Adsorption of ammonia nitrogen in rare-earth wastewater by modified fly ash
改性粉煤灰吸附稀土废水中的氨氮

Acid-modified and alkali-modified treatment of fly ash by sulfate and sodium hydroxide was performed to investigate adsorption characteristics and the optimal adsorption conditions of ammonia nitrogen in rare-earth wastewater by fly ash. The experimental results showed that the adsorption ability of fly ash was improved obviously after alkali-modified treatment, and the adsorption isotherms conformed to Freundlich and Langmuir isotherm under experimental conditions of alkali-modified fly ash dosage of 2 g, adsorption duration of 2 h, pH of 7.0~8.0. The result showed that the ammonia nitrogen adsorption by alkali-modified fly ash was benign and endothermic process, and the theoretical saturated adsorption amount was 1.9066 mg/g.