Mechanish research on performance of EGSB reactor at low temperature

To research the performance mechanism of the EGSB reactor at low temperature, the influence of temperature and liquid up-flow velocity (V_up) on the performance of the EGSB reactor and on the methanogenic activity of the granular sludge were studied. And then changes of the rate constant K and the activation energy E in the EGSB reactor at different temperatures and varied V_up were analyzed. The result stated that lowering the operation temperature led to an obvious decrease in the granular sludge methanogenic activity and the COD removal efficiency. The rate constant K of the EGSB reactor at 35°C, 15°C (with an equal V_up to 35°C) and 15°C (with an optimal K_up) was 0.391 × 10³ d^-1, 0.107 × 10³ d^-1 and 0.254 × 10³ d^-1, respectively. The activation energy E of the EGSB reactor was 4.897 × 10⁴ J/mol and 1.197 × 10⁴ J/mol before and after increasing V_up. Lowering the operation temperature of the EGSB reactor caused the obvious decrease of the granular sludge methanogenic activity, the COD removal efficiency and the rate constant K. But heightening V_up could improve the rate constant K and decrease the activation energy E apparently. And thus the EGSB reactor could remain high removal efficiency at low temperature of 15°C.