North Carolina State University

E.i. Dupont De Nemours and Company

The United States of America As Represented by the Secretary of

Hou-min Chang

Hasan Jameel

Thomas K Kirk

Bijan Amini

John Robert Webster

Thomas W Joyce

Bruce A Evans

Dingru Pan

Junfu Song

John A Heitmann, Jr

Tien-Wang Wu

David C Eaton

Geoffrey E Seger

Van-Ba Huynh

A process for treating a substrate, e.g., lignocellulosic pulp or cellulosic pulps, with a mixed peracid solution comprising percarboxylic acid and Caro's acid which results in a higher conversion rate of the active oxygen in the hydrogen peroxide in order to provide an inexpensive and effective delignification and/or bleaching solution and the process for making the mixed peracid solution.

Method of oxidatively treating a substrate with an equilibrium mixture

A process for treating a substrate, e.g., lignocellulosic pulp or cellulosic pulps with a mixed peracid solution comprising percarboxylic acid and Caro's acid which results in a higher conversion rate of the active oxygen in the hydrogen peroxide in order to provide an inexpensive and effective delignification and/or bleaching solution and the process for making the mixed peracid solution.

Process for preparing a bleaching liquor containing percarboxylic acid

Disclosed is a method of removing ink from xerographically printed paper. The method comprises pulping said printed paper in an aqueous slurry at a non-acidic pH to a consistency of about 8% or less. Next, added to the pulp slurry is a sufficient amount of long chain alcohol, the long chain alcohol having a melting point above room temperature, for a time sufficient with heating at a temperature sufficient, whereby an agglomeration of long chain alcohol and ink particles is formed. Next, the heating is stopped whereby the agglomeration solidifies into particles that settle to the bottom of the pulp slurry. Then, the agglomeration of solidified particles is removed from the pulp slurry thereby leaving a remaining slurry of deinked paper fiber and water. Optionally, the remaining slurry is subjected to flotation to remove substantially any remaining minute ink left particles behind after the agglomeration.

Deinking of xerographic printed wastepaper using long chain alcohol

A high-efficiency wood pulp bleaching process to produce wood pulps with higher brightness at equal chlorine dioxide usage or of equal brightness at significantly reduced chlorine dioxide usage. The process comprises reacting the chlorine dioxide with wood pulp at a pH of about 5-10 for about 5-40 minutes and then acidifying the mixture to a pH of about 1.9-4.2. The mixture is then allowed to react for about 2 or more hours to complete the two-step high/low pH bleaching process.

High efficiency two-step, high-low pH chlorine dioxide pulp bleaching

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.

Process of degrading chloro-organics by white-rot fungi

Pulp mill bleach plant caustic extraction effluent is decolorized using a primary or other sludge from a pulp and paper mill. The sludge is acidified and mixed with the effluent. After a short incubation period, the mixture of acidified sludge and effluent is raised to at least neutral pH, causing precipitation of most of the color in the effluent. The precipitated color may then easily be separated from the liquor by any conventional clarification technique. The method avoids the consumption of large quantities of expensive reagents or high transportation costs associated with the prior art decolorization techniques used on such effluent.

Growing community of inventors

Raleigh, NC, United States of America

Hou-min Chang