Activated carbon is usually used when removing acid gases such as NCh and SCh from atmosphere by air cleaning apparatus. Activated carbons have the property of desorbing NO when removing NO_2. Addition of various alkalis to activated carbon was tried to solve the problem. KOH was the most effective of all alkalis tested. The removal efficiency of KOH-added activated carbon against NO_2 was superior to that of an untreated activated carbon. Furthermore, a prediction method for breakthrough curves by numerical simulations was studied. The simulated breakthrough curves agreed well with the experimental results in both of constant condition and outdoor condition.
