Proof

Paper is one of the most common natural resources we used in everyday life. The invention of paper allowed human to record knowledge and spread information rapidly. In modern world, the enormous amount of paper usage is decreasing the tree density around the globe. Paper reuse is a strategy of reducing tree cut, but recycling paper isn’t an easy job. Paper are made of different fibers depending on the manufacturing process, and printed with different inks. These reasons increase the difficulty of turning the pulp clean and ready for use. Deinking is the process which separates the ink and paper fiber during the cleanup of reprocessed paper pulp. The deinking process in the industry use chemical reagents like detergent, alkali which would cause water pollution and air pollution. Our plan is to replace the chemical reagents with biological enzymes, turning the waste into an environmentally friendly organic compound. We are going to create a controllable enzyme secrete system which would extend the limit of deinking and be more eco-friendly.

Reprocessing paper is very important for reducing deforestation, but the current manufacturing process causes chemical pollution and substantial paper fiber losses. After extensive discussions with paper-making experts, we have devised a plan to replace the chemicals used in traditional paper reprocessing and to increase recovery of paper fibers. In our model, the paper sheets undergo image analysis to determine which spots have ink printed on top and will be sprayed with Saccharomyces cerevisiae which has been engineered to express deinking enzymes upon light induction. Instead of treating all paper pulp, only the spots with ink is shone with light to induce localized deinking. This procedure can remove ink efficiently while protecting most of the paper fibers from being digested. This design extends the lifetime of the paper fibers and reduces wood-logging for making paper.