Using a state-of-the-art air pollution control system to lower pollutant emissions

This study focused on the pollutant characteristics of a renovated laboratory waste treatment plant that adopted a state-ofthe-art design for its air pollution control system. The output materials, including slag, primary quenching tower ash, scrubbing wastewater, sludge, fabric filter ash, and flue gas, were sampled and analyzed. Incorporating an organic liquid waste injector into the primary combustion chamber enabled the local temperature to be increased to approximately 1300– 1400°C, thereby reducing the PCDD/F concentration in the slag to 0.019 ng I-TEQ g^–1 and the PCDD/F emission factor to 699 µg I-TEQ ton-waste^–1. In addition, the concentration of the flue gas was much lower than the regulated standard, and the low level of emissions contributed to the performance of the air pollution control devices. The fly ash contained crystalline-phase NaCl or other sodium salts that resulted from the neutralization of NaOH by acidic pollutants. However, high concentrations of Cl and PCDD/Fs were measured in the scrubbing wastewater and sludge, respectively. The scrubbing unit of the renovated air pollution control system was placed in front of the fabric filter to remove HCl, thus providing excellent protection for the filter.