Influence of baffle orientation on the start up of anaerobic ponds for low strength domestic wastewater treatment

The start up of a horizontally baffled anaerobic pond (HBAP) and a vertically baffled anaerobic pond (VBAP) was investigated for the treatment of low strength wastewater. Effective particulate removal of 63% recorded for the HBAP indicated sedimentation as the principal removal mechanism. However, negative soluble COD (sCOD) removal indicated particulate degradation and the subsequent release of solubilised organic carbon. In contrast, the VBAP recorded superior sCOD removal, though was less effective for particulate removal. This implies that the enhanced mixing generated by the vertical baffles increased biomass contact but reduced particulate retention. Importantly, the study demonstrated that start-up of anaerobic ponds for treatment of low strength domestic wastewater is achievable. The constraining conditions presented in northern hemispheric applications exacerbate the need for biomass retention and improved contact to reduce the readily amenable carbon, it is thus posited that future AP design can be enhanced by incorporating both baffle orientations.