● An urchin-like OMS/ZIS composite was fabricated by a facile solvothermal method. ● The OMS/ZIS exhibits superior photocatalytic H2 evolution for organics degradation. ● A probable mechanism of dual-functional photocatalysis was proposed in detail. ● This work provides an inspiration for rational design of dual-functional catalysts. Achieving hydrogen production and simultaneous decomposition of organic pollutants through dual-functional photocatalytic reactions has received increasing attention due to the environmentally friendly and cost-effective characteristics of this approach. In this work, an urchin-like oxygen-doped MoS2/ZnIn2S4 (OMS/ZIS) composite was fabricated for the first time using a simple solvothermal method. The unique microstructure with abundant active sites and fast charge transfer channels further shortened the charge migration distance and compressed carrier recombination. The obtained composite exhibited an efficient H2 evolution reaction rate of 12.8 mmol/g/h under visible light, which was nearly times higher than pristine ZnIn2S4, and the apparent quantum efficiency was 14.9% (420 nm). The results of the simultaneous photocatalytic H2 evolution and organic pollutant decomposition test were satisfactory, resulting in decomposition efficiencies of resorcinol, tetracycline, and bisphenol A that reached 41.5%, 63.5%, and 53.0% after 4 h, respectively, and the highest H2 evolution rate was 672.7 μmol/g/h for bisphenol A. Furthermore, natural organic matter (NOM) abundantly found in actual water was adopted as an electron donor for H production under simulated sunlight irradiation, indicating the promising practicability of simultaneous hydrogen evolution and NOM decomposition. Moreover, the mechanisms of the dual-purpose photocatalytic reactions, as well as the synergistic effect between the molecular structures of the organic pollutants and the corresponding adsorption behavior on the photocatalyst surface were illustrated in detail. These obtained results may serve as an inspiration for the rational design of highly efficient, dual-functional photocatalysts in the future. 相似文献
Trimethylolpropane (TMP) wastewater is one of the most toxic petrochemical wastewater. Toxicants with high concentrations in TMP wastewater often inhibit the activity of microorganisms associated with biological treatment processes. The hydrolysis acidification process (HAP) is widely used to pretreat petrochemical wastewater. However, the effects of HAP on the reduction of wastewater toxicity and the relevant underlying mechanisms have rarely been reported. In this study, an HAP reactor was operated for 240 days, fed with actual TMP wastewater diluted by tap water in varying ratios. The toxicity of TMP wastewater was assessed with the inhibition ratio of oxygen uptake rate. When the organic loading rates were lower than 7.5 kg COD/m3/d, the toxicity of TMP wastewater was completely eliminated. When the actual TMP wastewater was directly fed into the reactor, the toxicity of TMP wastewater decreased from 100% to 34.9%. According to the results of gas chromatographymass spectrometry analysis, four main toxicants contained in TMP wastewater, namely, formaldehyde, 2-ethylacrolein, TMP and 2-ethylhexanol, were all significantly removed, with removal efficiencies of 93.42%, 95.42%, 72.85% and 98.94%, respectively. Compared with the removal efficiency of CODCr, the reduction rate of toxicity is markedly higher by HAP. In addition, the change of microbial community in the HAP reactor, along the operation period, was studied. The results revealed that, compared with the seed sludge, Firmicutes became the dominant phylum (abundance increased from 0.51% to 57.08%), followed by Proteobacteria and Bacteroidetes (abundance increased from 59.75% to 25.99% and from 4.70% to 8.39%, respectively).
• Urban aerosols harbour diverse bacterial communities in Shanghai.• The functional groups were associated with nitrogen, carbon, and sulfur cycling.• Temperature, SO2, and wind speed were key drivers for the bacterial community. Airborne bacteria play key roles in terrestrial and marine ecosystems and human health, yet our understanding of bacterial communities and their response to the environmental variables lags significantly behind that of other components of PM2.5. Here, atmospheric fine particles obtained from urban and suburb Shanghai were analyzed by using the qPCR and Illumina Miseq sequencing. The bacteria with an average concentration of 2.12 × 103 cells/m3, were dominated by Sphingomonas, Curvibacter, Acinetobacter, Bradyrhizobium, Methylobacterium, Halomonas, Aliihoeflea, and Phyllobacterium, which were related to the nitrogen, carbon, sulfur cycling and human health risk. Our results provide a global survey of bacterial community across urban, suburb, and high-altitude sites. In Shanghai (China), urban PM2.5 harbour more diverse and dynamic bacterial populations than that in the suburb. The structural equation model explained about 27%, 41%, and 20%–78% of the variance found in bacteria diversity, concentration, and discrepant genera among urban and suburb sites. This work furthered the knowledge of diverse bacteria in a coastal Megacity in the Yangtze river delta and emphasized the potential impact of environmental variables on bacterial community structure. 相似文献