本研究為探討在不同的反應溶液、不同反應時間和預定加入Fe0劑量之次數條件下，合成氧化鐵覆膜石英砂吸附材料，並做其應用。在合成氧化鐵覆膜石英砂吸附材料之過程中，持續監控過程中之pH、ORP、DO的變化，並且分析多種型態材料之特性。除此之外，將合成氧化鐵覆膜石英砂吸附材料應用於吸附去除五價砷【As﹙V﹚】。由實驗得知，相同Fe0劑量下，當個別地在 0、6、24、30小時分別加入2、4、6 g之Fe0所合成之氧化鐵覆膜石英砂比其他單一次加入Fe0劑量所合成之氧化鐵覆膜石英砂擁有高含量之氧化鐵覆膜於石英砂上。當硫酸亞錳溶液為反應溶液時，增加反應溶液之濃度對於氧化鐵覆膜在石英砂上有抑制的作用。當矽酸鈉溶液為反應溶液時，增加反應溶液濃度對於氧化鐵覆膜在石英砂上有增進的作用。在去除五價砷之結果比較上，以在矽酸鈉溶液為8 ppm所合成之氧化鐵覆膜石英砂，可去除50 % 之五價砷【As﹙V﹚】，為五價砷【As﹙V﹚】去除之最佳吸附劑。其次為在矽酸鈉溶液為2、4 ppm所合成之氧化鐵覆膜石英砂，可去除45 % 之五價砷【As﹙V﹚】。在其次為在矽酸鈉溶液為1 ppm及在硫酸亞錳溶液為1、2、4 ppm所合成之氧化鐵覆膜石英砂，可去除40 % 之五價砷【As﹙V﹚】。 This Study describes synthesis and application of environmental adsorptive iron-oxide pellets under different conditions of reaction solutions, reaction times, and step additions of predetermined amount of Fe0. In the process of iron-oxide pellets synthesis, variations of pH, ORP, DO were monitored continuously. Characteristics of various types of iron-oxide pellet were analyzed. In addition, such iron-oxide pellets were applied for adsorptive removal of arsenate species. The results show that step additions of predetermined amount of Fe0 at 0 , 6 , 24 , 30 hr, respectively, for iron-oxide pellets synthesis led to higher amount of iron-oxide coated onto sand than the other type of single step addition of Fe0 with the same overall dosage. With Mn2SO4‧H2O as background species, increase of its concentration resulted in the decrease of amount of iron-oxide coated onto sand. In the case of Na2SiO3 , as its concentration increased, amount of iron-oxide coated onto sand increased as well. In comparison of arsenate removal performance, the best adsorbent synthesized with the presence of 8 mg/L of Na2SiO3 can remove arsenate by 50 %. As for the one with the presence of 2,4 mg/L of Na2SiO3 , the arsenate can be removed by 45 %.
