Green Synthesis Method and Application of NaP Zeolite Prepared by Coal Gasification Coarse Slag from Ningdong, China

Abstract

In view of the current and urgent environmental protection needs, the use of industrial solid waste in China’s Ningdong is becoming more and more important. In this paper, NaP zeolite with good physical properties is synthesized by using coal gasification coarse slag (CGCS) as the raw material, without the addition of a silicon and aluminum source, without the addition of a template agent, and without high-temperature calcination. Add a small amount of NaOH and deionized water to the CGCS to adjust the molar ratio to SiO2:Al2O3:Na2O:H2O = 5.2:1.0:5.0:100. The effects of aging time, crystallization temperature, and crystallization time parameters on synthetic zeolite were studied. The raw materials and the obtained zeolite were tested by XRF, XRD, SEM, FT-IR, TG-DSC, BET, and other technologies. The results show that the specific surface area of the synthesized NaP zeolite can reach 161.06 m2/g, which has the characteristics of large specific surface area, regular morphology, and high crystallinity. We obtained NaP zeolite through a simple and low-cost synthesis method. The synthesized NaP zeolite was used to simulate the removal of ammonia nitrogen in wastewater, and the optimal removal rate was 92.67%. Among them, Na+ plays an important role in the synthesis of NaP zeolite and ion exchange with NH4+. Our research provides new ideas for solving the large-scale accumulation of CGCS and treating ammonia nitrogen in industrial wastewater. Thus, it is a promising green environmental protection and “treating waste by waste” route.