Herein, based on existing standards for the measurements of material degradation rates and the degradation abilities of microorganisms, four methods were designed to determine material degradation rates. These four methods included two standard methods (inoculums: composting, vermiculite+composting leachate) and two experimental methods (inoculums: vermiculite+Bacillus, vermiculite+thermophilic bacteria). For this, the raw paper and plastic film (polylactic acid, PLA) components of environmentally friendly tape, as well as the finished tapes, were used as test materials to compare the material degradation rates using the above methods. Throughout the 60-day test cycle, both the PLA films and raw paper presented high degradation rates according to the four methods. The degradation rate of finished tape products increased gradually under the composting and vermiculite+composting leachate treatment and marginally rapidly under the vermiculite+Bacillus treatment. Additionally, under the vermiculite + thermophilic bacteria treatment method, the finished tape materials displayed a markedly higher degradation rate than that produced by other methods (roughly 1.7 ~ 7.5 times). Thus, the addition of microorganisms, particularly thermophilic bacteria, enhances the testing efficiency of material biodegradation rates. Therefore, we suggest that the optimization of degradation cultures can improve the testing efficiency of material degradation parameters, allowing manufacturing enterprises to shorten the research and development cycles of biodegradable products.
Aluminum (Al) used for hydrogen generation and aqueous contaminant removal has been widely studied given its abundance and low redox potential; the reduction ability of Al, moreover, is restricted by the passive surface oxide film on Al particles. In addition to common Al surface treatment methods, such as acid/alkali washing, alloying, and mechanical ball-milling, Al surface modification technology arising in recent years has also been confirmed as an efficient Al activation method given its economical cost and benign manufacturing process. In this study, the merits and disadvantages of surface modification relative to other Al surface treatment methods were highlighted by reviewing existing research on the application of Al surface modification in hydrogen generation and aqueous contaminant removal. In addition, the paper presents an outlook on Al surface modification technology used for hydrogen generation and aqueous contaminant removal to promote the study of related processes.
A I-TiO2/Sr2MgSi2O7:Eu,Dy composite photocatalyst was prepared via hydrolysis for efficient degradation of organic pollutants in the absence of light. In this paper, the photocatalytic degradation of Rhodamine B (RhB) by the composite photocatalyst was studied. The results show that the degradation ability of I-TiO2/Sr2MgSi2O7:Eu,Dy composite photocatalyst with a I-TiO2 ratio of 30% is better, and the degradation efficiency of RhB pollutants reached 31.9% in 6 h without a light source. These results indicate that a Sr2MgSi2O7:Eu,Dy composite photocatalyst, supported by long afterglow phosphor, can absorb light energy and become a new light source in light-free or low-light environments for the photocatalytic reaction of I-TiO2 in order to achieve 24-hour catalytic purification.
In order to improve the low specific surface area of g-C3N4, three-dimensional (3D) porous g-C3N4 was prepared using high temperature thermal polymerization. Fe2O3/g-C3N4 catalyst was prepared by compositing the g-C3N4 with Fe2O3 to improve its visible light response. The decolorization rate of the Fe2O3/g-C3N4 catalyst reached 100% in 30 minutes with a g-C3N4 content of 900 mg, Rhodamine B (RhB) concentration of 20 mg·L–1, and H2O2 content of 15 mmol. The Fe2O3/g-C3N4 catalyst also demonstrated good performance in degrading other organics; the degradation rates of Methyl orange (MO) and Tetracycline (TC) reached 80% and 90%, respectively, in 30 minutes. This photocatalytic mechanism was explored by active group capture experiments, and the results show that h+ and ·OH play an important role in the progress of photocatalysis.
The photoanode of I-doped TiO2 nanotube arrays (ITNA) prepared by anodization exhibited better degradation performance than TNA. The planar photocatalytic fuel cell (p-PFC) obtained by combining ITNA and Pt electrodes achieved a maximum decolorization rate of 93.1% when the concentration of methylene blue (MB) was 6 mg·L–1and the electrode plate spacing was 1.0 cm. The degradation of MB occurred on the surface of ITNA, which was a rate-limiting step. Compared to other structures, p-PFC had a higher photocatalytic performance and better production of h+ and ·OH, while degrading MB and other organics.