Page 139 - Membranes for Industrial Wastewater Recovery and Re-Use

Industrial waters 11 3

Recovered paper loads the water circuit of paper mills with a variety of
adhesives. Colloidal, dissolved, finely dispersed or water-soluble adhesives
originating from recovered fibre are called secondary stickies because they
agglomerate only later in the finished stock through chemical reaction, or else
they appear only on the paper machine thus causing severe problems. In
addition, the alkaline de-inking procedure and a high temperature promote
dissolution of adhesives in the circulation water (Zippel, 2001). It has been
estimated that the total amount of adhesives in DIP (de-inked pulp) is 7 kg/t of
paper, 70 times the maximum permitted level of sticky material allowed in white
paper manufactured from DIP (0.1 kg/t; Zippel, 2001). Volume and quality data
for water from stock preparation of different paper grades using recovered fibre
areshowninTable 3.15.

3.2.4 Current water and effluent purification systems and governing legislation
Driving forces for effluent treatment in the pulp and paper industry can be
categorised as follows:
0 Environmental legislation
0 Better economy
0 Local demands, for example lack of water resources
0 Customer demand

The environmental legislation in the pulp and paper industry is likely to
undergo profound changes within the next few years. The EU Directive on
Integrated Pollution Prevention and Control (IPPC) includes a BAT reference
document, BREF, which refers to the pulp and paper industry. This came into
force in 1999 for greenfield mills, and will apply to existing mills from 2007. The

Table 3.15 Emission levels for stock preparation of different paper grades using recovered
paper (EIPPCB, 2001)
Recovered paper Waterflow TSS COD AOX
quality (m3/tpaper) (mg/l) (Wt, rng/l) (pit. mg/U
Packaging paper Sorted mixed paper and 0-4 Below 200 27-36.6750-9000 < 4.1
boars, recovered paper
from stores
Newsprint De-inkable recovered 8-1 6 Below 200 17-27,1700-2700 < 10,l
paper (50:50 newsprint
and magazines)
LWC/SC paper De-inkable recovered 8-16 Below 200 17-27,1700-2700 < 10,l
paper (5O:SO newsprint
and magazines)
Tissue paper and De-inkable recovered 8-1 6 Below200 26-35.2600-3500 <lo, 1
market pulp paper (50:SO newsprint
and magazines):
wood-free office
recovered paper