The paper aims to present the environmental impact of pulp and paper manufacturing and the most important production and control practices to minimizing this impact. The environmental consequences of manufacturing pulp and paper from pulping and bleaching processes are discussed in qualitative and quantitative terms. In these processes, sulfur compounds and nitrogen oxides are emitted to the air, and chlorinated and organic compounds and nutrients are discharged to the wastewaters. Large quantities of solid wastes and sludges are also generated.
In the last decades there has been a rapid evolution of techniques for production of bleached pulp. Much of these processes have been environmentally driven. New techniques have been developed in order to replace chlorine-based reagents in producing bleached pulp. Reducing the environmental impact of pulp production can be attain by using non-pollutant bleaching reagents like oxygen and related compounds. This paper deals with present findings and general trends in environmentally-sound chemical pulp bleaching. Most used environmentally-friendly reactants for pulp bleaching are presented emphasizing their role in a bleaching sequence. Oxygen, hydrogen peroxide, ozone, peracids and polyoxometalates are identified as among the most important reagents that can bleach pulp without affecting the environment. Environmentally-friendly pulp bleaching techniques which include a combination of oxygen, ozone, hydrogen peroxide and other non-chlorine chemicals are presented. Options for mill scale environmentallyfriendly pulp bleaching are included.
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