Prediction of Five-day Biochemical Oxygen Demand (BOD5) from Chemical Oxygen Demand (COD) Values in Raw and Biologically Treated Domestic Sewage

Short Communication: Domestic Sewage Treatment

  • Ita Erebho Uwidia Department of Chemistry, University of Benin, Benin City, Nigeria
  • Christopher Ejeomo
DOI: https://doi.org/10.52763/PJSIR.PHYS.SCI.58.3.2015.172.174
Keywords: prediction, BOD5, COD, correlation, regression analysis, domestic sewage, wastewater

Abstract

The functional relationship between BOD5 and COD was evaluated using domestic sewage samples collected from a sewage treatment plant in an estate in Warri, Delta State, Nigeria. Two types of samples were collected: raw domestic sewage,(influent) and biologically treated domestic sewage (effluent).The correlation coefficient r between the BOD5 and COD was determined and values were 0.99 and 0.94, respectively for different sewage samples. The regression analysis carried out showed very strong correlation . The linear correlation established was: COD = 1.62 BOD5 + 15.82 ; r2 = 0.978; COD = 1.58BOD5 + 9.21; r2 = 0.878. Results obtained above were also judged as significant at 95% and 99% confidence levels. Confidence intervals obtained were: 1.53£ a £1.71 at 95% and 1.49£ a £1.75 at 99% for the raw sewage; 1.37£ a £ 1.80 at 95% and 1.27£ a £1.90 at 99% for the biologically treated sewage. 

Published
2015-10-26
Issue
Vol 58 No 3 (2015): Pakistan Journal of Scientific and Industrial Research Series A: Physical Sciences
Section
Articles