Significant indicators of water quality 



The quality characteristics of untreated surface 

 \yaters used by the pulp and paper industry are 

 given in table V-9. Treatment of the raw water 

 should provide water to the process with the qual- 

 ity requirements described in table V-10. Process 



TABLE V-9. Quality Characteristics of Surface 



Waters That Have Been Used by the Pulp and 



Paper Industry (SIC 26) 



[Unless otherwise indicated, units are mg/l and values are 



maximums. No one water will have all the maximum 



values shown.] 



Chemical pulp and paper 



Characteristics 



Mechanical 

 pulping Unbleached Bleached 



Silica (SiOs) C) 50 50 



Aluminum (Al) C) O C) 



Iron (Fe) 2.6 2.6 2.6 



Manganese (Mn) C) C) O 



Zinc (Zn) (■) C) O 



Calcium (Ca) C) O O 



Magnesium (Mg) C) C) C) 



Sulfate (SO.) O O O 



Chloride (CI) 1,000 200 200 



Dissolved solids 1,080 1,080 1,080 



Suspended solids C) C) C) 



Hardness (CaCOs) 475 475 475 



pH, units 4.6-9.4 4.6-9.4 4.6-9.4 



Color, units 360 360 360 



Temperature, F Q) (') 95 



1 Accepted as received (if meeting total solids or other limit- 

 ing values); has never been a problem at concentrations 



encountered. 



NOTE. — Application of the above values should be based on 

 Part 23, ASTM book of standards (1), or APHA Standard 

 methods for the examination of water and wastewater (5). 



Steam quality requirements are the same as those 

 given under the steam generation and cooling 

 water section. 



In general, clarification, sedimentation, or filtra- 

 tion, either singly or in combination, and some- 

 times followed by softening, are employed in treat- 

 ing water for the pulp and paper industry. 



TABLE V-10. Quality Requirements of Water at 



Point of Use by the Pulp and Paper Industry 



(SIC 26) 



[Unless otherwise indicated, units are mg/l and values that 



normally should not be exceeded. Quality of water prior to the 



addition of substances used for internal conditioning.] 



Chemical pulp and paper 



Characteristics 



Mechanical 

 pulping Unbleached Bleached 



Silica (SiO.) C) 50 50 



Aluminum (Al) C) C) O 



Iron (Fe) 0.3 1.0 0.1 



Manganese (Mn) 0.1 0.5 0.05 



Zinc (Zn) C) C) C) 



Calcium (Ca) C) 20 20 



Magnesium (Mg) C) 12 12 



Sulfate (SO.) C) C) C) 



Chloride (CI) 1,000 200 200 



Dissolved solids C) C) C) 



Suspended solids C) 10 ^^ 10 = 



Hardness (CaCOa) C) 100 100 



pH, units 6-10 6-10 6-10 



Color, units 30 30 10 



Temperature, F C) C) 95 



1 Accepted as received (if meeting total solids or other 

 limiting values): has never been a problem at concentrations 

 encountered. 



- No gritty or color-producing solids. 



NOTE. — Application of the above values should be based on 



Part 23, ASTM bool< of standards (1), or APHA Standard 

 methods for the examination of water and wastewater (5). 



MECHANICAL PULPING 



EVAPORATION 

 390 



950 



EVAPORATION 

 ,550 



240 



28,100 



f219Qi I 

 4040^11^^ ▲ I 



SCREENING ^i^ THICKENING aj^ DRYING ^ 



SCREENING 



2750 



240 



Figure V-2— Flow diagram showing water intake, recycling, and discharge in gallons per ton of 

 product for pulp and paper making- by a typically mechanical pulping mill. 



199 



