微型舱模拟室内环境中活性炭净化甲醛的能力

利用微型实验舱(0.04 m3)模拟室内甲醛环境进行活性炭吸附实验,研究吸附后甲醛浓度随时间的变化趋势,计算活性炭对甲醛的净化效率、吸附速率和饱和吸附量,探索活性炭对室内甲醛的吸附规律.研究发现,当甲醛含量为0 ～0.40 mg,活性炭用量为0.5g时,舱内甲醛浓度随时间延长呈指数递减变化趋势,吸附后0～0.5 h甲醛浓度递减得最快,0.5～2h递减速度变缓,2～4h甲醛浓度基本上保持不变;研究E0A1、E1A4曲线斜率K及活性炭甲醛净化效率发现,每次吸附过程活性炭吸附2h可达到吸附平衡,活性炭进行3次吸附平衡即可达到吸附饱和,每次实验第一次吸附过程、每次吸附过程前半小时活性炭对甲醛的吸附能力最强;活性炭的吸附速率在吸附初期迅速降低,最后趋近于0;等量椰壳活性炭在一定浓度的污染物环境中饱和吸附量是个定值.说明使用活性炭净化室内甲醛有一定的规律可循.

Purification capacity of activated carbon for formaldehyde in simulating indoor environment of micro-chamber

The adsorption experiments of indoor formaldehyde on activated carbon were taken in a micro-test chamber (0.04 m³) which could be used to simulate the indoor environment. The purification efficiency, adsorption rate and saturated adsorption capacity of indoor formaldehyde on the activated carbon were calculated by measuring the trend of formaldehyde concentration over time, then the adsorption law of indoor formaldehyde on activated carbon was studied. The results showed that the formaldehyde concentration decreased with time exponentially when the amount of formaldehyde used was in the range of 0~0.40 mg and the amount of activated carbon was 0.5 g. After adsorption, the formaldehyde concentration decreased rapidly in the first half an hour and then decreased smoothly and eventually. The concentration remained essentially unchanged after 2 hours. By analyzing the purification efficiency of activated carbon and comparing the slops K of the curves E₀A₁ and E₁A₄, it was revealed that the adsorption equilibrium of activated carbon could be achieved after 2 hours and the saturated adsorption status could be achieved after three adsorption equilibrium processes by analyzing the purification efficiency of activated carbon and comparing the slops K of the curves E₀A₁ and E₁A₄. In the three adsorption equilibrium processes, the adsorption ability of activated carbon was the best in the first process. In each single adsorption equilibrium process, the activated carbon possessed the best adsorption ability in the first half an hour. The absorption rate of activated carbon was the largest in the initial period of time and then decreased rapidly to zero. The saturated adsorption capacity was constant for a certain amount of coconut shell activated carbon in an environment with pollutant in a certain concentration. It was proved that using activated carbon to purify the indoor formaldehyde had revealed a certain law.