| | Control factor | | Level | | | 1 | 2 | 3 | 4 |
| | (A) Light source | UV | UV/LED | — | — | | (B) Catalyst type | TiO2 | 0.005 wt.% Pt/TiO2 | 0.025 wt.% Pt/TiO2 | 0.2 wt.% Pt/TiO2 | | (C) Concentration (ppmv) |
50
|
100
|
200
|
300
| | (D) Retention time (sec) |
40
|
60
|
80
|
100
| | (E) Photointention (Mw cm−2) |
1.55
|
1.62
|
2.1
|
2.4
| | (F) Relative humidity (%) |
0
|
5
|
15
|
45
|
|
|