用煤矸石合成4A沸石分子筛处理氨氮废水

以煤矸石为原料，采用碱熔-水热法合成4A沸石分子筛。由于煤矸石中铝、硅主要以高岭土形式存在，其活化过程是合成4A沸石分子筛关键环节。为提高4A沸石分子筛钙离子的交换能力，增加对模拟废水氨氮的去除率，实验考察了碳酸钠与煤矸石质量比、活化温度、活化时间、晶化温度和晶化时间对4A沸石分子筛钙离子交换能力的影响，同时也考察了模拟废水的pH、4A沸石分子筛加入量及吸附时间对氨氮去除率的影响。结果表明，最佳工艺条件为，碳酸钠与煤矸石质量比为0.9、活化温度为800℃、活化时间1.5 h、晶化温度90℃和晶化时间3 h。合成4A沸石分子筛的钙离子交换能力为310 mg/g，在pH为6的100 mL模拟氨氮废水中加入6 g 4A沸石分子筛吸附40 min后，废水中氨氮的去除率达到86%。通过最佳工艺条件合成4A沸石分子筛，在处理氨氮废水方面具有一定的应用前景。

Removal of ammonia-nitrogen in wastewater with 4A zeolite molecular sieve synthesized from coal gangue

4A zeolite molecular sieve is synthesized from coal gangue by alkaline-hydrothermal method,which can help to save natural resource and alleviate environmental pressure.Kaolin is the main existing form of alumina and silicon in coal gangue.Activation of coal gangue is the key unit in synthesis of 4A zeolite molecular sieve.The influences of several important parameters on exchange ability of calcium ions and ammonia-nitrogen removal,such as the mass ratio of sodium carbonate to coal gangue,activation temperature,activation time,crystallization temperature,crystallization time,pH value,4A zeolite molecular sieve dose and adsorption time,were studied.The experiment results indicated that under the conditions of the mass ratio of sodium carbonate to coal gangue of 0.9,the activation temperature of 800℃, the activation time of 1.5 h,the crystallization temperature of 90℃,and the crystallization time of 3 h,the exchange ability of calcium ions was 310 mg/g.The ammonia-nitrogen removal rate of 86% was obtained as follows: the wastewater pH value of 6,the 4A molecular sieve dosage of 6 g to 100 ml wastewater,the adsorption time of 40 min.4A zeolite molecular sieve show an application prospect for treating ammonia-nitrogen wastewater.