Performance of anaerobic co-digestion with honey processing wastewater as co-substrate for treating synthetic wastewater containing commercial anthraquinone dye Remazol blue RSP: Effect of C:N ratio and HRT

Abstract

Anaerobic co-digestion (ACoD) using solid waste as co-substrate is inefficient for industrial wastewater treatment. This study investigated the effect of honey processing wastewater as a co-substrate on the performance of ACoD in treating synthetic wastewater containing commercial anthraquinone dye. The objective of this study was to determine the optimum C:N ratio and HRT in ACoD to obtain COD removal and decolorization efficiently. The experiment was conducted using laboratory UASB reactors with a total volume of 4.8 L inoculated with anaerobic granule and the variations of C:N and HRT were used. The result showed optimal configuration was obtained in 5:1 C:N ratio at 24 h HRT resulted in 76.69 ± 2.83 % COD removal and 97.37 ± 3.62 % decolorization. Metagenomic analysis showed that the optimal ACoD configuration was suitable for both COD removal and reductive decolorization, by the presence of phylum Halobacteriota (38.2 %), Euryacrhaeota (4 %), Desulfobacteriota (16 %), Actinobacteriota (10 %) and, other Bacterial phylum.