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.