Decolorization of concentrated rhamnolipid composition

Abstract

Provided is a method for decolorizing and optionally neutralizing a rhamnolipid composition comprising treating said composition with a percarbonate salt as well as the decolorized and optionally neutralized composition obtainable therefrom. Also provided is a method for improving the quality of wastewater generated during said method.

What is claimed is: 
     
         1 . An organic solvent-free process for obtaining a neutralized composition comprising one or more rhamnolipids (RLs) comprising:
 (a) providing an aqueous medium comprising at least one rhamnolipid;   (b) treating said medium provided with acid to obtain an acidic medium comprising a solid, liquid and oily phase;   (c) removing at least the liquid phase from said acidic medium of (b) to obtain an acidic solid phase and optionally acidic oily phase;   (d) treating said acidic solid phase and optionally acidic oily phase obtained in (c) with a composition comprising a percarbonate salt in an amount effective to neutralize and decolorize said acidic solid phase and optionally said acidic oil phase of step (c) to obtain said neutralized composition.   
     
     
         2 . The method according to  claim 1 , wherein said neutralization and decolorization step occurs at a temperature of between about 35-85C for at least about 30 minutes. 
     
     
         3 . The method according to  claim 1 , wherein said composition in step (d) further comprises a second base. 
     
     
         4 . The method according to  claim 1 , wherein said percarbonate salt in step (d) is present in the amount of about 0.5 to about 3% equivalent hydrogen peroxide concentration (EHPC). 
     
     
         5 . A composition comprising a neutralized and decolorized solution obtainable according to the method of  claim 1 . 
     
     
         6 . A method for increasing the quality of the liquid phase obtained in step (b) of the process of  claim 1 , comprising treating said liquid phase with an amount of percarbonate salt effective to increase said quality. 
     
     
         7 . A method of reducing the BOD and/or TSS of at least about 25% in the liquid phase obtained in the process of  claim 1 , comprising treating said liquid phase with a composition comprising a percarbonate salt in an amount effective to reduce BOD and/or TSS of at least about 25% in said liquid phase. 
     
     
         8 . The method according to  claim 7 , wherein said percarbonate salt is present in an amount of about 0.2% to about 0.8% w/w EHPC.