Abstract:
This research aimed to study the effects of cellulase enzyme and nonionic surfactant using Triton X-100 on flotation deinking of xerographic and laser-printed paper. The studied factors were flotation conditions, enzyme and surfactant dosages in the range of 0-0.15% and 0-1.2% (based on oven-dried pulp), respectively. The results showed that the increase of enzyme and surfactant dosages led to the decrease of ERIC (Effective Residual Ink Concentration) while freeness of pulp, brightness, tensile and tear index of tested handsheet increased. However, the excessive of surfactant and enzyme dosages tended to reduce the efficiency of ink removal and paper strength. The optimum condition for this deinking is the dosages of enzyme and surfactant of 0.1% and 0.9% (based on oven-dried pulp), respectively. On the environmental impact of enzyme deinking process, the result revealed that the effluent from this process has the chemical oxygen demand (COD) and acidity-alkalinity (pH) values in the accepted range of industrial effluent standards.