安全与环境学报

分别利用无机盐、无机酸和稀土对天然沸石进行了改性处理 ,并从理论上阐述了不同方法对沸石进行改性的机理 ,提出了改性沸石的最佳制备方法 ,并采用 X衍射的分析手段观察化学处理对载体的影响 ,探讨了改性沸石对 NH4 +吸附动力学以及再生实验。研究表明 ,3种方法均不同程度地提高了沸石去除氨氮的能力 ,其中利用无机盐改性的沸石的效果最佳 ,对 NH4 +的吸附动态符合 Freundlich方程 ,与传统的化学凝聚法和生物法相比 ,具有工艺简单、高效、经济等优点。无机盐改性沸石制备最佳条件是 :溶液中钠离子浓度为 0 .8mol/ L,在水浴温度 70～75℃时 ,按固液比 1∶ 50投加沸石 ,浸渍时间为 2 h,过滤后滤饼在 1 0 0℃下干燥 1 h。

The present paper aims to introduce the authors' new ways on how to activate the natural zeolite and treat inorganic acid, inorganic salt, rare earth and the similar inorganic elements. First of all, the authors of the paper have given an account of the principles of the various activating methods. Then, comparing the testing results of ammonia nitrogen removal efficiency (or adsorption capacity), the paper presents the optimal method and the effect on the carrier caused by the chemical treatment, should be examined by means of X-ray diffraction. And finally, the kinetics of NH₄~+ adsorption by activated zeolites and the refreshing experiments were investigated. The results of the present research show that all the above methods help to enhance the capacity of removing Ammonia-nitrogen from wastewater to a great extent. However, among these methods, the best one is the treatment with inorganic salt. The optimal process for manufacturing it should be based on the following conditions: the zeolite carrier should be soaked for 2 h in the 0.8 mol/L Na⁺ solution under 70~75 ℃. The total solid/liquor ratio is equal to 1∶50. Then, the carrier can be dried at 100 ℃ for 1h. In addition, it is also proved that the NH₄~+ adsorption process is well described by modified Freundlich. As compared with the chemical coagulation and biological method, the absorption method is simpler, more efficient and profitable. Hence, it can be used as a new approach to further treatment of urban sewage waste.