Biohydrogen production from synthetic waste, SW (model organic fraction of municipal solid waste) co-digested with liquid dairy manure (M) was tested in batch reactions to assess the effect of temperature and mixi...Biohydrogen production from synthetic waste, SW (model organic fraction of municipal solid waste) co-digested with liquid dairy manure (M) was tested in batch reactions to assess the effect of temperature and mixing ratio of the substrates. A 5 × 2 factorial design experiment was conducted. Synthetic waste: manure mixtures of 1:1, 2:1, 3:1, 1:0, 0:1 (volatile solids, VS, basis) were tested at 37 (T37) and 55 ℃ (T55) using thirty 1 L laboratory scale digesters. Total VS of each mixture was 50 g/L except SW:M 0:I treatment, where total VS was 27.4 g/L. Gas samples were taken daily to determine hydrogen production, and slurry samples taken before and after experimentation, were analyzed for volatile fatty acid (VFA) concentration, volatile solid (VS) degradation, ammonium nitrogen (NH4+-N) and pH. Hydrogen production (mL/g-VS fed) showed a significant two-factor interaction between incubation temperature and SW:M ratio (P 〈 0.001). Maximum production of 15.8 mL/g-VS (fed) was achieved in SW:M ratio of 3:1 at 55 ℃. Generally, hydrogen productions at thermophilic temperature (T55) were significantly higher than at mesophilic (T37) temperature for all treatments (P 〈 0.001) except for SW:M 1:0 and SW:M 0:1 treatments (P 〉 0.05). This study indicates that hydrogen production from co-digestion of synthetic waste and manure is dependent on incubation temperature and relative contribution of wastes in the mixture.展开更多
Multifunctional devices are of great interest for integration and miniaturization on the same platform, but simple addition of functionalities would lead to excessively large devices. Here, the photodetection and chem...Multifunctional devices are of great interest for integration and miniaturization on the same platform, but simple addition of functionalities would lead to excessively large devices. Here, the photodetection and chemical sensing device is developed based on two-dimensional(2D) glassygraphene that meets similar property requirements for the two functionalities. An appropriate bandgap arising from the distorted lattice structure enables glassy graphene to exhibit comparable or even improved photodetection and chemical sensing capability, compared with pristine graphene. Due to strong interactions between glassy graphene and the ambient atmosphere, the devices are less sensitive to photoinduced desorption than the ones based on graphene. Consequently,the few-layer glassy graphene device delivers positive photoresponse, with a responsivity of 0.22 A W^(-1) and specific detectivity reaching ~10^(10) Jones under 405 nm illumination.Moreover, the intrinsic defects and strain in glassy graphene can enhance the adsorption of analytes, leading to high chemical sensing performance. Specifically, the extracted signalto-noise-ratio of the glassy graphene device for detecting acetone is 48, representing more than 50% improvement over the device based on graphene. Additionally, bias-voltage-and thickness-dependent volatile organic compound(VOC) sensing features are identified, indicating the few-layer glassy graphene is more sensitive. This study successfully demonstrates the potential of glassy graphene for integrated photodetection and chemical sensing, providing a promising solution for multifunctional applications further beyond.展开更多
文摘Biohydrogen production from synthetic waste, SW (model organic fraction of municipal solid waste) co-digested with liquid dairy manure (M) was tested in batch reactions to assess the effect of temperature and mixing ratio of the substrates. A 5 × 2 factorial design experiment was conducted. Synthetic waste: manure mixtures of 1:1, 2:1, 3:1, 1:0, 0:1 (volatile solids, VS, basis) were tested at 37 (T37) and 55 ℃ (T55) using thirty 1 L laboratory scale digesters. Total VS of each mixture was 50 g/L except SW:M 0:I treatment, where total VS was 27.4 g/L. Gas samples were taken daily to determine hydrogen production, and slurry samples taken before and after experimentation, were analyzed for volatile fatty acid (VFA) concentration, volatile solid (VS) degradation, ammonium nitrogen (NH4+-N) and pH. Hydrogen production (mL/g-VS fed) showed a significant two-factor interaction between incubation temperature and SW:M ratio (P 〈 0.001). Maximum production of 15.8 mL/g-VS (fed) was achieved in SW:M ratio of 3:1 at 55 ℃. Generally, hydrogen productions at thermophilic temperature (T55) were significantly higher than at mesophilic (T37) temperature for all treatments (P 〈 0.001) except for SW:M 1:0 and SW:M 0:1 treatments (P 〉 0.05). This study indicates that hydrogen production from co-digestion of synthetic waste and manure is dependent on incubation temperature and relative contribution of wastes in the mixture.
基金supported by the National Natural Science Foundation of China (61974014)the EPSRC Future Compound Semiconductor Manufacturing Hub (EP/P006973/1)。
文摘Multifunctional devices are of great interest for integration and miniaturization on the same platform, but simple addition of functionalities would lead to excessively large devices. Here, the photodetection and chemical sensing device is developed based on two-dimensional(2D) glassygraphene that meets similar property requirements for the two functionalities. An appropriate bandgap arising from the distorted lattice structure enables glassy graphene to exhibit comparable or even improved photodetection and chemical sensing capability, compared with pristine graphene. Due to strong interactions between glassy graphene and the ambient atmosphere, the devices are less sensitive to photoinduced desorption than the ones based on graphene. Consequently,the few-layer glassy graphene device delivers positive photoresponse, with a responsivity of 0.22 A W^(-1) and specific detectivity reaching ~10^(10) Jones under 405 nm illumination.Moreover, the intrinsic defects and strain in glassy graphene can enhance the adsorption of analytes, leading to high chemical sensing performance. Specifically, the extracted signalto-noise-ratio of the glassy graphene device for detecting acetone is 48, representing more than 50% improvement over the device based on graphene. Additionally, bias-voltage-and thickness-dependent volatile organic compound(VOC) sensing features are identified, indicating the few-layer glassy graphene is more sensitive. This study successfully demonstrates the potential of glassy graphene for integrated photodetection and chemical sensing, providing a promising solution for multifunctional applications further beyond.