing reducing agent is a member selected from the class consisting of iron and cobalt.  
     
     
         50 . The reaction system for eliminating multi-valent metal contaminants from water of  claim 47  further characterized in that said metal-containing reducing agent is a member selected from the class consisting of cerium, cobalt, europium, iron, manganese, nickel, platinum, praseodymium, rhenium, rhodium, samarium, terbium, tin, titanium, and ytterbium.  
     
     
         51 . The reaction system for eliminating multi-valent metal contaminants from water of  claim 47  further characterized in that said system comprises a dispersing agent to enable rapid dispersal of the reducing agent in the body of water.  
     
     
         52 . A reaction system for reduction of content in a body of water of multi-valent, water-soluble metal contaminants which are reducible in the presence of a selected reducing agent, said system comprising: 
 a) a reaction volume containing a body of water to be treated for reducing the content of said harmful metal constituent;    b) means for introducing into said reaction volume a water-soluble, multi-valent metal reducing agent able to react with and effectively reduce the metal contaminant to a reduced valence state and simultaneously oxidize the reducing agent to a higher oxidized valence state;    c) means allowing for introduction into the body of water an ingredient which permits separation of any solid constituents formed in the body of water through reaction of the metal contaminant with the reducing agent; and    d) means for maintaining said body of water at a pH substantially below 7.0.    
     
     
         53 . The reaction system for eliminating multi-valent metal contaminants from water of  claim 52  further characterized in that said metal contaminant which comprises a metal selected from the group consisting of arsenic, chromium and mercury, or salts thereof.  
     
     
         54 . The reaction system for eliminating multi-valent metal contaminants from water of  claim 52  further characterized in that said reaction volume is contained in a reaction chamber.  
     
     
         55 . The reaction system for eliminating multi-valent metal contaminants from water of  claim 54  further characterized in that said chamber comprises a window through which to view an indication of the presence of the potentially harmful metal contaminant based on a visual change in a reaction medium therein.  
     
     
         56 . The reaction system for eliminating multi-valent metal contaminants from water of  claim 52  further characterized in that said reducing agents is a finely divided free metal or metal salt selected from the class consisting of iron and iron salts and cobalt and cobalt salts.  
     
     
         57 . The reaction system for eliminating multi-valent metal contaminants from water of  claim 52  further characterized in that said reducing agent is a metal or metal salt selected from the class consisting of cerium, cobalt, europium, iron, manganese, nickel, platinum, praseodymium, rhodium, samarium, terbium, tin, titanium, and ytterbium.  
     
     
         58 . The reaction system for eliminating multi-valent metal contaminants from water of  claim 52  further characterized in that said ingredient comprises a member selected from the class consisting of sequestering agents, precipitating agents and flocculating agents.  
     
     
         59 . The reaction system for eliminating multi-valent metal contaminants from water of  claim 58  further characterized in that said metal contaminant in a metal selected from the class consisting of arsenic, chromium, mercury or salts thereof, and that said reducing agent is a finely divided free metal or metal salt selected from the class consisting of iron and iron salts and cobalt and cobalt salts.  
     
     
         60 . A reaction system for reducing the amount of a water-soluble, multi-valent metal contaminant from water which is reducible in the presence of a selected reducing agent, said system comprising: 
 a) a reaction volume containing a body of water to be treated for reducing the amount of said harmful metal contaminant;    b) means for introducing into said reaction volume a water-soluble, multi-valent metal reducing agent able to react with and effectively reduce the metal contaminant to the reduced valence state and simultaneously oxidize the reducing agent to a higher oxidized valence state; and    c) means for maintaining said body of water at a pH substantially below 7.0.    
     
     
         61 . The reaction system for eliminating multi-valent metal contaminants from water of  claim 60  further characterized in that the means for introducing in said system comprises means for introducing a member selected from the class consisting of sequestering agents and flocculating agents and precipitating agents to collect any precipitated constituents in the body of water.  
     
     
         62 . The reaction system for eliminating multi-valent metal contaminants from water of  claim 61  further characterized in that the means for introducing in said system comprises a dispersing agent in said body of water to enable fairly rapid dispersal of the reducing agent in the body of water.  
     
     
         63 . The reaction system for eliminating multi-valent metal contaminants from water  claim 60  further characterized in that selected from the class consisting detecting for presence of a member selected from the class consisting of arsenic, chromium or mercury or salts thereof.  
     
     
         64 . The reaction system for eliminating multi-valent metal contaminants from water of  claim 60  further characterized in that said metal-containing reducing agent is a member selected from the class consisting of iron and salt.  
     
     
         65 . The reaction system for eliminating multi-valent metal contaminants from water of  claim 60  further characterized in that said metal-containing reducing agent is a member selected from the class consisting of cerium, cobalt, europium, iron, manganese, nickel, platinum, praseodymium, rhenium, rhodium, samarium, terbium, tin, titanium, and ytterbium.  
     
     
         66 . A method for operating a reaction system for reduction of content in a body of water of multi-valent, water-soluble metal contaminants which are reducible in the presence of a selected reducing agent, said method comprising: 
 a) creating a reaction volume of the body of water to be treated;    b) introducing into said reaction volume a water-soluble, multi-valent metal reducing agent able to react with and effectively reduce the metal contaminant to a reduced valence state and simultaneously oxidize the reducing agent to a higher oxidized valence state;    c) introducing into the body of water an ingredient which permits separation of any solid constituents formed in the body of water through reaction of the metal contaminant with the reducing agent; and    d) discharging and removing any separated solid constituents from the body of water.    
     
     
         67 . The method for operating the reaction system of  claim 66  further characterized in that said metal contaminant is a contaminant which comprises a metal selected from the group consisting of arsenic, chromium and mercury or salts thereof.  
     
     
         68 . The method for operating the reaction system of  claim 66  further characterized in that said reaction volume is contained in a reaction chamber.  
     
     
         69 . The method for operating the reaction system of  claim 66  further characterized in that said chamber comprises a window through which view an indication of the presence of the potentially harmful metal contaminant based on a visual change in a reaction medium therein.  
     
     
         70 . The method for operating the reaction system of  claim 66  further characterized in that said reducing agent is a finely divided free metal or metal salt selected from the class consisting of iron and iron salts and cobalt and cobalt salts.  
     
     
         71 . The method for operating the reaction system of  claim 66  further characterized in that said reducing agent is a metal or metal salt selected from the class consisting of cerium, cobalt, europium, iron, manganese, nickel, platinum, praseodymium, rhenium, rhodium, samarium, terbium, tin, titanium, and ytterbium.  
     
     
         72 . The method for operating the reaction system of  claim 66  further characterized in that said ingredient comprises a member selected from the class consisting of sequestering agents, precipitating agents and flocculating agents.  
     
     
         73 . The reaction system for eliminating multi-valent metal contaminants from water of  claim 62  further characterized in that said metal contaminant is a metal selected from the class consisting of arsenic, chromium, mercury or salts thereof, and that said reducing agent is a finely divided free metal or metal salt selected from the class consisting of iron and iron salts and cobalt an cobalt salts.  
     
     
         74 . The method for operating the reaction system of  claim 66  further characterized in that said method comprises maintaining said water containing composition at a pH substantially below 7.0.