North Carolina State University

Thomas W Joyce

Hou-min Chang

Thomas K Kirk

John A Heitmann, Jr

Larry S Jackson

Van-Ba Huynh

A method for making dissolving pulp from cellulosic fiber. The fiber is treated with a 3-stage sequence having a first alkali extraction stage, a xylanase treatment stage, and a second alkali extraction stage. Having the xylanase treatment stage sandwiched between 2 alkali extraction stages results in the dissolving pulp exhibiting both a very low xylan content of about 2.6% by weight or less and a very low mannan content of about 1.5% by weight or less. The low contents of these 2 components cannot be achieved with comparison treatments of only an alkali extraction stage, only a xylanase treatment stage, or only 2 stages of a xylanase treatment stage and an alkali extraction stage.

Method for making dissolving pulp from paper products containing hardwood fibers

A method of treating a felt to remove contaminants therein comprises the steps of providing a felt used in transporting paper webs, preparing an enzyme solution comprising an enzyme selected from the group consisting of a cellulase, a hemicellulase, and mixtures thereof, applying the enzyme solution to the felt for a first predetermined period of time, rinsing the felt with water, applying a solution of sodium hydroxide to the felt to remove the enzyme solution, and rinsing the felt with water to remove the sodium hydroxide solution thereby removing the contaminants in the felt.

Method of cleaning papermaking felts with enzymes

A process of treating effluent from a pulp or paper-making operation to decolorize the effluent is provided in which a white-rot fungus is germinated and grown and is then induced into a secondary metabolic state. The white-rot fungus is then immersed in the effluent where the fungus' active ligninolytic system decolorizes the effluent. The rate of fungal activity and the active lifetime of the fungus is increased by the addition to the effluent of at least one member of the class consisting of nutrient nitrogen, nutrient minerals, and a detergent.

Process of treating effluent from a pulp or papermaking operation

A process of degrading chloro-organics contained in liquid waste or effluent utilizes a white-rot fungus as the active ingredient in the chloro-organic degradation. The white-rot fungus is grown in the presence of certain nutrients including nutrient nitrogen and is then caused to enter a secondary metabolic state through nitrogen starvation. The fungus is then immersed in the liquid containing chloro-organics for a time period sufficient for the fungus to degrade the chloro-organics. At least periodically during the degradation period, the fungus is exposed to an oxygen enriched atmosphere. The efficacy and active lifetime of the fungus may be increased by the addition to the liquid of at least one member of the class consisting of nitrogen, a mixture of nutrient minerals, and a biological detergent.

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Raleigh, NC, United States of America

Thomas W Joyce