Emission characteristics of dl-PCNs, PCDD/Fs, and dl-PCBs from secondary copper metallurgical plants: Control technology and policy. (August 2020)

• Record Type: Journal Article
• Authors: Dat, Nguyen Duy; Huang, Yong Ji; Hsu, Yen Chen; Chang, Moo Been
• Is Part Of: Chemosphere. Volume 253(2020)
• Publication Date: 2020-08
• Subjects: Emission factor -- Removal efficiency -- Emission standard -- Control policy; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2020.126651
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: This study investigated the characteristics of dl-PCNs, PCDD/Fs and dl-PCBs emitted from two typical secondary copper metallurgical plants processing copper sludge equipped with different sets of air pollution control devices (APCDs). Results indicated that the emission factors of dl-PCNs and PCDD/Fs of plant A are 0.00775 and 1.09 μg TEQ/ton, respectively, which are remarkably lower than those of plant B (3.12, 181 and 25.5 μg TEQ/ton for dl-PCNs, PCDD/Fs and dl-PCBs, respectively). Dl-PCNs contributed 0.7–2.7% of total TEQ for flue gases and up to 2.6% of TEQ for ash samples. The TEQ concentration of dl-PCNs in fly ash individually exceeds the regulated level of 1 ng TEQ/g regulated by Taiwan EPA, indicating that emission and discharge of dl-PCNs should be regulated. The combination of semidry scrubber and activated carbon injection (ACI) + baghouse (BH) is effective for simultaneous removals of dl-PCNs and PCDD/Fs in plant A; while the combination of cyclone, secondary combustion chamber, ACI + BH and wet scrubber (WS) is not optimal for removing dl-PCNs, PCDD/Fs and dl-PCBs. Memory effect occurring within BH and WS is responsible for low removal efficiencies of these POPs in plant B. This study suggests appropriate APCDs for simultaneous removal of three POP groups and recommends the inclusion of dl-PCNs in emission standard. Highlights: Characteristics of three POP groups emitted from two plants are investigated. Appropriate APCDs for simultaneous removals of POPs are suggested. Similar trends of removal and increase of POPs within APCDs are found.