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In this work, for the first time, high-activity filtrates were prepared by the reaction of aluminum (Al) powder with hydrogen peroxide (H 2 O 2 ) in acidic solution and then filtration, which were used to degrade various organic pollutants such as phenol, methyl orange, and bisphenol A. It was found that the filtrates can effectively degrade and mineralize various organic pollutants and have a high efficiency comparable to their parent Al + acid + H 2 O 2 suspensions. The filtrates can keep their high activity for several weeks under ambient conditions, and the activity depends on their initial pH value. At a pH value of ∼3.5, the reaction activity of filtrates is the best. Electron spin resonance spectroscopy (ESR) analyses indicated that there is a large quantity of stable hydroxyl radicals (OH • ) existing in the filtrates, which are responsible for the removal of organic pollutants. Furthermore, the related factors are discussed.

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Nitrate is a contaminant widely found in surface water, and a high concentration of nitrate can pose a serious threat to human health. Zero-valent iron is widely used to reduce nitrate in aqueous solution, but an acidic condition is required. Zero-valent aluminum has a much lower redox potential (E 0(Al3+/Al0) = −1.662 V) than zero-valent iron (E 0(Fe2+/Fe0) = −0.44 V), making it a better choice for reduction of nitrate. However, a passive oxide film covering on Al surfaces inhibits its electron transfer. In this work, metal Al powder was activated by a soaking procedure in deionized water. It was found that nitrate in neutral solution can be efficiently and completely reduced by soaked Al, even if the concentration of nitrate-N was up to 100 mg L–1. Using an optimal soaking time, the soaked Al can remove >90% of nitrate in aqueous solution within ∼2 h at 50 °C. Furthermore, the nitrate reduction efficiency increased with increasing reaction temperature and dosage of Al powder. After reaction, only ∼50% of pristine N content was left in the form of ammonia ions (NH4 +) in aqueous solution. Mechanism analyses showed that after soaking, Al particle surfaces were covered by a layer of loose and fine Al­(OH)3 grains, which can shorten the induction time for the beginning of the reaction between inner Al and outside ions or molecules. This is the reason why soaked Al has a high efficiency for nitrate removal. The present results indicate that soaking is an effective way to activate Al to remove nitrate in water.

On the basis of simulation analysis, according to the process route from macro to micro, the effects of the contact stress on the raceway surface and the micro stress distribution of the inclusion on the raceway sub surface on the fatigue life of high-speed track bearings are simulated and analyzed. Firstly, by establishing the most common spherical inclusion as the simulated inclusion in this paper, the influence of subsurface stress in the case of inclusion is compared and analyzed, and the influence of the size, depth and type of inclusion on the stress is explored. Secondly, the influence of the change of fatigue life with size, depth and type is obtained from the fatigue life results calculated by the fatigue life calculation formula. The simulation results verify that the fatigue calculation model has a certain degree of accuracy, which provides a basis for the future research on the fatigue life of high-speed railway bearings.