Mathematical modelling for bio-nutrient removal during anaerobic sewage treatment using Acti-zyme as biocatalyst for sustainable sewage treatment

Abstract

This paper presents the mathematical modelling for bio-nutrient removal from sewage after applying Acti-zyme as a bio-catalyst at various retention times and Acti-zyme loadings. The bio-nutrient removal was measured through the removal of the sewage bio-contaminants i.e. chemical oxygen demand to the biochemical demand ratio (COD/BOD5), the BOD to the total Kjeldahl nitrogen ratio (BOD5/TKN), the COD/TKN ratio and the COD to the total phosphates ratio (COD/TP). Experiments were carried out in 250 mL flasks with a 75% working volume anaerobically incubated with temperature fixed at 37 °C and agitation of 60 rpm. The Acti-zyme loadings were varied between 35-70 g/m3 whilst the residence time was varied between 0-60 days. The COD/BOD5, BOD5/TKN, COD/TKN and COD/TP ratios obtained were > 1.2, 4.0, 8.0 and 15 respectively. COD/BOD5, BOD5/TKN, COD/TKN and COD/TP models with R2 > 0.90 in the form: