不同活化溫度孟宗竹活性碳應用於飲用水質之改良

Improvement of Drinking Water Qualities by Using Moso Bamboo Activated Carbon Made from Different Activation Temperatures

本試驗係先將孟宗竹利用機械窯在升溫速率25℃／hr下，加熱至500℃，並持溫1hr，得到孟宗竹炭，再將其以活化爐在氮氣流量15mL／min下，將竹炭以升溫速率10℃／min，再通入流量33mL／min之水蒸氣，分別依不同活化溫度700、900及1000℃，活化時間1hr，製成活性碳，並與市售活性碳比較其基本性質與分析其應用飲用水質之改善效果。試驗結果發現，活性碳之收率隨活化溫度之升高而降低，真密度、孔隙度、碳元素含量及比表面積均隨活化溫度之升高而增加，但酸鹼值差異不大，活性炭微孔之平均孔隙直徑約20.0Å左右。以竹活性炭處理均可使水質具鹼性，並可溶入高濃度鉀離子，以900℃以上活化之竹活性碳才可將水中鈣及鎂離子去除，使硬水或中水變成軟水。孟宗竹活性碳處理後，以較高溫活化溫之活性碳對硝酸態氮的吸附效果較佳，可降低水中硝酸態氮含量。整體而言，孟宗竹竹活性碳對水質較差之地下水的改善效果優於水質較佳之自來水。 In this study, the moso bamboo charcoals was first obtained using a steel kiln at a heating rate of charcoalization of 25℃/hr for a temperature of 500℃ and holding time of 1 hr. Then the activated carbons made from moso bamboo charcoal using a activated furnace under conditions of N2 inlet flowing rate of 15 mL/min, heating rate of 10℃/min and steam injection flowing rate of 33 mL/min, three different activation temperatures of 700, 900, and 1000℃ and activation time of 1 hr were carried out, respectively. The fundamental properties of the activated carbons comparison with commercial one and the improved efficiency of tap and ground drinking water qualities by treated with the moso bamboo activated carbon were examined. The results showed that the yield of activated carbons decreased with increasing activation temperatures, while the solid density, porosity, content of carbon and specific surface area increased with increasing activation temperatures. However, the pH value was not significantly different and the average pore diameter was about 20.0 Å. The results also indicated that the drinking water possessed more alkalinity, more concentration of K^+ was soluble in water after moso bamboo activated carbon treatments. The Ca2+ and Mg2+ could be removed only by treated with activated carbon made from activation temperature over 900℃, i.e. hard water or moderately hard water would be become to a soft water. The results also found that the activated carbon made form higher activation temperature had superior adsorption efficiency on NO3-N. Generally speaking, the improved efficiency of bamboo activated carbon treatments for poor quality of ground water was better than that of the superior quality of tap water.

In this study, the moso bamboo charcoals was first obtained using a steel kiln at a heating rate of charcoalization of 25℃/hr for a temperature of 500℃ and holding time of 1 hr. Then the activated carbons made from moso bamboo charcoal using a activated furnace under conditions of N2 inlet flowing rate of 15 mL/min, heating rate of 10℃/min and steam injection flowing rate of 33 mL/min, three different activation temperatures of 700, 900, and 1000℃ and activation time of 1 hr were carried out, respectively. The fundamental properties of the activated carbons comparison with commercial one and the improved efficiency of tap and ground drinking water qualities by treated with the moso bamboo activated carbon were examined. The results showed that the yield of activated carbons decreased with increasing activation temperatures, while the solid density, porosity, content of carbon and specific surface area increased with increasing activation temperatures. However, the pH value was not significantly different and the average pore diameter was about 20.0 Å. The results also indicated that the drinking water possessed more alkalinity, more concentration of K^+ was soluble in water after moso bamboo activated carbon treatments. The Ca2+ and Mg2+ could be removed only by treated with activated carbon made from activation temperature over 900℃, i.e. hard water or moderately hard water would be become to a soft water. The results also found that the activated carbon made form higher activation temperature had superior adsorption efficiency on NO3-N. Generally speaking, the improved efficiency of bamboo activated carbon treatments for poor quality of ground water was better than that of the superior quality of tap water.