Enzymatic Deinking In Waste Paper Pulping

Waste paper is a very important renewable resource, recycling of waste paper is aneffective way to solve the problem that the paper industry is facing now, such asshortage of raw materials, energy shortages and pollution. Athougth the technology ofrecycling waste paper has matured, there are still many problems need to be solved.Because of the secondary reuse of the fiber, the strength and binding capacity of fiberdecreased, the ablity of filtration decreased too, which cause a great impact to the papermachine operation and product quality. With advances in technology, biotechnology asan emerging technology has been widely used in the paper industry, people hope thatthrough biological enzyme deinking and secondary fiber modified technology toimprove product quality, reduce pollution and decrease costs.Enzymatic modification of waste pulp fiber has broad prospects, but theunderstanging of enzymes and the rule of pulp reaction need to be futher improved. Themain contents of this research are depicted as follow:The situation of paper industry, recycling and utilization of waste paper, enzymaticdeinking in waste paper pulping and the mechanism of enzymatic deinking weredepicted in the first chapter, which provide an effective theoretical guarantee for thelater experiment.In order to improve the efficiency of enzyme in the processing of pulp, enzymeactivity and biological charactrization of enzyme were measured in the second chapter.Chapter III is main to study the process of enzymatic deinking of mixed officewaste paper, the optimal conditions for cellulase enzyme, hemicellulase enzyme,alkaline lipase enzyme and pectinase enzyme deinking have been preliminary identified.The fourth chapter studies the papermaking performance of different biologicalenzyme deinked pulp, choosing cellulase enzyme, hemicellulase enzyme, alkaline lipaseenzyme and pectinase enzyme to deink the same waste pulp, then comparison of thechanges of paper performance, obtained the biological enzyme deinked pulp whichpossesses the best papermaking properties.The last chapter discusses the impact of surfactants onthebio-enzymatic deinkingeffect, compaison of the deink effect of different surfactants combined with enzyme.The paper combines the theory of enzymatic knowledge and papermaking, has gave a preliminary analysis and discussion on the reasons of the papermakingperformance differences between different enzyme deinked pulp. The study shows thatthe best process for the enzymatic de-inking of mixed office waste is that, use theAEO-9with alkaline lipase deinking of mixed office waste, thebest dosage of AEO-9is0.75%, the best pulp concentration is8%, pH value is8.5, temperature is30oC, the bestprocessing time is40min, and the best amount of alkaline lipase enzyme is3U/g...