First have to ask what kind ...
Published by Mark Milne, Wastewater Superintendent
First have to ask what kind of pulp mill, paper, dissolving sulfide...What processes are in the mill are there evaporators for red liquor, then you will have acid condensate. Is it a caustic extraction process, then you will have Black liquor which can be toxic if concentration is too high but can be diluted with acid condensate.
Both mills I worked added ammonia and phosphoric acid. One used aerobic for most streams and anaerobic processes, anaerobic for the black liquor. The other had a very large aeration basin. Solids were processed through screw presses and burnt in the power boilers.
I would map out all the waste streams, determine what treatment is fits and see which streams can be combined. Most mills have systems to recover and recycle from waste streams to reduce wastewater.
1 Comment
Thank you Mark for your answer. Actually this paper mill uses wastepaper as raw materials (not wood), so I suppose the Black liquor is not present? Yes I also think separating the streams for individual treatment is more proper. But for the mill in my case study, they mix all of wastewater fractions into only one stream.
Published by Hung Bui, Graduate Student. 1-year experience in water and wastewater sectors.