title: Catalytic hydrodechlorination of PCDD/Fs from condensed water with Pd/γ-Al2O3.
abstract: A continuous pyrolysis system (CPS) with effective air pollution control devices (APCDs) is designed and constructed to remediate the soil containing high-concentration PCDD/Fs. The quench tower of the APCDs system can capture the pollutants of high boiling points from the flue gas of CPS and produces condensed water of high PCDD/Fs concentration (16-44 ng I-TEQ/L), and needs further treatment. First, the result of activated carbon adsorption test displays the PCDD/Fs toxicity concentration of effluents meet the regulatory standards as the liquid to solid ratio is controlled at 3: 1. However, large amount of activated carbon need to achieve the high removal efficiency leads to high cost, so catalytic hydrodechlorination technology with Pd/Al2O3 as catalyst is applied to treat the condensed water. The PCDD/Fs mass removal efficiency achieved without the reducing agent is 53.21% with the operating time of 180 min. As 5% reducing agent (methanol) is added, the removal efficiency increases to 71.86%. In addition, to better understand the differences between molecular hydrogen and hydrogen donor, the condensed water was pre-aerated with hydrogen and catalytic hydrodechlorination test with palladium as catalyst was conducted. The results show that the PCDD/Fs mass removal efficiency increases to 97.34% with the operating time of 180 min, demonstrating the high PCDD/Fs removal efficiency of catalytic hydrodechlorination.
authors.affiliation: Graduate Institute of Environmental Engineering, National Central University, 300 Jhongda Rd., Jhongli District, Taoyuan City, 320, Taiwan, ROC.
authors.forename: Mei-Chen
authors.initials: MC
authors.lastname: Liu
authors.affiliation: Graduate Institute of Environmental Engineering, National Central University, 300 Jhongda Rd., Jhongli District, Taoyuan City, 320, Taiwan, ROC.
authors.forename: Shu-Hao
authors.initials: SH
authors.lastname: Chang
authors.affiliation: Graduate Institute of Environmental Engineering, National Central University, 300 Jhongda Rd., Jhongli District, Taoyuan City, 320, Taiwan, ROC. Electronic address: mbchang@ncuen.ncu.edu.tw.
authors.forename: Moo-Been
authors.initials: MB
authors.lastname: Chang
mesh_terms: D000327:Adsorption; D000393:Air Pollutants / Q000737:chemistry / Q000302:isolation & purification*; D000537:Aluminum Oxide / Q000737:chemistry*; D002384:Catalysis; D002606:Charcoal; D052918:Environmental Restoration and Remediation; D054879:Halogenation; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry / Q000302:isolation & purification*; D017745:Incineration / Q000379:methods; D007854:Lead / Q000737:chemistry*; D000072317:Polychlorinated Dibenzodioxins / Q000737:chemistry / Q000302:isolation & purification*; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D000393:Air Pollutants; D006843:Hydrocarbons, Chlorinated; D000072317:Polychlorinated Dibenzodioxins; D014874:Water Pollutants, Chemical; D002606:Charcoal; D007854:Lead; D000537:Aluminum Oxide
keywords: Hydrodechlorination; PCDD/Fs; Palladium catalyst