Methods, compositions and systems for controlling fouling of a membrane

Abstract

The present invention provides methods and compositions for improving permeability and flux in a membrane filtration system, especially in water or wastewater treatment processes.

1 . A method of improving the permeability of a membrane used in a process or the flux through
 a membrane used in a process, comprising subjecting the membrane to one or more microorganisms capable of reducing or preventing undesirable biofilm formation on the membrane.   
     
     
         2 . The method of  claim 1 , wherein microorganisms includes one or more bacterial strains capable of reducing or preventing undesirable biofilm formation on the membrane. 
     
     
         3 . The method of  claim 1 , wherein the one or more microorganisms are spore forming microorganisms capable of reducing or preventing undesirable biofilm formation on the membrane. 
     
     
         4 . The method of  claim 2 , wherein the one or more bacterial strains are spore forming bacterial strains capable of reducing or preventing undesirable biofilm formation on the membrane. 
     
     
         5 . The method of  claim 1 , wherein microorganisms includes one or more bacterial strains, one or more fungal strains, or a mixture of one or more bacterial and fungal strains capable of reducing or preventing undesirable biofilm formation on the membrane. 
     
     
         6 . The method of  claim 1 , wherein the membrane is subjected to a strain of  Bacillus  spp., e.g.,  Bacillus amyloliquefaciens; Bacillus atrophaeus; Bacillus azotoformans; Bacillus brevis; Bacillus cereus; Bacillus circulans; Bacillus clausii; Bacillus coagulans; Bacillus firmus; Bacillus flexus; Bacillus fusiformis; Bacillus globisporus; Bacillus glucanolyticus; Bacillus infermus; Bacillus laevolacticus; Bacillus licheniformis; Bacillus marinus; Bacillus megaterium; Bacillus mojavensis; Bacillus mycoides; Bacillus pallidus; Bacillus parabrevis; Bacillus pasteurii; Bacillus polymyxa; Bacillus popiliae; Bacillus pumilus; Bacillus sphaericus; Bacillus subtilis; Bacillus thermoamylovorans ; or  Bacillus thuringiensis.    
     
     
         7 . The method of  claim 1 , wherein the improved flux allows for the use of a membrane having a smaller membrane surface area. 
     
     
         8 . The method of  claim 1 , wherein the membrane is part of a membrane bioreactor system. 
     
     
         9 . The method of  claim 1 , wherein the process is a water treatment process. 
     
     
         10 . The method of  claim 1 , wherein the one or more microorganisms are capable of preventing or reducing biofilm formation through quorum sensing inhibition. 
     
     
         11 . The method of  claim 6 , wherein the one or more strains of  Bacillus  are selected from the group consisting of:
 the  Bacillus megaterium  strain having the deposit accession number ATCC 14581;   the  Bacillus pumilus  strain having the deposit accession number ATCC 700385;   the  Paenibacillus azotofixans  strain having the deposit accession number ATCC 35681;   the  Bacillus licheniformis  strain having the deposit accession number NRRL B-50014;   the  Bacillus licheniformis  strain having the deposit accession number NRRL B-50015;   the  Bacillus pumilus  strain having the deposit accession number NRRL B-50016;   the  Bacillus subtilis  strain having the deposit accession number ATCC 6051A;   the  Bacillus amyloliquefaciens  strain having the deposit accession number NRRL B-50017;   the  Bacillus amyloliquefaciens  strain having the deposit accession number NRRL B-50018;   the  Bacillus subtilis  strain having the deposit accession number NRRL B-50136;   the  Bacillus amyloliquefaciens  strain having the deposit accession number NRRL B-50141;   the  Bacillus amyloliquefaciens  strain having the deposit accession number NRRL B-50304;   the  Bacillus amyloliquefaciens  strain having the deposit accession number NRRL B-50349;   the  Bacillus megaterium  strain having the deposit accession number PTA-3142;   the  Bacillus amyloliquefaciens  strain having the deposit accession number PTA-7541;   the  Bacillus amyloliquefaciens  strain having the deposit accession number PTA-7542;   the  Bacillus atrophaeus  strain having the deposit accession number PTA-7543;   the  Bacillus amyloliquefaciens  strain having the deposit accession number PTA-7544;   the  Bacillus amyloliquefaciens  strain having the deposit accession number PTA-7545;   the  Bacillus amyloliquefaciens  strain having the deposit accession number PTA-7546;   the  Bacillus subtilis  strain having the deposit accession number PTA-7547;   the  Bacillus amyloliquefaciens  strain having the deposit accession number PTA-7549;   the  Bacillus amyloliquefaciens  strain having the deposit accession number PTA-7790;   the  Bacillus amyloliquefaciens  strain having the deposit accession number PTA-7791;   the  Bacillus  atrophaeus strain having the deposit accession number PTA-7792; and   the  Bacillus amyloliquefaciens  strain having the deposit accession number PTA-7793; or a mixture of two or more of the strains.   
     
     
         12 . A method of increasing critical flux of a membrane used in a process, comprising subjecting the membrane to one or more microorganisms capable of reducing or preventing undesirable biofilm formation on the membrane. 
     
     
         13 . The method of  claim 12 , wherein microorganisms includes one or more bacterial strains, capable of reducing or preventing undesirable biofilm formation on the membrane. 
     
     
         14 . The method of  claim 12  wherein the one or more microorganisms are spore forming microorganisms capable of reducing or preventing undesirable biofilm formation on the membrane. 
     
     
         15 . The method of  claim 13  wherein the one or more bacterial strains are spore forming bacterial strains capable of reducing or preventing undesirable biofilm formation on the membrane. 
     
     
         16 . The method of  claim 12 , wherein microorganisms includes one or more bacterial strains, one or more fungal strains, or a mixture of one or more bacterial and fungal strains capable of reducing or preventing undesirable biofilm formation on the membrane. 
     
     
         17 . The method of  claim 12 , wherein the membrane is part of a membrane bioreactor system. 
     
     
         18 . The method of  claim 12 , wherein the process is a water treatment process. 
     
     
         19 . A method of reducing or preventing fouling of a membrane used in a process, comprising subjecting the membrane to one or more microorganisms capable of reducing or preventing undesirable biofilm formation on the membrane. 
     
     
         20 . The method of  claim 19 , wherein microorganisms includes one or more bacterial strains capable of reducing or preventing undesirable biofilm formation on the membrane. 
     
     
         21 . The method of  claim 19 , wherein the one or more microorganisms are spore forming microorganisms capable of reducing or preventing undesirable biofilm formation on the membrane. 
     
     
         22 . The method of  claim 20 , wherein the one or more bacterial strains are spore forming bacterial strains capable of reducing or preventing undesirable biofilm formation on the membrane. 
     
     
         23 . The method of  claim 19 , wherein microorganisms includes one or more bacterial strains, one or more fungal strains, or a mixture of one or more bacterial and fungal strains capable of reducing or preventing undesirable biofilm formation on the membrane. 
     
     
         24 . The method of  claim 19 , wherein the membrane is part of a membrane bioreactor system. 
     
     
         25 . The method of  claim 19 , wherein the process is a water treatment process. 
     
     
         26 . The method of  claim 19 , wherein the one or more microorganisms are capable of preventing or reducing biofilm formation through quorum sensing inhibition.