Study On The Application Of Improving The Methanogens Activity

Anaerobic fermentation was carried out to improve the activity of methane-producing bacteria and the gas production by trace metal on the stroma of acetic acid. The results of parallel experiments indicated that the optimum trace metal combination is FeCl2·4H2O, CoCl2·6H2O and NiCl2·6H2O. And the result of orthogonality experiment determined the optimum dosages were FeCl2·4H2O 1.5 mg/L·d, CoCl2·6H2O 0.15 mg/L·d, NiCl2·6H2O 0.3 mg/L·d respectively.On the stroma of corn-ethanol production waste water, the result of the gas production comparison between the intermittent and continuous anaerobic fermentation indicated that the latter is 70% higher than the former.The optimum supplement dosage is determined by single trace metal salt that FeCl2·4H2O 1.5 mg/L·d, CoCl2·6H2O 0.15 mg/L·d, NiCl2·6H2O 0.3 mg/L·d, and the rate of gas rise is 97%, and the COD degradation rate is 81%.The comparison of the full-scale experiment between the completely mixed reactor and the EGSB reactor indicated that their rate of gas rise and the COD degradation rate were both improved, but the latter is higher, and the rate of biogas rise is 19.75%, and the COD degradation is 9.68%. Thus, EGSB reactor is fit for corn-ethonol wastewater disposal better.Economic analysis of EGSB reactor with compound trace metal salt indicated that if the effective volume was 2000m3 , $21555 could be saved and $3555 could be saved than it without trace metal. Thus the result indicated that wastewater loading, biogas production and COD degradation all can be improved if trace metal salt is added, and we can save a lot of fund.