Main Article Content
Pulp mill effluents have a complex composition of substances, with a high organic load
and recalcitrant compounds that hinder treatment in commonly applied biological
systems, such as activated sludge. Thus, it is necessary to carry out studies to improve
these procedures. Therefore, this work aimed to evaluate an activated sludge system
with the addition of powdered activated carbon (PAC) as support medium for
biomass to treat kraft effluent. The reactor was operated for 110 days in 4 stages.
The first stage corresponded to activated sludge only and the others were operated
with PAC addition of 2, 4, and 6 g L-1 (stages II, III, and IV, respectively). The removal
of organic matter was greater in the steps with medium support, obtaining averages
of 55, 94 and 58% for COD, BOD5, and TOC, respectively. Specific parameters such as
color, lignin derivatives and aromatic compounds were removed in, on average, 28,
29 and 36%, respectively in the stages with the PAC. Biofilm formation was observed
on the surface of the support medium during treatment, with a higher concentration
of biomass in step IV, reaching 4,086 mg L-1 of volatile suspended solids. Overall, the
addition of PAC as a support medium in the activated sludge system has improved
treatment efficiency. However, the increase in the concentration of PAC in the reactor
did not show significant improvements, which indicates the amount of 2 g L-1 of PAC
as the best concentration applied in the activated sludge system.
This work is licensed under a Creative Commons Attribution 4.0 International License.