Fabrication of a laboratory scale flotation cell device for bio-deinking of waste papers

Fabrication of a cost effective, laboratory scale flotation device that can be used for deinking of various grades of wastepaper has been described. The unit consists of aeration device, sparger, baffies for high air to stock ratios and high shear mixing. The sparger is designed in such a way, that, it gives micro ·turbulent airflow necessary for removal of smaller ink particles. The deinking experiments using alkaline active cellulases from an alkalotolerant Fusarium sp have been reported. The enzyme preparation showed different cellulolytic and xylanolytic activities. Successful application of cellulases in enzymatic deinking of mixed office waste paper has been described. Recyclin g of waste paper into high-grade writing paper is th e new trend in paper industry. The major problem in recycling of waste paper is the removal of contaminants mainly the inks. Normally the ink contains non-polar pi gments or dyes and an agent that canies the ink to paper and facilitates in binding. These agents are typically water insoluble oils or polymers as in case of toners . Thus, their removal is not an easy process. Washing and flotation are two most commonly used methods of deinking. Other meth ods I ik e heat decolouri zation 1 , irradiation 2 , organi c solvent-based dei nking 3 , and magnetic deinking