The inconsistency between the theoretical ratio (2.396) and the practical ratio (2.201) indicate that conversion to carbon dioxide was not only outcome of the carbon source in biofilter.
The ratio of the production of carbon dioxide to BTEX consumed (EC) was approximately 0.171.
With a higher influent BTEX concentration, both loading rate and elimination capacity of BTEX were higher leading to the production of even more CO2. However, Fig. 4 clearly revealed that the CO2 evaluation and elimination capacity continued to rise with the loading rate.
In the other study (Shukla et al., 2010), it was showed that on an average 0.37 g m3 h1, CO2 was produced per one gm3 h1 of pollutant (TCE) degraded in the biofilter.