Synthesis Of New Kaolin Molecular Sieves And Its Adsorption Of Ammonia

With the great development of economy, vast quantities of ammonia wastewaters are typical examples of uncontrolled utilization of industry wastewater and city life sewerage resources. Ammonia nitrogen contributes to accelerated eutrophication of lakes and rivers, dissolved oxygen depletion and life toxicity in receiving water. So, how to explore the effective treatment method of high ammonia nitrogen is urgent. Ion exchange has been widely investigated in ammonia removal. While, zeolite as the presentative of ion exchanger, has some difficults such as small adorption capacity, the instability of adsorption effects, fitting with the low concentration ammonia removal and so on. Therefore, the widely application in industry has been limited.According to the above reasons, synthesis of a new kaolin molecular sieves with high selectivity of ammonia and easy recovery performance was the goal of this paper. This research study on different preparation methods of the new kaolin molecular sieves. In order to improve the ability of ammonia removal, multivariate synergy on ammonia removal effect was studied during the process of making new kaolin molecular sieves. Moreover, The optimum conditions for the technology of this new kaolin molecular sieves was also investigated in this paper.And the principal conclusions were obtained as follows.(1) Through the column and batch study, we discoveryed Nanochem was a kind of synthetic ion exchange media, which has a significant ammonia removal ability. And its adsorption efficiency was 50-400 times higher than natural zeolite. As an imported products the price of Nanochem was expensive, while this kind of molecular sieves was very few.(2)In order to make a new kaolin molecular sieves we chosed kaolin as a raw material, and activated the kaolin through make the external environment hydrothermal and alkaline. The study showed that pH, activated time and temperature, the ratio of alkali and kaolin play an important role in the process of kaolin activation. High temperature can promote this process,and also with microwave calcination. It was discoveryed that the new kaolin molecular sieves remove ammonia rely on the ion exchange of K+mainly through XRD.(3)The disposal of the real high ammonia wastewater showed that flow rate has little effect on the ammonia removal, and the ammonia removal happened in a short time. The simulation by Langmuir and Freundlich model showed that the new kaolin molecular sieves remove ammonia in different kinds of real wastewater rely on the ion exchange mainly, meanwhile with physical adsorption.