The purpose of this study was to obtain a relationship between the ratio of
BOD/COD and partition coefficient octanol/water (Pow) for glucose, lactose, sucrose,
formaldehyde, acetic acid and oxalic acid. This relationship was supported by the
toxicity test of each organic material on fish. The results show that the lower the
BOD/COD ratio, the higher the Pow coefficient, which means more organic matter
leads to biomass. Among the organic materials studied, formaldehyde has the lowest
BOD/COD ratio (<0.1) and highest Pow (>4) and was supported by the results of its
toxicity in fish having the lowest LC-50 (24 mg/L). Whereas lactose has the highest
BOD/COD ratio (>0.9) and lowest Pow (<0.7) with the highest LC-50 (851 mg/L). The
rest of the organic substances have characteristics in the range of lactose and
formaldehyde.