TOC is an index of the total amount of organic substances present
in water/wastewater. TOC measurement plays a key role in
assessing the efficiency of a wastewater purification process. It is
used in a wide array of applications from management of wastewater
treatment plant influent and effluent, to drinking water supply
management, and monitoring of impurities in process and surface
waters. The determination of TOC content in water is useful as a
measure of pollution. In the present study, TOC removal was
noticed in SW irrespective of the carbon concentrations studied
suggesting the system’s function towards treatment. Among the
different carbon concentrations, 5 g/l illustrated higher TOC
removal (88 ± 4%) followed by 10 g/l (86 ± 4%), 15 g/l (80 ± 6%),
20 g/l (68 ± 5%), 30 g/l (47 ± 5%), 40 g/l (28 ± 6%), 50 g/l (25 ± 4%)
and 60 g/l (15 ± 6%). Bacteria grown with lower carbon concentrations
showed higher TOC removal than higher carbon concentrations.
Lower TOC removal at higher carbon concentrations
might be due to the inhibition of bacterial growth by VFA
present in SW. This was supported by growth curve results,
where lower substrate concentrations took short time, and higher
substrate concentrations took more time to show maximum
growth.