Influence of memory effect caused by aged bag filters on the stack PCDD/F emissions

Area of Science:

• Environmental Science
• Chemical Engineering
• Pollution Control

Background:

• Polychlorinated dibenzodioxins and furans (PCDD/Fs) are persistent organic pollutants.
• Bag filters are commonly used for particulate matter removal in industrial emissions.

Purpose of the Study:

• To investigate the "memory effect" of PCDD/Fs in aged bag filters.
• To determine the influence of this memory effect on industrial emissions.

Main Methods:

• Analysis of PCDD/F characteristics in flue gases before and after bag filters.
• Study conducted on one municipal solid waste incinerator (MSWI) and two electric arc furnaces (EAFs).

Main Results:

• Aged bag filters showed a negative PCDD/F removal efficiency after prolonged operation.
• Gaseous phase PCDD/Fs were released from contaminated filters, increasing stack flue gas concentrations.
• Specific PCDD/F congeners were released differently by MSWI and EAF bag filters.

Conclusions:

• Bag filter "memory effect" is a significant factor in PCDD/F emissions.
• Understanding this effect is crucial for accurate pollution control and environmental monitoring.