title: Microbiological studies of an anaerobic baffled reactor: microbial community characterisation and deactivation of health-related indicator bacteria.
abstract: This WRC funded project has studied the appropriateness of the ABR (anaerobic baffled reactor) for on-site primary sanitation in low-income communities. A 3,000 L pilot reactor was located at the Kingsburgh wastewater treatment plant south of Durban, South Africa. Feed to the reactor was raw domestic wastewater containing a significant proportion of particulate organic matter. The compartments of the ABR were routinely monitored for pH, COD, and gas production, among other physical-chemical determinants. The microbial population in each compartment was analysed by fluorescent in situ hybridisation, using general oligonucleotide probes for eubacteria and archeae and a suite of 10 genera or family specific probes. Scanning electron microscopy was conducted on the sludge fraction of each compartment. Mixed fractions from each compartment were also analysed for health-related indicator bacteria (total coliforms and E. coli). Results indicated that methanogenesis was not occurring to the expected extent in the latter compartments, and that this was probably due to a hydraulic load limitation. This contrasted with earlier studies on industrial effluent, for which the organic load was exclusively in soluble form. Inactivation of health-related indicator bacteria was less than 1 log, indicating the need for an additional post-treatment of the effluent to protect community health.
authors.affiliation: Centre for Water and Wastewater Technology, Durban Institute of Technology, Durban, 4000, South Africa.
authors.forename: T
authors.initials: T
authors.lastname: Lalbahadur
authors.forename: S
authors.initials: S
authors.lastname: Pillay
authors.forename: N
authors.initials: N
authors.lastname: Rodda
authors.forename: M
authors.initials: M
authors.lastname: Smith
authors.forename: C
authors.initials: C
authors.lastname: Buckley
authors.forename: F
authors.initials: F
authors.lastname: Holder
authors.forename: F
authors.initials: F
authors.lastname: Bux
authors.forename: K
authors.initials: K
authors.lastname: Foxon
mesh_terms: D001421:Bacteria, Anaerobic / Q000254:growth & development*; D019149:Bioreactors; D004269:DNA, Bacterial / Q000032:analysis; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D011634:Public Health; D012499:Sanitation / Q000191:economics / Q000379:methods*; D013019:South Africa; D014865:Waste Disposal, Fluid / Q000191:economics / Q000379:methods*; D014871:Water Microbiology
chemical_list: D004269:DNA, Bacterial