Effects of cellulase enzyme in deinking of Solvent-Based inks from mixed office wastes

The effects of cellulase enzymes (Trichoderma reesei) in flotation deinking of mixed office wastes (MOW) on the deinking efficiency, physical and optical properties of the papers were investigated. In order to determine the effects of cellulase, conventional chemical deinking was also performed and compared with enzymatic deinking. After deinking processes, the handsheets were produced to determine deinking efficiency and physical and optical properties. Dirt particle analyses, Effective Residual Ink Concentrations (ERIC) and deinking efficiency (IEERIC) were determined to clearly understand effects of cellulase on deinking of MOW. IEERIC values of papers obtained from enzymatic and chemical deinked pulps were 11.9 and 62.0%, respectively. Use of cellulase enzyme by itself was not as effective as conventional deinking. Furthermore, optical properties of enzymatic deinked papers were lower than those of chemical deinked papers. These negations were eliminated by combining enzymatic and chemical deinking processes. Chemical charge used in conventional deinking were reduced by half with using cellulase. Properties of papers obtained from this deinking process were better than both enzymatic and chemical ones. This suggests that using cellulase enzyme in deinking process of MOW have a great potential as an alternative to chemical conventional deinking per se.