Process for biological deinking of office waste paper

Abstract

This invention relates to a biological process for deinking of office waste paper and more particularly, the present invention relates to a biological process for deinking of xerographic and inkjet printed paper using a gram-negative coccoid bacterium deposited at National Institute of Oceanography, Dona Paula, Goa 403 043, India having accession No. NIO/DI/32 and being deposited at an international depository ______ having accession number ______ and also deposited at Microbial Technology, Chandigarh, India having accession No. ______.

1 . A process for biological deinking of office waste paper inclusive of xerographic and inkjet-printed paper printed with non-impact and non-dispersible ink, said process comprises: 
 (a) growing coccoid bacterial isolate deposited at National Institute of Oceanography, Dona Paula, Goa 403 043, India having accession No. NIO/DI/32 and being deposited at an international depository ______ having accession number ______, in a nutrient broth containing beef extract, peptic digest of animal tissue and salinity ranging between 30 to 35 parts per thousand for at least 4 days;    (b) adding the resulting biomass of step (a) at 20% concentration to inoculate paper pulp diluted to at least 6% consistency suspended in sea water with salinity diluted to 50%;    (c) incubating the inoculated pulp for a minimum period of 96 hours followed by diluting the pulp tenfold;    (d) adding 1% by wt. of a surfactant and aerating for at least 10 minutes with compressed air to let the stray residual ink particles and contaminants flow out of the container, and    (e) filtering the pulp of step (d) over a funnel under suction, to get a sheet of pulp with uniform thickness and reading the brightness by radiance measurement.    
     
     
         2 . A process as claimed in  claim 1 , wherein in step (a), the bacterium is grown for a minimum of 4 days in nutrient broth containing beef extract and peptic digest of animal tissue in sea water with salinity diluted to 50%.  
     
     
         3 . A process as claimed in  claim 1 , wherein in step (b), the resulting bacterial biomass is concentrated by centrifugation and diluted to get final optical density of 1.0 measured at 660 nm in a spectrophotometer.  
     
     
         4 . A process as claimed in  claim 1 , wherein the diluted bacterial culture is inoculated to at least 6% pulp suspended in seawater with salinity diluted to 50% and incubated for a minimum period of 4 days within to completely beach the pulp.  
     
     
         5 . A process as claimed in  claim 1 , wherein the resulting bleached pulp is diluted tenfold, to which 1% surfactant is added, aerated using compressed air, and any free residual ink particles and contaminants are allowed to flow out of the solution.  
     
     
         6 . A process as claimed in  claim 1 , wherein after step (d) the xerographic or inkjet-printed paper is soaked in hot water for 1-2 hours and macerated after adding 1% surfactant to pulp.  
     
     
         7 . A process as claimed in  claim 6 , wherein the paper is macerated using conventional mixers.  
     
     
         8 . A process as claimed in  claim 1 , wherein in step (e), the washed pulp is filtered over a Buchner funnel under suction to get a pulp sheet of uniform thickness.  
     
     
         9 . A process as claimed in  claim 1 , wherein the pulp sheet is pressed at 60° C. for a minimum of 4-5 hours to make it uniform and dried.  
     
     
         10 . A process as claimed in  claim 1 , wherein the radiance of the resultant sheet is read from 412 to 684 nm and the radiance expressed as Lux units (LU) {wherein one LU is equivalent to μW/cm 2 /nm/Sr}.  
     
     
         11 . A process as claimed in  claim 1 , wherein the pulp sheet made out of recycled paper is used as a reference.  
     
     
         12 . A process as claimed in  claim 1 , wherein in steps (a) and (b), pure water containing 1.5% by wt of sodium chloride can be used in the place of sea water.