Enhanced Methane Production in an Anaerobic Continuous Stirred Tank Reactor by Adding Nitrilotriacetic Acid to Increase the Activity of Methanogenic Bacteria

摘要

The enbancement of methane production in an anaerobic continuous stirred tank reactor (CSTR) by adding nitrilotriacetic acid (NTA) was investigated in this study. The reactor was operated for 41 days at the condition of a COD concentration of 4000 mg/L, a bydraulic retention time (HRT) of 18 h under (35±1) °C. The results showed that the COD removal efficiency could be maintained at about 60% after 16 days of operation wben the feed wastewater had no NTA While, when 10 μmol/L NTA was added to the feed wastewater, the methane production of the reactor was increased from 14.3 to 27.4L/d and the COD removal efficiency achieved 80%. Simultaneously, the acetate, propionate and butyrate concentration were decreased to 305, 217, 17mg/L, respectively. The experiment of specific methanogenic activity tests found that the addition of NTA could increase the bioavailability of trace metal elements and the methane yield was enhanced. It can be concluded that the operational strategy of addition NTA was a feasible way to enhance the methane production and it could be applied in industrial wastewater treatment