文档介绍：Pulp and paper industry water treatment
This two kinds of industries are normally separated. The pulp (raw material for paper industry)
and the paper industry, produce different kind of waste water. There is also a third related
industry, the paper recycling industry, which has a similar kind of waste water. In the following
text the three branches of industry are separated.
Production process, pulp industry
position of pollutants in waste water of paper industries, depend on the kind of raw
material which is used. For paper production wood, bagasse (outer stalk sugar cane), hemp,
straw, etc. are used. Five basic procedures are used to produce pulp in an industrial way. The
conduction of case can be with or without a bleaching process.
If a bleaching process is also step of production, the Lignin will be destroyed. The effect is a
whiter paper. The color depends also on the different kinds of wood or other raw materials which
are used for the production. This step have the disadvantage to load the environment more,
because of the use of chemicals like chlorine or chlorine dioxide (which are restricted, because of
the process).
Chemical Processes
To produce pulp for fine and print paper, two chemical procedures are used.
The Kaft process is an alkaline process. The lignin is cracked by NaOH or Na2S, which is very
effective at di