Immobilization Method For Methanosarcina And The Application Of Immobilized Methanosarcina In Strength Organic Wastewater Treatment

There are many shortcomings in anaerobic strength organic wastewater treatment with immobilized Methanosarcina. In this paper a new immobilization method is presented and strength organic wastewater is digested using immobilized Methanosarcina.During the strength organic wastewater digestion, the immobilized Methanosarcina can startup anaerobic digester quickly and efficiently. The COD of strength organic wastewater can be removed more satisfactorily with steady operation of the anaerobic reactor by immobilized Methanosarcina than that by free cells. In the artificial wastewater treatment, HRT of immobilized-cell reactor is 55.68 h on the last reaction day. The average COD load is 2.56 kgCOD/m3.d (1.41 times that of the free cells) and the highest load is 4.36 kgCOD/m3.d.The average COD removal rate is 84.70%(1.21 times than of the free cells).The average gas production rate is 1.80L/L. d (1.799 times that of the free cells) and the highest gas production rate is 3.2L/L.d. In the soybean cake wastewater treatment, the average COD load is 10.02 kgCOD/m3.d (1.88 times that of the free cells) and the highest load is 26.06 kgCOD/m3.d. The average COD removal rate is 85.34% (1.332 times that of the free cells) . The average gas production rate is 4.04L/L.d and the highest gas production rate is 9.5L/L.d. The methane content is 76-78%. The acetic acid content is below 0.2% and pH keeps 7.0-7.5.NaNO3 is used as coagulant agent instead of boric acid to entrap Methonasarcina in the study. It shows that the immobilization process is harmless to the cells. And the media can conglutinate totally. During the anaerobic ferment, the immobilized balls are not conglutinate and dissolved ,and keep good intensity. The balls don't swell obviously and only a few float.