Co-pyrolysis of fly ash with sewage sludge for PCDD/F removal.

Fly ash generated from municipal waste incineration (MWI) contains various toxic substances, and it has to be properly treated before disposal or reuse. Water washing and thermal pyrolysis can improve the destruction efficiency of PCDD/Fs in fly ash generated from municipal solid waste incinerators. Since sulfur oxides and nitrogen compounds generated by the heating of the sewage sludge poison the catalytic active sites for PCDD/Fs formation on fly ash surface, co-pyrolysis of fly ash with sewage sludge effectively inhibits precursor formation and de novo synthesis reaction, resulting in the great reduction of PCDD/F formation.

Ozone catalytic oxidation of toluene over triple perovskite-type catalysts modified with KMnO.

A unique triple perovskite-type catalyst was successfully synthesized using the simple sol-gel approach, and surface acid modification was added to improve the ozone catalytic oxidation (OZCO) process ability to remove toluene more effectively. Our study indicates that LaMnCuNiO catalyst treated with KMnO shows the best toluene oxidation activity. At 250 °C, the rates of conversion and mineralization were 100% and 83%, respectively, under thermal catalytic system when CH concentration = 500 ppm.

Ozone catalytic oxidation of low-concentration formaldehyde over ternary Mn-Ce-Ni oxide catalysts modified with FeO.

Manganese oxide-based catalysts have attracted extensive attention due to their relatively low cost and remarkable performance for removing VOCs. In this research, we used the Pechini method to synthesize manganese-cerium-nickel ternary oxide catalysts (MCN) and evaluated the effectiveness of catalytic destruction of formaldehyde (HCHO) and ozone at room temperature. FeO prepared by the impregnation method was applied to modify the catalyst.

Characterization of PCDD/Fs and dl-PCBs emission from combustion of PCB-containing oil in a fluidized-bed incinerator.

Emissions of PCDD/Fs and dl-PCBs from the combustion of PCB-containing oil in a hazardous waste incinerator are characterized. Flue gas samples are simultaneously taken at three points, including the outlet of ultrasonic wet scrubber, the outlet of heat exchanger and stack. In addition, solid matter samples including incinerator bottom ash, wet scrubber sludge, heat exchanger ash and baghouse ash are also collected.

Characterization of polybrominated diphenyl ethers (PBDEs) in various aqueous samples in Taiwan.

In this study, 20 groundwater samples and 7 surface water samples were collected and analyzed by HRGC-HRMS to evaluate the levels, congener distributions, and dissolved/solid partitioning of polybrominated diphenyl ethers (PBDEs) in water matrix as well as the removal efficiency of a typical water treatment plant (WTP). The results indicated that the level of PBDEs concentrations ranging from 18.51 to 4212 pg/L and 30.

Atmospheric concentrations and gas-particle partitioning of PCDD/Fs and dioxin-like PCBs around Hochiminh city.

Atmospheric PCDD/Fs and dl-PCBs samples were collected in Hochiminh city, Vietnam to address the effect of meteorological parameters, especially rainfall, on the occurrence and gas/particle partitioning of these persistent organic pollutants. The results indicate that PCDD/Fs and dl-PCBs concentrations in industrial site are higher than those measured in commercial and rural sites during both rainy and dry seasons. In terms of mass concentration, ambient PCDD/F levels measured in dry season are significantly higher than those measured in rainy season while dl-PCB levels do not vary significantly between rainy and dry seasons.