A simulation of sewer biodeterioration by analysis of different components with a model approach

This paper represents the first study to simulate the biodegradation rates (BDRs) of several components in the sewer using the sewer biodegradation model (SBDM). In order to verify the fitness between the experimental values and model values, experiments were conducted in a 21 m long sewer pilot plant and the results showed high fitness (All correlational coefficient values were greater than 0.91). Since the SBDM was validated, the biodegradation rate (BDR) was simulated. The production of hydrogen sulfide was also simulated. The results revealed that aerobic growth of heterotrophs in biofilm predominated the biodegradation. The growth rate of heterotrophs in biofilm was greater than the decay rate from initial time to the 3rd hour, but it changed after the 4th hour because of low substrate concentration. During the experimental period, the BDRs were greater than the supply rate for five components. For two components, the supply rates were greater than the BDRs. The BDR of dissolved oxygen was greater than the supply rate before the 3rd hour but that reversed after the 3rd hour. According to the results, the sewer biodeterioration could be simulated using SBDM.