Biodegradation Potential of Some Bacteria and Fungi Isolates from Septic Tank Sewage in Some Related Sites in Delta and Edo States of Nigeria

The biodegradation potentials of some selected bacteria isolated from septic tank sewage in the region under study were examined. Three replicate samples from Locations A, B and C representing Agbor, Benin and Sapele regions of Delta and Edo States, Nigeria respectively were collected from the influent tank (raw sewage) between November 2018 and January 2019 for testing. The sewage in 10 ml septic tubes for both experimental and control samples was subjected to shake flask biodegradation analysis using the isolates with the highest screen test result. A total of 18 bio-treatment options were available in this study. In the shake flask biodegradation of sewage using isolates, total organic carbon (TOC) values from day 0 to 25 in all isolates were lower compared with the control experiments. TOC values at day 25 were lowest (0.10 mg/L) in the treatment containing Bacillus sp. + Klebsiella sp. as compared to the TOC value (2.01 mg/L) of the treatment which had Aeromonas sp. + Bacillus sp. + Klebsiella sp. pH, EC, COD, TDS, DO and BOD were also monitored for a period of 3 weeks. In all treatment options, there was a rapid increase in the BOD for the experimental set up around day 10 - 20 which ranged between 74.82 - 187.54 mg/L. The overall physical observation (odour, consistency and colour) of the experimental and the control septic tubes showed very high remarkable reductions in the experimental set-up when compared with the observation made for the control samples.