After 20 days of the start-up operation, the activity of the
sludge was detected every two days in the two reaction
zones. It was found that the dehydrogenase activity was
strong in the integrated two-phase anaerobic reactor, and
the activity of the dehydrogenase in the reaction zone I
and II was 131.4 – 142.3 lg/(g min) and 152.2 – 171.6 lg/
(g min), respectively. The protease activity decreased longitudinally
along the reactor from zone I to zone II. Then the
activity of protease in the two reaction zones were 25.35 –
27.56 mol/(gvs min) and 17.31 – 23.12 mol/(g min), respectively.
The protease activity demonstrated that hydrolysis
and acidogenesis were the main biochemical reactions occurring
in the zone I. And the hydrolysis acidification effect of
the soybean protein wastewater was enhanced in the reaction
zone I accelerating the process of the start-up
operation.