Microbial regrowth, microbial growth after disinfection, is an important problem that deteriorates water quality during the storage and distribution of reclaimed water. Biodegradable organic matter (BOM) that remains after water reclamation processes directly promotes microbial regrowth. In this study, we propose a novel assay called the ‘Bacterial Growth Fingerprint (BGF)’ to characterise BOM based on the maximum growth of bacterial strains, which is the extension of the conventional assimilable organic carbon assay for drinking water. Nine bacterial strains were selected from nearly 200 isolates from various reclaimed water systems. These selected bacterial strains exhibited unique substrate utilisation patterns. The BGF assay clearly reflected the difference in the quantity and quality of BOM between six different reclamation plants and the changes in BOM during a full-scale reclamation process. The information on BOM revealed by the BGF assay is useful to optimise the treatment processes or operational conditions for biologically stable reclaimed water.
- assimilable organic carbon (AOC)
- bacterial growth fingerprint (BGF)
- biodegradable organic matter (BOM)
- reclaimed water
- substrate utilisation
- water reclamation process
- First received 3 June 2015.
- Accepted in revised form 30 March 2016.
- © IWA Publishing 2016