dc.description.abstract
In recent years, due to climate change and increasing water scarcity, there has been a growing
need to promote new technologies for the reuse and regeneration of treated wastewater in
Wastewater Treatment Plants. However, the simultaneous presence of natural organic matter
(NOM) and persistent organic pollutants (POP) in reclaimed water presents a significant
challenge, as meeting high-quality standards requires treatments of varying intensity depending
on the intended final use.
This study evaluates the adsorption capacity of three commercial activated carbons (AC), Airpel,
A1100, and RB3, for the removal of both NOM and POP.
First, the surface chemical properties of the AC were characterized using two techniques: the point
of zero charge (pHpzc) and the Boehm titration method. After characterization, the adsorption
performance of the AC was assessed for the removal of NOM and POP, both independently and
simultaneously, to examine the existence of any competitive adsorption effects.
The experimental results were fitted to two kinetic models: First order and second order, to
calculate the rate constants and correlation coefficients, thereby identifying the best-fitting model
and the AC with the most favorable adsorption kinetics.
Surface characterization results indicated that A1100 exhibited an acidic surface, RB3 a basic
surface, and Airpel a neutral surface.
Regarding adsorption performance, Airpel showed the fastest kinetics for the independent
removal of NOM. Conversely, RB3 exhibited the highest adsorption rates for POP, with triclosan
and chlorpyrifos being the most efficiently removed compounds by all three AC, while atrazine
showed the lowest removal rates.
Lastly, a clear competitive effect between NOM and POP was observed, resulting in reduced
adsorption kinetics and efficiency for both types of compounds. This competitive effect was
particularly pronounced with RB3. These findings suggest that the selection of activated carbon
should be based on the specific contaminants present in the water and the desired treatment
objectives. In addition, further studies could help to better understand the long-term performance
of these materials under real operating conditions
