Pretreatment of piggery digestate wastewater by ferric-carbon micro-electrolysis under alkalescence condition

Abstract Due to the low COD/TN ratio, piggery digestate wastewater is non-biodegradable and pathogenic; its advanced treatment is becoming a wide-spread environmental concern. In this study, the process of Fe-C micro-electrolysis was applied to pretreat piggery digestate wastewater. Fe-C micro-elect...
Ausführliche Beschreibung

Abstract Due to the low COD/TN ratio, piggery digestate wastewater is non-biodegradable and pathogenic; its advanced treatment is becoming a wide-spread environmental concern. In this study, the process of Fe-C micro-electrolysis was applied to pretreat piggery digestate wastewater. Fe-C micro-electrolysis was confirmed effectively to enhance biodegradability of the piggery digestate wastewater. Response surface methodology (RSM) was employed to study the interactions between factors and optimize operating parameters. The optimum conditions for Fe-C micro-electrolysis were found to be 150 g/L of dosages of Fe-C particles, 6 L/h of aeration rate and 9 h of hydraulic retention time at pH 7.6, respectively. Under these conditions, the obtained chemical oxygen demand (COD) removal efficiency was 52.62%, and the ratio of BOD/COD increased from 0.13 to 0.285, which showed improvement of biochemical property. Furthermore, SEM analysis indicated the surface configuration of Fe-C particles. More important, this process could effectively pretreat the piggery digestate wastewater and avoid the generation of secondary pollution. Ausführliche Beschreibung