Abstract
In order to make full use of waste as raw materials to prepare low-cost zeolite, develop green chemical industry and achieve the purpose of treating waste with waste. High-purity zeolite X was prepared by the alkaline fusion hydrothermal method (AFH) using waste basalt powder as raw material, and was used as an adsorbent to investigate the adsorption performance for uranium-containing wastewater. The structure, morphology, specific surface area, chemical composition, chemical bonds, characteristic functional groups and chemical states of surface elements of the samples were characterized by XRD, SEM, BET, EDS, FT-IR and XPS. zeolite X with high crystallinity and rich hydroxyl/carboxyl groups was successfully synthesized by the AFH method, and its specific surface area was as high as 623.4 m2·g-1. When the adsorption time (t) is 720 min, the adsorption temperature (T) is 30 ℃, the initial uranium (VI) concentration is (C0) 35 mg/L, pH is 6.0, and the adsorbent dosage (m) is 5/35 mg/mL, the equilibriu adsorption capacity of zeolite X for uranyl ions is 228.4 mg·g-1. Thermodynamic results show that the adsorption process of uranyl ions by zeolite X is spontaneous and exothermic. Freundlich isotherms and quasi-second-order models are suitable to describe the adsorption process of uranyl ions by zeolite X. XPS analysis results show that -OH and -COOH play an important role in the adsorption process. At the same time, there is ion exchange between UO22+ and zeolite during the adsorption process.