Environmental, Health, and Safety Guidelines

 

PULP AND PAPER MILLS 

                                                              

 

D

ECEMBER 

10,

 

2007 

              

   

 

 

                      

3 

 

                                     

 

 

  

 WORLD BANK GROUP 

•

 

Dry debarking of wood; 

•

 

Systems for collection and recycling of  temporary and 

accidental discharges from process water spills;  

•

 

Sufficient and balanced volumes of pulp storage, broke 

storage and white water storage tanks to avoid or reduce 
process water discharges; 

•

 

Recycling of wastewater, with or without simultaneous 

recovery of fibers (using filters or flotation plants); 

•

 

Separation of contaminated and non-contaminated (clean) 

wastewaters with collection and reuse of clean non-contact 

cooling waters and sealing waters;   

•

 

Potentially contaminated stormwater includes runoff from 

log and wood handling areas, process equipment, building 

roofs and areas immediately around the mill process areas.  

This should be combined with process effluent  for 

treatment. 

Guidance applicable to the management of cooling water, and 

additional guidance applicable to stormwater, is presented in the 

General EHS Guidelines.   

Wastewater Management – Kraft and Sulfite Pulp Mills  
Additional recommended wastewater prevention and control 

methods for Kraft and sulfite mills include the following: 

•

 

Oxygen delignification ahead of the bleach plant; 

•

 

Efficient washing of the pulp ahead of the bleaching (Kraft 
and sulfite mills); 

•

 

Decreasing or eliminating the formation of 2,3,7,8-TCDD 

and 2,3,7,8-TCDF in wood and non-wood bleaching 

processes by

4

:  

o

 

Replacement of elemental chlorine bleaching with 

elemental chlorine free (ECF) bleaching

5

 or total 

chlorine free (TCF) bleaching 

                                                 

4

 UNEP, 2006.  

o

 

Reducing application of elemental chlorine by 

decreasing chlorine multiple or increasing the 

substitution of chlorine dioxide for molecular chlorine  

o

 

Minimizing precursors such as dibenzo-p-dioxin and 

dibenzofuran entering the bleach plant by using 

precursor-free additives and thorough washing; 

o

 

Maximize knot removal  

o

 

Eliminating pulping of furnish contaminated with 

polychlorinated phenols 

•

 

Removal of hexenuronic acids by mild hydrolysis for 
hardwood pulp, especially eucalyptus;  

•

 

Collection and recycling of spent cooking liquor spills; 

•

 

Stripping and reuse of evaporation and digester 

condensates in order to reduce odor producing total 

reduced sulfur (TRS) compounds (Kraft and sulfite mills). 

•

 

Neutralization of spent cooking liquor before evaporation 

and reuse of condensate in order to reduce dissolved 

organics (Sulfite mills);  

•

 

Including chemical recovery in sulfite as well as Kraft mills.   

 

Wastewater Management – Mechanical and Chemi-
mechanical Mills  
Additional recommended wastewater prevention and control 

methods for mechanical and chemi-mechanical mills include the 

following: 

•

 

Minimizing reject losses; 

•

 

Maximizing water recirculation in mechanical pulping 

process; 

•

 

Application of thickeners to effectively separate water 

systems from the pulp and paper mills; 

                                                                               

5

 

ECF bleaching requires on-site manufacture of chlorine dioxide (ClO

2

).  The 

ClO

2 

process chosen should have low production of chlorine as a by -product of 

ClO

2 

production.