Aiming at the pollution problem of methylene blue dye wastewater, a new type of methylene blue adsorbent magnesium-modified fly ash (Mg@FA) was prepared by using solid waste fly ash as raw material. The effects of Mg@FA dosage, adsorption time, and methylene blue concentration on the adsorption of methylene blue by Mg@FA and pH values were analyzed. The adsorption characteristics of Mg@FA on methylene blue were investigated by adsorption kinetics, adsorption isotherms, and adsorption thermodynamics, as well as SEM, EDS, XRD, BET, and FTIR. The results showed that when the dosage of Mg@FA was 1.0 g, the adsorption time was 120 min, and the initial concentration of methylene blue was 150 mg/L; the adsorption efficiency of methylene blue by Mg@FA was the highest, which was 95.61%. When the pH of the methylene blue solution was in the range of 7–11, the adsorption efficiency of Mg@FA for methylene blue remained stable at 95.61–98.10%. The adsorption process of methylene blue by Mg@FA follows the second-order kinetic fitting model and Langmuir model. The adsorption of methylene blue by Mg@FA is a spontaneous and endothermic reaction. Mg@FA adsorbs methylene blue through electrostatic interaction and hydrogen bonding. Mg@FA can effectively adsorb methylene blue and promote the waste utilization of fly ash, which provides a promising method for wastewater treatment and fly ash utilization.

The traditional preparation of ZSM-5 molecular sieves relies on chemical reagents to provide silicon and aluminum sources, which are limited as raw materials and cannot be commonly used in production practice. Using coal gangue as the raw material and using medium-temperature chlorination roasting and the pressure acid leaching process to control the silicon–aluminum ratio [n(Si/Al)] of coal gangue, a ZSM-5 molecular sieve was prepared using the alkali melting hydrothermal method. The pressure acid leaching process solved the limitation that kaolinite and mica cannot simultaneously be activated. Under optimal conditions, the n(Si/Al) of the coal gangue increased from 6.23 to 26.14 and complied with the requirements for the synthesis n(Si/Al) of a ZSM-5 molecular sieve. The effect of n(Si/Al) on the preparation of the ZSM-5 molecular sieve was studied. Finally, spherical granular ZSM-5 molecular sieve material with a microporous specific surface area of 169.6329 m²/g, an average pore diameter of 0.6285 nm, and a pore volume of 0.0988 cm³/g was prepared. Providing ideas for the high-value utilization of coal gangue, it is significant for solving the problem of coal gangue solid waste, as well as the problem of ZSM-5 molecular sieve feed stock.

The comprehensive utilization of low-grade diatomite resources and the effective treatment of printing and dyeing wastewater have attracted widespread attention. The combined scrubbing-magnetic separation-acid leaching-roasting process was used to increase the SiO₂ content from 59.22% to 86.93%, reduce the Al₂O₃ content from 18.32% to 6.75%, and reduce the Fe₂O₃ content from 6.85% to 1.24% in the low-grade diatomite from Heilongjiang, China. The TiO₂/g-C₃N₄/diatomite nanocomposite was prepared by a facile ultrasonic-thermal polymerization method. In this ternary structure, diatomite skeleton effectively increased the surface area with abundant adsorption sites, prevented g-C₃N₄ from restacking, and facilitated the separation of electrons and holes via the formation of TiO₂/g-C₃N₄ heterojunctions. The degradation rate was 98.77%, 90.59%, and 89.16% for the three catalytic reaction cycles of the MB solution, respectively. The composite showed a high degradation rate of the MB solution after three cycles, which indicated that the composite had good recyclability. Through the free radical capture test, it was elucidated that O₂⁻·, h⁺, and ·OH all played a role in the photocatalytic reaction of the TiO₂/g-C₃N₄/diatomite to the MB solution, in which O₂⁻· was mainly responsible for the photocatalytic oxidation mechanism, and the reaction kinetics were further investigated. This nanostructured TiO₂/g-C₃N₄/diatomite composite has fascinating visible light catalytic activity and excellent stability.

Rock can undergo shape deformation and damage due to the influence of joint fissures, and the range of damage caused by joints at different rock bridge angles varies. To study the influence of rock bridge angle on the size effect of rock secant modulus, this paper adopts the principle of regression analysis and combines numerical simulation to carry out relevant research. The research results indicate that: (1) As the rock bridge angle increases, the secant modulus gradually decreases, following a power function relationship. (2) As the rock size increases, the secant modulus shows a trend of first decreasing and then stabilizing, following a power function relationship. (3) As the rock bridge angle increases, the characteristic tangent modulus and characteristic size gradually decrease, following a power function relationship. On this basis, we obtained their relationship formulas separately.