单宁活性炭对甲醛的吸收研究

Research of Formaldehyde Absorbed by Tannin and Activated Carbon

[目的]探讨单宁活性炭对甲醛吸附的最佳反应条件。[方法]研究了吸附有青柿子粉的活性炭对甲醛的吸附反应特性,分析青柿子粉浓度、温度、反应时间、pH等反应条件对青柿子粉单宁吸附甲醛效果的影响。[结果]pH对活性炭吸附甲醛反应的影响最显著,温度次之,反应时间的影响最小;青柿子粉浓度越高,甲醛的减少量越大;当反应温度为30℃时,甲醛减少量最大,随着反应温度的继续升高,活性炭会发生脱附,导致甲醛去除率降低;当反应时间为4 h时,甲醛减少量最大,反应时间逐渐延长后甲醛减少量趋于平缓,吸收甲醛后并不会因为时间的积累而又解吸出来,吸收较为稳定。[结论]单宁活性炭吸附甲醛的最佳条件为:青柿子粉用量为4 ml,pH=1.0,反应温度为30℃,反应时间为4 h。

[Objective] The study aimed to discuss the optimal reaction conditions of formaldehyde absorbed by tannin and activated carbon.[Method] The absorption reaction characteristics of formaldehyde by activated carbon adsorbing green persimmon power were studied,as well as the removal efficiency of formaldehyde under the conditions of different tannin dosages,temperatures,reaction times and pH.[Result] The influence of pH on the adsorption reaction is most obvious,followed by temperature and reaction time;the removal efficiency of formaldehyde increases with the increase of tannin dosage;the efficiency is the highest when temperature is 30 ℃,and it decreases with the increase of temperature because of activated carbon stripping;the efficiency is the maximum as reaction time is 4 h,and it becomes mild with the increase of reaction time.In addition,the formaldehyde absorbed by tannin will not be parsed over time,that is,the absorption is relatively stable.[Conclusion] The removal efficiency of formaldehyde by tannin and activated carbon is the highest when tannin dosage is 4 ml,pH=10,reaction temperature is 30 ℃,and reaction time is 4 h.