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|Authors: ||Jeng-Hung Tsai|
|Contributors: ||NTOU:Institute of Applied Geosciences|
|Issue Date: ||2011-06-30T08:08:52Z
|Abstract: ||在水產養殖業中，水的品質是最直接地影響到魚類生長的因素，因此欲讓魚類生長快速及品質優良，首要步驟即是改善水的品質。由於水中的NH3與NH4+會維持一定平衡，其主要毒性在於NH3，而去除NH4+有助於減少NH3的含量，所以本實驗利用各類沸石去除水中的NH4+，並且探討天然沸石及合成沸石的除銨機制與能力。本研究使用的天然沸石種類有斜髮沸石、菱沸石、毛沸石及絲光沸石等；而合成沸石有鋇十字沸石、P沸石、鈉-鈣十字沸石及鉀-鈣十字沸石等，共16個沸石樣本。銨離子水溶液之起始濃度為50ppm及20ppm，體積為500mL，放入5g沸石粉後，每6小時抽取溶液5cc，並利用離子層析儀、感應耦合電漿原子放射光譜儀以及分光光度計分析反應後水溶液中Na+、K+、NH4+之濃度。 實驗結果顯示天然沸石中，除銨效果最佳者為菱沸石，其除銨總量為40.9ppm，並且大部份的天然沸石在前6小時即除去大量的NH4+；而合成沸石之除銨速率較為緩慢，反應約在3天後趨於平緩。 沸石之除銨機制可區分為離子交換及物理性吸附，天然沸石主要是藉由前者的方式除去銨離子；合成沸石則是藉由後者的方式去除銨離子。研究結果顯示天然沸石中，其陽離子數愈高，除銨效果愈好，並且Si/Al比值為4.70時，除銨效果最差；Si/Al比值為3.09時，除銨效果最佳，而Si/Al比值大於5.00時，對於NH4+的吸附作用也隨著Si/Al比值增加而增強，因此除銨效果亦增加。|
In the aquatic products industry, high quality water effects the growth of the fishes immediately. Therefore, improving water quality is of the utmost importance for healthy and faster maturing fish. In water, however ammonia and ammonium will be equilibrium, and the main toxicity is derived from ammonia for the fishes. So we can use many kinds of zeolites to remove the ammonium in order to reduce the ammonia in water and probe the mechanisms and ability to remove ammonium using natural zeolites or synthetic zeolites. The natural zeolites we use in this experiment include clinoptilolite, chabazite, erionite, mordenite; the synthetic zeolites are Merlinoite, zeolite P, Na-phillipsite and K-phillipsite. There are sixteen zeolites samples in all. The intial concentrations of ammonium solution are 50ppm and 20ppm, and the volume of the solution is 500ml. After putting the zeolite powder of 5g into the solution, we sampled 5cc from the solution per six hours to analyz the concentrations of Na+, K+ and NH4+ by IC, ICP and Spectrophotometer. The results of the experiment show chabazite has the best ability of removal ammonium and can remove 40.9 ppm of ammonium in the initial NH4+ concentration of 50 ppm, and most natural zeolites remove a large amount ammonium at first six hours;. Synthetic zeolites have a lower rate of removing the ammonium and especially its removing ability will drop gentlely after three days of experiment. The mechanisms of removal ammonium include ion-exchange and adsorption. The natural zeolites mainly remove the ammonium in the water by the former, and the synthetic ones remove it by the latter. We also find that natural zeolites have more cations and a better ability to remove ammonium. When the Si/Al ratio is 4.7, the removal ability is at its worst; when the Si/Al ratio is 3.09, the removal ability is at its best; however, as the Si/Al ratio is greater than 5, the ability of NH4+ adsorption increases accordingly and the effect of removing ammonium increases as well.
|Appears in Collections:||[應用地球科學研究所] 博碩士論文|
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