Biodegradation of septic tank fecal sludge using Priestia aryabhattai

The significant potential of microorganisms for fecal sludge degradation is an interesting area for investigation, primarily due to its current lack of attention. This study involved the identification of indigenous bacteria in septic tank fecal waste with the Polymerase Chain Reaction (PCR) 16S rRNA gene. Subsequently, selected bacteria strains were subjected to a potential assessment using a single method. Variables in this experiment included the addition of 2% (v/v) bacteria and sample sterilization. The results showed that the use of PCR 16S rRNA analysis led to the identification of Priestia aryabhattai, a member of the phylum Firmicutes, as the dominant species in the samples. This bacteria exhibited adaptability to both aerobic and anaerobic conditions. Sterile samples with the addition of P. aryabhattai 2% (v/v), showed the best removal efficiency percentages of 79.77%, 79.62%, 62.91%, and 70.48% for Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD), Total Suspended Solids (TSS), and Volatile Suspended Solids (VSS). Meanwhile, the total carbon and nitrogen decreased to 2895 mg/L C and 794.12 mg/L NH3-N, respectively. Based on the results, Priestia aryabhattai has the potential to degrade organic waste but is not suitable for fecal sludge.