Treballs Finals de Grau d'Enginyeria Química, Facultat de Química, Universitat de Barcelona, Curs: 2015-2016, Tutores: María Esther Chamarro Aguilera i Cristina Valls VidalThis project is done in collaboration with the “Grup de recerca en Enginyeria Paperera
(Celbiotech)” of the Universitat Politècnica de Catalunya (UPC), which investigates new
methods for deinking recycled fibres, using biotechnological methods and ozone.
The main objective is to increase the use of fibres recycled from coloured paper. One of the
main problems of this raw material is the presence of contaminants, such as colourants, which
hinder its potential and causes the obtained product to loss part of its value. A big
inconvenience of using recycled fibres from the disintegration of coloured paper as raw material
is that the type of colourant used is unknown. Therefore, parameters based on measuring the
optical properties of the paper sheets where used to determine the efficiency of the colour
elimination sequences. The first part consisted in applying different enzymatic stages (laccasemediator
system) and a bleaching chemical agent to the red/black recycled fibres for
determining the efficiency of eliminating colour in the dough.
Afterwards, different biotechnological agents (enzymes) and chemical treatments will be
applied to the red recycled fibres using a combination of mediators and doubling the dose of
mediator used in the red fibres in order to determine which treatment gives the best results.
Later on, we will apply a selected colour elimination sequence to the red and black recycled
fibres, with the aim of determining the best biochemical sequence. At the same time, studies
with another oxidizing agent (ozone) will be done in order to determine if the enzymatic stages
can substitute the ozone stage.
Last part of the project consists in doing physical test to determine if the paper has lost any
of its properties after the treatments. The enzymatic activity of the effluents will be calculated as
well in order to determine which mediator performed better and the possibility of recirculating
these effluents will be studied