Microbial and Physicochemical Qualities of Septic Tank Wastewater: An Evaluation.

  • Ifeanyi Mirian Oyem, PhD University of Delta, Agbor
  • Hector Henry Oyem, PhD University of Delta, Agbor
  • Emmanuel Esosa Imarhiagbe, PhD University of Benin
Keywords: Septic Tank, Raw Sewage, Semi-Treated Sewage, Physicochemical, Microbial Qualities
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The physicochemical and microbial qualities of septic tank effluent samples from households within the study area were evaluated.  Three replicate samples from Locations A, B, and C representing Agbor, Benin City, and Sapele regions of Delta and Edo States, Nigeria were collected from both the inlet tank (raw sewage) and the outlet chamber (semi-treated sewage) for physicochemical and microbiological analyses using standard methods. Results of the physicochemical analyses showed that pH values ranged from 6.5 – 7.7 across locations and in both the raw and semi-treated samples. Electrical conductivity (EC), Total suspended solid (TSS) and BOD was significantly higher (p>0.05) in the raw sewage (RS) than in the semi-treated (SS), while DO was higher (p>0.05) in the SS in all three locations sampled. Microbial analysis shows that total heterotrophic bacteria (THB) was highest in the RS in two locations. Microbial isolates from wastewater samples included Staphylococcus aureus, Proteus mirabilis, Escherichia coli, Pseudomonas aeruginosa, and Aspergillus niger. DO was low at an average of 3.20 and 3.73 mg/L in both chambers of the septic tank. Average BOD5 of 59.4 and 42.8 mg/L and COD average of 206.8 and 153.2 mg/L were reported for the RS and SS chambers. 0.3 was the value of the ratio of BOD5/COD for the RS and SS in the study. This infers that biodegradation was slow and inefficient in the septic tank system, and that modification of the design is recommended to increase retention time in the RS chamber


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10 November, 2021
How to Cite
Oyem, I., Oyem, H., & Imarhiagbe, E. (2021). Microbial and Physicochemical Qualities of Septic Tank Wastewater: An Evaluation. East African Journal of Health and Science, 4(1), 41-60. https://doi.org/10.37284/eajhs.4.1.469