Optimum Condition of Cellulase Enzyme to Separate Aluminum Foil from Milk Carton (Tetra Pak)

Abstract

An experimental study was carried out to separate the 3 layers of
material that a UHT milk carton is composed of. The three layers are comprised of
polyethylene, paper and a sheet of aluminum.
The aim of this study was to separate these 3 layers using cellulase
enzymes. This study had 3 phases, the goal of phase 1 was to find the optimum
conditions necessary for the cellulase enzymes to separate the aluminum foil
from the other two layers of the milk carton. For the purposes of this study
“optimum” is defined as having four factors: enzyme loading, pH, stirring of the
enzyme, and temperature. Phase 2 was carried out to find the optimum
substrates per 1 g. cellulase and in phase 3 the concentration of glucose
present following the reaction had to be measured. The results for finding
optimum conditions in phase 1 are as follows, 1g enzyme, a pH of 6.8, the
optimum stirring rate was 150 rpm and the optimum temperature was 45°C. For
phase 2, the optimum substrates loading was 40 grams and in phase 3 the
glucose levels, following application of the cellulase, for 10, 20, 30, 40 and 50
gram milk cartons were 0.29 0.96 1.10 1.51 and 5.17 g/L, respectively.
The results of this study can be used as a guide in describing a
biological process to separate milk carton components. One of the major benefits of
this process is that it can reduce the equipment costs needed to recycle milk
cartons on an industrial scale.