Influence of Modified Coal Fly Ash on Its Cation Exchange Capacities

摘要

Fly ash modified with sodium hydroxide calcination-hydrothermal was used to treat ammonia-nitrogen wastewater. The mount of alkali, the solid-liquid ratio, and the temperature of calcination were investigated in the process of modification. The best modified condition was when the ratio of sodium hydroxide and fly ash was 0.4:1, the ratio of solid and liquid was 1:1, and the temperature of calcination was 400℃. After modification, the zeolite-like substances were produced from the fly ash and the cation exchange capacities (CEC) increased from 5 to 81 mmol/100 g. The separation efficiency of the ammonia-nitrogen was up to 90%.