Use of fly ash to treat spent liquor from a thermomechanical pulping process
AssigneeLakehead University
InventorsPedram Fatehi, Farshad Oveissi
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Abstract
The spent liquor (SL) of a thermomechanical pulping (TMP) process introduces a high load to the wastewater system of this process. To reduce this load, fly ash from a biomass boiler is used for removing lignin from the SL, and also for decreasing the chemical oxidation demand (COD) and turbidity of the SL.
Claims16
A method of treating spent liquor from a pulping process of a pulp mill, the method comprising treating spent liquor from a steam pretreatment stage of a thermomechanical pulping process with fly ash obtained from a bark boiler, wherein said fly ash is applied to said spent liquor at a wastewater pretreatment stage upstream from a biological wastewater treatment stage to which the pretreated spent liquor is subsequently subjected.
Dependencies are inferred from the claim text.