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Technique | Description | Applicability | |
---|---|---|---|
a | Modified cooking before bleaching | See Section 1.7.2.1 | Generally applicable |
b | Oxygen delignification before bleaching | ||
c | Closed brown stock screening and efficient brown stock washing | ||
d | Partial process water recycling in the bleach plant | Water recycling may be limited due to incrustation in bleaching | |
e | Effective spill monitoring and containment with a suitable recovery system | Generally applicable | |
f | Maintaining sufficient black liquor evaporation and recovery boiler capacity to cope with peak loads | Generally applicable | |
g | Stripping the contaminated (foul) condensates and reusing the condensates in the process |
See Table 1 and Table 2. These BAT-associated emission levels are not applicable to dissolving kraft pulp mills.
The reference waste water flow for kraft mills is set out in BAT 5.
BAT-associated emission levels for the direct waste water discharge to receiving waters from a bleached kraft pulp mill
a The BAT-AEL ranges refer to market pulp production and the pulp production part of integrated mills (emissions from papermaking are not included). | |
b A compact biological waste water treatment plant can result in slightly higher emission levels. | |
c The upper end of the range refers to mills using eucalyptus from regions with higher levels of phosphorus (e.g. Iberian eucalyptus). | |
d Applicable for mills using chlorine containing bleaching chemicals. | |
e For mills producing pulp with high strength, stiffness and high purity properties (e.g. for liquid packaging board and LWC), emissions level of AOX up to 0,25 kg/ADt may occur. | |
Parameter | Yearly averagekg/ADta |
---|---|
Chemical oxygen demand (COD) | 7 – 20 |
Total suspended solids (TSS) | 0,3 – 1,5 |
Total nitrogen | 0,05 – 0,25b |
Total phosphorus | 0,01 – 0,03b Eucalyptus: 0,02 – 0,11 kg/ADtc |
Adsorbable organically bound halogens (AOX)d e | 0 – 0,2 |
BAT-associated emission levels for the direct waste water discharge to receiving waters from an unbleached kraft pulp mill
a The BAT-AEL ranges refer to market pulp production and the pulp production part of integrated mills (emissions from papermaking are not included). | |
b A compact biological waste water treatment plant can result in slightly higher emission levels. | |
Parameter | Yearly averagekg/ADta |
---|---|
Chemical oxygen demand (COD) | 2,5 – 8 |
Total suspended solids (TSS) | 0,3 – 1,0 |
Total nitrogen | 0,1 – 0,2b |
Total phosphorus | 0,01 – 0,02b |
The BOD concentration in the treated effluents is expected to be low (around 25 mg/l as a 24-hour composite sample).