Multi-structured Ag/MnO₂-cordierite molded catalysts were prepared by hydrothermal method and applied to the catalytic oxidation of VOCs. Catalytic activities of Ag/MnO₂-cordierite were evaluated by 1000 ppm of toluene, ethyl acetate and chlorobenzene degradation respectively at the air atmosphere, and their physicochemical properties were characterized through multiple techniques containing XRD, SEM, TEM, H₂-TPR and XPS. It is found that nanorod Ag/MnO₂-cordierite molded catalyst showed prominent catalytic activity for VOCs decomposition and the T₉₀ for toluene, ethyl acetate and chlorobenzene are 275 °C, 217 °C and 385 °C respectively under the space velocity of 10,000 h⁻¹. High valence manganese oxide, more active lattice oxygen proportion and superior low-temperature reducibility were the great contributors to the high activity of the catalyst with nanorod morphology. Studies of space velocity and catalytic stability over nanorod Ag/MnO₂-cordierite molded catalyst have confirmed the good catalytic performance, excellent mechanical strength and satisfied anti-toxicity to Cl at higher space velocity, which indicates that this molded catalyst have promise for industrial application.

Household dust is a sink for multiple toxic chemicals with known or suspected potential health effects. However, most dust exposure studies focus on a few chemicals, which may limit overall understanding of human exposure characteristics because people spend most of their time indoors. This paper describes the development and evaluation of a multi-residue analysis of 20 organochlorine pesticides (OCPs), 15 polycyclic aromatic hydrocarbons (PAHs), 8 polybrominated diphenyl ether congeners (PBDEs), 3 hexabromocyclododecane (HBCDs), 8 synthetic musks (Musks), and 7 organophosphate esters (OPEs) in indoor dusts. After extraction with acetone/hexane (v/v, 1 : 1), all target compounds were fractionated with a Florisil solid-phase extraction (SPE) cartridge into two fractions: PAHs, PBDEs, HBCDs, OCPs and Musks, which were eluted with hexane/dichloromethane, and OPEs eluted with ethyl acetate. Further clean-up using acidified silica 44% cartridges was then performed to enable determination of PBDEs and HBCDs. Instrumental analysis of the target chemicals was performed using gas chromatography (GC) or liquid chromatography (LC) coupled with mass spectrometry (MS) or tandem mass spectrometry (MS/MS). A newly-optimized GC-MS/MS method was employed for the simultaneous determination of PAHs, OCPs, and Musks. The lower limit of quantification (LOQ) values of PAHs, OCPs, and Musks were 0.14–0.92 ng g⁻¹, 0.06–0.38 ng g⁻¹ and 0.07–0.40 ng g⁻¹, respectively. PBDEs were quantified by GC-MS with electron capture negative ionization, and HBCDs and OPEs by LC-MS/MS with electrospray ionization (ESI) in negative and positive ion mode, respectively. Recovery experiments showed that the average recoveries and relative standard deviations were 99–113% and 1–14% for PBDEs, 89–105% and 1–6% for HBCDs, 71–120% and 3–17% for PAHs, 71–112% and 2–17% for OCPs, 77–120% and 2–13% for Musks, and 80–127% and 1–14% for OPEs. Validation experiments showed that the method achieved good accuracy. The developed method was used to analyze SRM 2585 and real indoor dust samples to demonstrate its suitability for routine analysis. The target contaminants were widely detected in SRM 2585 and indoor dust collected from Wuhan of Central China, with PAHs the major species, followed by OPEs, OCPs, and PBDEs.

Layered δ-MnO₂ catalysts were prepared using the one-step redox method in precursor solutions with five different pH values (pH = 7, 9, 11, 13, and 14). The effects of pH on the physical properties and catalytic activity of the catalyst were investigated through XRD, SEM, TEM, BET, XPS, H₂-TPR, and HCHO degradation tests at room temperature. The results showed that the layer spacing, manganese vacancy content, Mn⁴⁺/Mn³⁺ ratio, and surface-reactive oxygen species content of MnO₂ increased with the increase in pH value in the alkaline range. When the catalyst was prepared at pH = 13, the above characteristics of the catalyst reached the optimal value which contributed to the high catalytic activity. Combined with the related characterization results, it was proved that changing the pH can affect the degree of oxidation in the catalyst synthesis process, increase the number of active oxygen and the oxygen mobility of the catalyst, and effectively improve the catalytic activity of the manganese dioxide catalyst for HCHO. This work represents a giant step toward the preparation of an effective catalyst for practical applications of HCHO removal at room temperature at a low concentration and high velocity.

TiO2-ZSM-5/ceramic fiber composite was successfully prepared for the first time by impregnation and applied to remove toluene in the atmosphere and RhB in wastewater. Optional values for TiO2 loading and calcination temperature were discussed. The composites were characterized by XRD, SEM, TEM, UV-vis and N2 adsorption-desorption. The results showed that TiO2 loading amount affects the crystal formation, distribution, pore size and adsorption capacity for pollutants, which in turn determines the adsorption performance and photocatalytic activity of the composite. Composites calcined at 550 ℃ with 12.7 wt. % TiO2 loading can degrade toluene and RhB most effectively, with the maximum degradation rates of 39.99% and 92.70%, respectively. In addition, materials have been proven to have high degradation stability being recycled 4 times. The TiO2-ZSM-5/ceramic fiber prepared in this study can degrade atmospheric and industrial wastewater pollutants. Therefore, TiO2-ZSM-5/ceramic fiber has high comprehensive practical value in the field of environmental pollutant removal.