Fig. 10

Methane production vs wall-shear stress, COD = 200 mg/L. In order to validate the model, the measured data was used when COD was 200 mg/L. The fitting results were showed. Results showed the model’s predictions, agreed with the measurements well, the difference between measurement and simulation was found in the rage of 1.5–13.0%. In this model, substrate concentration and pipe size were not considered that leaded to some errors between measurement and simulation. And it would be revised in our future research