Study On Treatment Of High Concentration Ammania-Nitrogen Wastewater With Zeolite Synthesized With Fly Ash

Fly ash is a kind of solid waste, which mostly comes from the coal-firing power plant. Because of the lack of the effectual utilization on fly ash, not only the fields, the rivers and the atmosphere were polluted, the environment was destroyed but also the human health was hurt.At present, fly ash utilization methods include extracting alumina or magnetite, fly ash bricks and fly ash concrete, but these are all low-level and low-value. On the contrary, the synthesis of zeolite from fly ash, which can increase its additive value, is receiving increasing attention.The fluent-bed coal fly ash was amorphous material and made up of quartz crystalline phase, without mullite crystalline phase. It has very high chemistry active and it is easy to translate fly ash into zeolite in some specific condition. The paper has studied synthesizing zeolite by using the selected high active fly ash and lye through obturating hydrothermal method and synthesized zeolite successfully.Firstly, the paper has studied using synthesizing zeolite to treat high concentration ammonia-nitrogen wastewater. When the concentration of NH₄⁺ in wastewater is 400mg/L, enter 3g zeolite into 50ml wastewater, adsorb 20 min, removing rate is upwards of 65%. The removing rate is not changed with time after this; when time is fixed, removing rate is increased with the increasing quantity of added zeolite.In order to utilize fly ash better, this paper has researched the regeneration of fly ash zeolite which was adsorbed with ammonia-nitrogen. The result shows that synthesizing zeolite can be regenerated not only by chemical methods but also by biological methods. The regeneration rate can be upwards of 60% whether using chemical methods or biological methods, and the highest regeneration rate can reach 80.4%. After being regenerated, the fly ash zeolite can use repeatedly. Compared with the first regeneration rate, the second regeneration rate decreased, but the down-range of the rate was not significant.In the regeneration process by chemical methods, the effect was influenced by the following factor: regenerated reagent, pH of the solution, regenerated time, etc. The mixed solution of NaOH and NaCl has the best effect in the selected condition. When the other factors are fixed, regeneration rate is decreased with the decreasing pH of regenerated solution.Different regeneration methods, different impacts. In the regeneration process by biological methods, the impact of using PSB is better than the impact of using nitrifying bacteria. PSB has the better advantage on agriculture utilization.There is a broad prospect in wastewater treatment field by zeolite synthesized with fly ash. Correspondingly, it is a new technology. So, there is great signification in the research of regeneration and utilization of zeolite synthesized with fly ash. My research can resolve the problems of occupying land and polluting environment, which caused by fly ash that be throwed into field. On the other hand, utilizing the synthesized zeolite again can decrease the cost of treatment wastewater; the purpose of waste treated by waste was attained. More importantly, the regeneration by biological method promises a very high value in popularization and application, can be translate great economic and social benefits.