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The performance of anaerobic single baffled reactor (ASBR) with varying VFA concentrations

Wibisono, G., Cord-Ruwisch, R. and Ho, G.ORCID: 0000-0001-9190-8812 (1999) The performance of anaerobic single baffled reactor (ASBR) with varying VFA concentrations. In: International Regional Conference on Environmental Technologies for Wastewater Management, 4 - 5 December, 1997, Perth, Western Australia pp. 269-275.

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The performance of two identically shaped laboratory scale anaerobic reactors was tested for volatile fatty acids (VFAs) removal. The control reactor simulated a septic tank, while the test reactor had a baffle separating the reactor into two compartments (inlet and outlet compartment) with an opening at the bottom. Both reactors were fed with an identical feed of acetic, propionic and butyric acids at concentrations of 2mM.

Within less than 3 weeks, the anaerobic single baffled reactor (ASBR) showed that its performance was superior to the simulated septic tank. The ASBR degraded nearly 100% of VFAs, while the control could only degrade about 40%. Also at higher VFA concentrations the ASBR resulted in a much better effluent.

The results clearly indicated that the design of typical septic tanks did not lend itself to degradation of pollutants, but to solids settling. The introduction of a single baffle with an opening at the bottom (ASBR) improved the biomass feed contact time and provided better mixing between bacteria and substrate and gave a better effluent quality.

After gradually decreasing the hydraulic retention time, from 50 down to 6 hours, the build-up of acetic and propionic acids decreased the ASBR performance to about 55% VFA removal. At these retention times hardly any VF A degradation would be expected in septic tanks.

Item Type: Conference Paper
Murdoch Affiliation(s): School of Biological and Environmental Sciences
Publisher: UNEP-IETC and Murdoch University
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