在不同热处理温度(60℃、160℃)和热处理时间(2h、12h)条件下,通过负载不同质量分数的氯化铵、氟化铵、草酸铵、硫酸铵、过硫酸铵等无机铵盐溶液对活性炭纤维(ACF)进行改性实验,并利用扫描电镜(SEM)分析表征改性后的ACF,研究其对甲醛去除率的影响.结果表明,不同无机铵盐对ACF的改性效果良好,甲醛去除率均大于50%.其中,经草酸铵改性后的ACF对甲醛的去除率最高,可达67.7%.SEM观察发现,无机铵盐大多堆积在ACF表面,不能进入其孔径内部,减小了ACF与外界的接触面积,但对其吸附面积影响不大.因此,利用无机铵盐改性ACF来提高甲醛去除率是可行的.
We investigated the efficiency of formaldehyde removal by activated carbon filters (ACF) modified by inorganic ammonium salts, such as ammonium chloride,ammonium fluoride,ammonium oxalate,ammonium sulfate,ammonium persulfate, and triethanolamine. Many parameters, including mass fractions of different ammonium salts, heating temperatures (60℃ and 160℃) and heating times (2 h and 12 h) were examined for their effects on the removal efficiencies. The ammonium salts significantly enhance the ACF performance for formaldehyde removal, with efficiencies higher than 50%. Ammonium oxalate has the highest removal efficiency (67.7%) among all the investigated salts. SEM (scanning electron microscopy) images of ACF modified by ammonium salts indicate that a large quantity of the salts tend to accumulate on the surface of ACF, rather than to enter its pores. As a result, the exposure area of ACF is decreased, but its adsorption performance is little influenced. In conclusion, employing ACF modified by inorganic ammonium salts is a promising method of formaldehyde removal.