Study on the inhibitory effect of mimosa extract on anaerobic fermentation

Concerning the treatment of tannery wastewater with high COD (chemical oxygen demand), the effective process is physical-chemical and anaerobic treatment. The core technology of anaerobic treatment is to test the performance of anaerobic degradation of organic matter, clarify the inhibitory effect and inhibitory mechanism of pollutant. In this paper, anaerobic degradation and inhibitory effect of mimosa extract were studied. In the course of the experiment, the production of methane, the activity of sludge, the content of coenzyme F420, the content of extracellular polymeric substances(EPS), the content of extracellular protein(EP) were been tested, the mimosa extract and degradation products were been tested by Fourier transform infrared spectroscopy (FT-IR). The results indicated that the 50% inhibitory concentration of mimosa extract is about 3.85 g/L, the anaerobic fermentation has been inhibited is owing to mimosa extract has the inhibition on methanogenic activity of methanogens, the production of methane, the activity of sludge and the content of coenzyme F420 are getting lower and lower with the increase in content of mimosa extract. The characterization of FTIR showed that the mimosa extract has been degraded in anaerobic fermentation. These all indicated that mimosa extract can inhibit the anaerobic fermentation, and the greater amount, resulting in stronger inhibition, in appropriate concentrations, mimosa extract can be degraded by anaerobic fermentation. The results can provide guidance for anaerobic treatment of tannery wastewater with high COD.