Treating PCDD/Fs by combined catalysis and activated carbon adsorption

• High-level concentrations of PCDD/Fs are hard to destroy catalytically.
• A mixture of catalyst and activated carbon can enhance the destruction and removal efficiency.
• Such a mixture performs well, even at low temperature (180, 160 °C).
• The AC characteristics may influence upon the adsorption and degradation ability of this mixture.

V2O5–WO3/TiO2 catalysts are used to destroy dioxins present in the gas phase, yet both their removal efficiency (RE) and destruction efficiency (DE) decrease with rising initial concentration (IC). Therefore, activated carbons (AC-1: based on lignite; AC-2: based on coconut shell) were mixed with the catalyst to tackle these high IC gases. A gas phase dioxin-generating system was used to supply three different stable IC-values. When the highest IC is used (20.5 ng I-TEQ N m−3) without AC, at 200 °C, the RE and DE-value of PCDD/Fs reaches only 76% and 64%, respectively. At the same conditions, using a mix of catalyst and AC-2, these RE and DE-values rise to 90.1% and 82.0%, respectively. The mix catalyst/AC also shows better performance at low temperature (160 and 180 °C). The AC characteristics influence upon the adsorption and degradation abilities of the mixtures.