IV Iberian Congress on Biotechnology; I Ibero-American Meeting on Biotechnolog

Amaral-Collaço, M. T.

Gama, F. M.

Gírio, F. M.

Mota, M.

Pala, H.

Universidade do Minho: RepositoriUM

BIOTEC’98 AB063 75 Preliminary studies on enzymatic deinking  Pala, H.1; Gama, F.M.1; Gírio, F.M.2; Amaral-Collaço, M.T.2; Mota, M.1 1Centro de Engenharia Biológica - IBQF, Universidade do Minho, 4700 Braga, Portugal 2Unidade de Microbiologia Industrial e Bioprocessos, Departamento de Biotecnologia IBQTA, INETI, Azinhaga dos Lameiros, 1699 Lisboa Codex PORTUGAL  Key words: wastepaper, recycling, deinking, enzymes   Wastepaper recycling is nowadays mandatory, because of the world-wide lack of virgin fibre, and in order to reduce the cellulosic residues produced in developed societies. The incorporation of secondary fibres in paper production became an accepted reality, and research on recycling technologies, namely for effective removal of pulp contaminants (deinking) is necessary. Traditional processes use expensive, potentially environment damaging chemicals. An alternative to these methods are biological treatments, which use enzymes to peel away cellulosic fibrils, thus removing attached ink particles which are then removed by flotation [1]. Enzymatic technology is also known as specially advantageous to deink mixed office waste (MOW), the best quality wastepaper. The reuse of MOW is usually limited by its high content of noncontact inks, which are very difficult to remove by application of current methodologies [2]. The current work aims to study the potential of enzymes in the deinking of three different wastepaper samples: (i) photocopy printed paper; (ii) MOW (a chemically treated pulp); (iii) newspaper (a mechanical pulp). The enzymatic cocktail used was a commercial preparation kindly supplied by Buckman Laboratories, which presents mainly cellulase and xylanase activities. Enzymatic action on pulp was conveniently evaluated by determining physical, mechanical and optical properties of pulp and paper, according to the standard TAPPI procedures. Parameters as drainage rate, burst, tensile, tear and brightness were measured. Image analysis techniques were also used, allowing the study of the enzyme treatment on ink particles size distribution. The obtained results revealed the effectiveness of the assayed enzyme preparation on ink removal trials, with the three tested pulp samples. However, enzymatic deinking requires special conditions such as pH value, pulping consistency, soaking and reaction times, mechanical shear forces and refining mixed effects (with the enzymes), which will be analysed in further work.  [1] Jeffries, T., Klungness, J.H., Sykes, M., Rutledge-Cropsey, K., TAPPI 1993 Recycling Symposium, 183 - 188, 1993 [2]Prasad, D.Y., Appita, 46 (4), 289 - 292, 1993 

Preliminary studies on enzymatic deinking

Pala, Helena

Gama, Francisco Miguel

Gírio, Francisco M.

Mota, Manuel

IC-online

BIOTEC’98 AB063 
75 
Preliminary studies on enzymatic deinking 
 
Pala, H.1; Gama, F.M.1; Gírio, F.M.2; Amaral-Collaço, M.T.2; Mota, M.1 
1Centro de Engenharia Biológica - IBQF, Universidade do Minho, 4700 Braga, Portugal 
2Unidade de Microbiologia Industrial e Bioprocessos, Departamento de Biotecnologia 
IBQTA, INETI, Azinhaga dos Lameiros, 1699 Lisboa Codex PORTUGAL 
 
Key words: wastepaper, recycling, deinking, enzymes 
 
 
Wastepaper recycling is nowadays mandatory, because of the world-wide lack of virgin fibre, and 
in order to reduce the cellulosic residues produced in developed societies. The incorporation of 
secondary fibres in paper production became an accepted reality, and research on recycling 
technologies, namely for effective removal of pulp contaminants (deinking) is necessary. 
Traditional processes use expensive, potentially environment damaging chemicals. An alternative to 
these methods are biological treatments, which use enzymes to peel away cellulosic fibrils, thus 
removing attached ink particles which are then removed by flotation [1]. Enzymatic technology is 
also known as specially advantageous to deink mixed office waste (MOW), the best quality 
wastepaper. The reuse of MOW is usually limited by its high content of noncontact inks, which are 
very difficult to remove by application of current methodologies [2]. 
The current work aims to study the potential of enzymes in the deinking of three different 
wastepaper samples: (i) photocopy printed paper; (ii) MOW (a chemically treated pulp); (iii) 
newspaper (a mechanical pulp). The enzymatic cocktail used was a commercial preparation kindly 
supplied by Buckman Laboratories, which presents mainly cellulase and xylanase activities. 
Enzymatic action on pulp was conveniently evaluated by determining physical, mechanical and 
optical properties of pulp and paper, according to the standard TAPPI procedures. Parameters as 
drainage rate, burst, tensile, tear and brightness were measured. Image analysis techniques were 
also used, allowing the study of the enzyme treatment on ink particles size distribution. 
The obtained results revealed the effectiveness of the assayed enzyme preparation on ink removal 
trials, with the three tested pulp samples. However, enzymatic deinking requires special conditions 
such as pH value, pulping consistency, soaking and reaction times, mechanical shear forces and 
refining mixed effects (with the enzymes), which will be analysed in further work. 
 
[1] Jeffries, T., Klungness, J.H., Sykes, M., Rutledge-Cropsey, K., TAPPI 1993 Recycling 
Symposium, 183 - 188, 1993 
[2]Prasad, D.Y., Appita, 46 (4), 289 - 292, 1993 


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Preliminary studies on enzymatic deinking

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