Method of Tracing Chemical Quantities Using Encapsulated Fluorescent Dyes

Abstract

The invention provides methods and compositions for utilizing encapsulated tracer dyes in difficult liquids such as wastewater or with highly reactive treatment chemicals such as aluminum-based coagulants. In difficult liquids or highly reactive treatment chemicals even so-called “inert” tracers end up reacting and their fluorescence changes. As a result they are inconsistent and cannot be used to measure the amount of treatment chemical present. But by encapsulating the tracer dyes, even non inert tracer dyes become inert and they can reliably be used to measure the amount of treatment chemical present even if highly reactive or in a difficult liquid.

1 - 17 . (canceled) 
     
     
         18 . A composition for tracing a treatment chemical, the composition comprising an encapsulated tracer comprising a mixture of at least one fluorescent dye and at least one nonionic surfactant, wherein an amount of the surfactant is greater than or equal to an amount of the fluorescent dye. 
     
     
         19 . The composition of  claim 18 , wherein the fluorescent dye has a fluorescent emission wavelength of 550 nm or more. 
     
     
         20 . The composition of  claim 18 , wherein the fluorescent dye is a xanthene derivative selected from the group consisting of rhodamine WT, sulforhodamine B, rhodamine B, and a combination thereof. 
     
     
         21 . The composition of  claim 18 , wherein the surfactant is a polymer. 
     
     
         22 . The composition of  claim 18 , wherein the surfactant is a multiblock co-polymer. 
     
     
         23 . The composition of  claim 18 , wherein the surfactant is a PEO-PPO-PEO tri-block co-polymer. 
     
     
         24 . The composition of  claim 18 , wherein the encapsulated tracer is formed by mixing the fluorescent dye with a melted form of dry surfactant to form a melted mixture, and cooling the melted mixture to form a solid mass. 
     
     
         25 . The composition of  claim 18 , wherein the encapsulated tracer is formed by dissolving the surfactant in water to form a surfactant solution, and then dissolve the fluorescent dye in the surfactant solution. 
     
     
         26 . The composition of  claim 18 , wherein the fluorescent dye and surfactant are at a ratio of from 1:20 to 3:10. 
     
     
         27 . A composition for tracing a treatment chemical, the composition comprising (a) an encapsulated tracer comprising at least one fluorescent dye and at least one non-ionic surfactant, (b) a treatment chemical selected from the group consisting of coagulants, flocculants, anti-scaling agents, and anti-corrosion agents, and (c) water. 
     
     
         28 . The composition of  claim 27 , wherein the encapsulated fluorescent tracer is at a concentration of at least about 50 ppb. 
     
     
         29 . The composition of  claim 27 , wherein the fluorescent dye is a xanthene derivative selected from the group consisting of rhodamine WT, sulforhodamine B, rhodamine B, and a combination thereof. 
     
     
         30 . The composition of  claim 27 , wherein the surfactant is non-ionic. 
     
     
         31 . The composition of  claim 27 , wherein the surfactant is a polymer. 
     
     
         32 . The composition of  claim 27 , wherein the encapsulated tracer is formed by mixing the fluorescent dye with a melted form of dry surfactant to form a melted mixture, and cooling the melted mixture to form a solid mass. 
     
     
         33 . The composition of  claim 27 , wherein the fluorescent dye and surfactant are at a ratio of from 1:20 to 3:10. 
     
     
         34 . The composition of  claim 27 , wherein the treatment chemical is a coagulant, a flocculant, or a combination thereof. 
     
     
         35 . The composition of  claim 27 , wherein the treatment chemical is an inorganic coagulant. 
     
     
         36 . The composition of  claim 27 , wherein the treatment chemical is an organic coagulant. 
     
     
         37 . The composition of  claim 27 , wherein the treatment chemical is a flocculant.