Referências: O PAPEL vol. 74, num. 8, pp. 61 - 65 AUG 2013


ABSTRACT
Enzymatic deinking was performed by mean of common
commercial enzymes, whereas the neutral deinking is a process
achieved in a chemical environment that provides a pH of about 7.0,
and usually with application of only surface tension agents. This work
performs the deinking process in neutral conditions, with enzymatic
pretreatment of the waste paper pulp, and using ethoxylated fatty
acids as surfactant. The enzyme employed in the pretreatment is
cellulase or amylase, and the enzymatic activity for these enzymes
was evaluated according to IUPAC rules and based on temperature
and pH values, as by the supplier. This paper studied the influence
of HLB of surfactant in combined processes of enzymatic/neutral
deinking. These deinking processes are to cause less environmental
impact than the process commonly used in alkaline environment. It
studied the process in waste photocopy paper. For comparison, a pulp
without enzymatic pretreatment was used. The deinking enzymatic/
neutral process is carried out by flotation at a stock consistency of
0.8%, with a 6 minutes flotation phase at 40°C temperature. In the
deinking enzymatic/neutral process, the applied enzymes doses are
0.06%, 0.105% and 0.15%, and the ethoxylated fatty acids employed
of HLB are 12, 14 and 16. Optical properties were determined
as reflection factor at 457 nm (brightness ISO), not eliminating
measurement points. For waste photocopy paper the maximum
values of brightness ISO is 78.9% and 80.6% when cellulase and
amylase are used in enzymatic pretreatment, respectively.

Keywords: Enzymatic deinking, ethoxylated fatty acids, flotation,
neutral deinking, HLB value


Authors*: Hader H. Alzate Gil1
Andres Mauricio Dovale S.1
VirneyHadely Chala L.1
Oscar A. Muñoz2
Ana Elisa Casas B.2
German Camilo Quintana M.1
Jorge A. Velasquez J.1

*Authors’ references:
1. Group of Pulp and Paper - Universidad Pontificia Bolivariana. Colombia
2. Group Centre for Studies and Research in Biotechnology (CIBIOT) - Universidad Pontificia Bolivariana. Colombia
Corresponding author: Hader Humberto Alzate Gil - E-mail: hader.alzate@upb.edu.co