Magnesium thiosulfate as chlorine quencher and scrubber

Abstract

In one aspect, ozone is quenched from a water stream, such as a drinking water or wastewater stream being treated with ozone, by contacting the stream with magnesium thiosulfate. In another aspect, a method of scrubbing ozone from a gaseous stream comprises contacting the gaseous stream with magnesium thiosulfate. In an alternative embodiment, chlorine is quenched from a water stream by contacting the stream with magnesium thiosulfate or potassium thiosulfate. In yet another aspect, a method of scrubbing chlorine from a gaseous stream comprises contacting the stream with magnesium thiosulfate or potassium thiosulfate. In another embodiment, a thiosulfate, such as magnesium thiosulfate, calcium thiosulfate, potassium thiosulfate, or sodium thiosulfate, is provided on an air filter for scrubbing ozone or chlorine from gaseous streams.

1 .- 9 . (canceled) 
   
   
       10 . A method of quenching chlorine from a water stream containing chlorine comprising contacting the water stream with magnesium thiosulfate or potassium thiosulfate under conditions sufficient to quench chlorine from the water stream. 
   
   
       11 . The method of  claim 10  wherein the water stream comprises drinking water. 
   
   
       12 . The method of  claim 10  wherein the water stream comprises wastewater. 
   
   
       13 . The method of  claim 10  wherein magnesium thiosulfate is contacted with the water stream at a chlorine to magnesium thiosulfate mole ratio of from about 1.5:1 to about 3.5:1. 
   
   
       14 . The method of  claim 13  wherein the chlorine to magnesium thiosulfate mole ratio is from about 2:1 to about 2.5:1. 
   
   
       15 . A method of scrubbing chlorine from a gaseous stream containing chlorine comprising contacting the gaseous stream with magnesium thiosulfate or potassium thiosulfate under conditions sufficient for scrubbing chlorine from the gaseous stream. 
   
   
       16 . The method of  claim 15  wherein the gaseous stream comprises air and treatment system plant off-gas. 
   
   
       17 . The method of  claim 15  wherein magnesium thiosulfate is contacted with the gaseous stream at a chlorine to magnesium thiosulfate mole ratio of from about 1.5:1 to about 3.5:1. 
   
   
       18 . The method of  claim 17  wherein the chlorine to magnesium thiosulfate mole ratio is from about 2:1 to about 2.5:1. 
   
   
       19 . An air filter comprising a thiosulfate in an amount effective for scrubbing chlorine from a gaseous stream. 
   
   
       20 . The air filter of  claim 19  wherein the thiosulfate is selected from the group consisting of magnesium thiosulfate, calcium thiosulfate, potassium thiosulfate, and sodium thiosulfate. 
   
   
       21 . The method of  claim 15  wherein potassium thiosulfate is contacted with the gaseous stream at a chlorine to potassium thiosulfate mole ratio of from about 1.5:1 to about 3.5:1. 
   
   
       22 . The method of  claim 21  wherein the chlorine to potassium thiosulfate mole ratio is from about 2:1 to about 2.5:1. 
   
   
       23 . The method of  claim 15  wherein the gaseous stream is passed through a filter containing magnesium thiosulfate or potassium thiosulfate. 
   
   
       24 . The method of  claim 16  wherein the gaseous stream is passed through a filter containing magnesium thiosulfate or potassium thiosulfate.