EFFECT OF LIGNIN ON THE ANAEROBIC DECOMPOSITION OF CELLULOSE AS DETERMINED THROUGH THE USE OF A BIOCHEMICAL METHANE POTENTIAL METHOD

A series of biochemical methane potential (BMP) tests was performed to determine the extent to which lignin and/or printing inks inhibit cellulose decomposition. Results indicated that the lack of cellulose decomposition in newspaper was not due to the presence of printing inks in the newspaper and was probably not a chemical effect (e.g., enzyme adsorption), but was related to the physical association between lignin and cellulose. Total cellulose decomposition in acid chlorite delignified newspaper and ballmilled newspaper ranged from 75% to 100%. By comparison, cellulose decomposition was limited to approximately 50% in untreated newspaper. Overall, the results from this study indicate that lignin significantly limits the amount of cellulose available for decomposition in newspaper. This suggests that under anaerobic conditions, newspapers will not completely degrade; hence, their apparent decomposition (or lack thereof) is not an appropriate indicator of biodegradation in sanitary landfills.