Chlorine Bleach Wood Pulp

These are toxic carcinogenic and recalcitrant to degradation.

Chlorine bleach wood pulp.

Elemental chlorine free ecf. Elemental chlorine free ecf is a technique that uses chlorine dioxide for the bleaching of wood pulp. For example the use of elemental chlorine in the bleaching of wood pulp produces organochlorines and persistent organic pollutants including dioxins. According to an industry group the use of chlorine dioxide in these processes has reduced the dioxin generation to under detectable levels.

Bleaching wood subtract color to add life. Two part bleach changes the actual color of wood and the other three remove stains. Chlorine dioxide ecf technology currently is the most important bleaching method worldwide. The process of doing it is called bleaching of wood pulp which is a chemical process.

It does not use elemental chlorine gas during the bleaching process and prevents the formation of dioxins and dioxin like compounds carcinogens. In the production of paper residual lignin from wood pulp is chemically liberated by using chlorine bleaching forming chlorinated lignin derivates such as chlorolignols. Traditionally the paper industry used chlorine gas to bleach pulp. In this process the wood pulp s color is enlightened and whiten.

Chlorine two part wood bleach oxalic acid and peroxide. It is used at moderately acidic ph 3 5 to 6. About 95 of all bleached kraft pulp is made using chlorine dioxide in ecf bleaching sequences. The use of chlorine dioxide minimizes the amount of organochlorine compounds produced.

Although preliminary surveys have detected dioxin in pulp mill wastes the scope of the problem is not yet known. For over four decades we have helped the industry navigate the changing landscape of bleaching technologies. Biobleaching is an important alternative to reduce the use of chlorine. As a core component of best available technique bat for production of pulp paper and board ecf bleaching will likely continue to dominate.

Chlorine dioxide serves as a bleaching agent for wood pulp and it is used because chlorine dioxide minimizes the amount of organochlorine compound that are produced in the process. Ecf is a pollution prevention technology recognized and accepted globally by such organizations as the united nations environment. Chlorine is commonly used as a bleach. Recently paper makers have begun using chlorine dioxide to bleach paper.

It has been found that bleaching can result in the formation of dioxin in the pulp when chlorine reacts with organic constituents of wood. Bleaching is done to whiten the paper which makes text on it easier to read the chlorine produces several by products including dioxins and furans. There are four types of bleach that woodworkers commonly use.