Bleaching Process for Minimising AOX Discharges, 1992 Environmental Conference Proceedings
A concept has been explored in which the organo-chlorine compounds generated in one stage of a bleaching sequence are destroyed in following sections of the process. Laboratory experimentation on eucalypt kraft pulp has demonstrated that full brightness may be achieved without deleterious effects on pulp strength and optical properties while reducing the discharge of these organo-chlorine compounds to levels well below those currently achievable in conventional bleach plants.
The concept is accomplished in practice by not washing the pulp between the ’chlorination’ stage and the alkaline extraction stage. Extraction and chemical dechlorination of organo-chlorine compounds occur simultaneously. The process may or may not be molecular chlorine free.
Bleaching Process for Minimising AOX Discharges, 1992 Environmental Conference Proceedings