改性天然片沸石去除氨氮的研究

Study on Modified Heulandite to Remove Ammonia Nitrogen

采用NaCl和KCl对天然片沸石进行改性,研究了改性片沸石的全交换容量,pH值、氨氮浓度和温度对改性片沸石离子交换性能的影响。结果表明:改性后钠型片沸石的全交换容量提高,而钾型片沸石的全交换容量有所降低;pH值为6.0时改性片沸石具有最大离子交换容量;较高氨氮浓度离子交换速率较快,相同氨氮浓度下钾型片沸石交换速率最快,而片沸石原矿样品的交换速率最低;低温有利于片沸石对NH4+交换反应进行;改性片沸石多次再生后交换容量均有所降低。

Sodium chloride and potassium chloride were adopted to modify the natural heulandite. Full ion exchange capacity of modified heulandite and the effects of pH, temperature and concentration of ammonia nitrogen on ion exchange capability of modified heulandite were studied. Results indicated that modification by sodium chloride improved the full ion exchange capability of heulandite, but modification by potassium chloride reduced the full ion exchange capability of heulandite. Modified heulandite had the biggest ion exchange capability at pH 6.0. There was a positive correlation between concentration of ammonia nitrogen and the ion exchange velocity. Heulandite modified by sodium chloride had the fastest ion exchange velocity and natural heulandite had the slowest ion exchange velocity at the same concentration of ammonia nitrogen. Low temperature promoted ion exchange reaction between heulandite and NH4^＋. The exchange capabilities of modified heulandite were reduced after many times of regeneration.