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Methanogenesis from wastewater stimulated by addition of elemental manganese.

Qiao S, Tian T, Qi B, Zhou J - Sci Rep (2015)

Bottom Line: The results indicated that elemental manganese effectively enhanced both the methane yield and the production rate.Besides, more acetate consumption and less propionate generation were observed during the methanogenesis with manganese.Further studies demonstrated that the elemental manganese served as electron donors for the methanogenesis from carbon dioxide, and the final proportion of methane in the total generated gas with 4 g/L manganese addition reached 96.9%, which was 2.1-fold than that of the control (46.6%).

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, P.R. China.

ABSTRACT
This study presents a novel procedure for accelerating methanogenesis from wastewater by adding elemental manganese into the anaerobic digestion system. The results indicated that elemental manganese effectively enhanced both the methane yield and the production rate. Compared to the control test without elemental manganese, the total methane yield and production rate with 4 g/L manganese addition increased 3.4-fold (from 0.89 ± 0.03 to 2.99 ± 0.37 M/gVSS within 120 h) and 4.4-fold (from 6.2 ± 0.1 to 27.2 ± 2.2 mM/gVSS/h), respectively. Besides, more acetate consumption and less propionate generation were observed during the methanogenesis with manganese. Further studies demonstrated that the elemental manganese served as electron donors for the methanogenesis from carbon dioxide, and the final proportion of methane in the total generated gas with 4 g/L manganese addition reached 96.9%, which was 2.1-fold than that of the control (46.6%).

No MeSH data available.


Manganous ions concentrations during the research operation.Error bars represent standard deviations of triplicate tests.
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f2: Manganous ions concentrations during the research operation.Error bars represent standard deviations of triplicate tests.

Mentions: Electrons, generally provided by hydrogen, were needed to accomplish the conversion from CO2 into CH4 with hydrogen as substrate23. Literatures had shown that several kinds of elemental metals could serve as initial electron donors for CH4 formation from CO2 through cathodic depolarization1516. In the present study, manganous ions in the liquid phase were determined to indicate whether the additional manganese could release electrons as donors for the methanogenesis and the results were shown in Fig. 2. The manganous ions concentration with 2 g/L manganese added increased slowly before 100 h and then became steady around 100 mg/L. However, as the concentrations of manganese increased to 4 and 8 g/L, the manganous ions production rates increased rapidly, and reached the peak about 75 mg/L at 36 h and 22 h, respectively. Then, the manganous ions concentration began to decrease. Particularly, it lowered to zero with 4 g/L manganese added at 96 h.


Methanogenesis from wastewater stimulated by addition of elemental manganese.

Qiao S, Tian T, Qi B, Zhou J - Sci Rep (2015)

Manganous ions concentrations during the research operation.Error bars represent standard deviations of triplicate tests.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4525485&req=5

f2: Manganous ions concentrations during the research operation.Error bars represent standard deviations of triplicate tests.
Mentions: Electrons, generally provided by hydrogen, were needed to accomplish the conversion from CO2 into CH4 with hydrogen as substrate23. Literatures had shown that several kinds of elemental metals could serve as initial electron donors for CH4 formation from CO2 through cathodic depolarization1516. In the present study, manganous ions in the liquid phase were determined to indicate whether the additional manganese could release electrons as donors for the methanogenesis and the results were shown in Fig. 2. The manganous ions concentration with 2 g/L manganese added increased slowly before 100 h and then became steady around 100 mg/L. However, as the concentrations of manganese increased to 4 and 8 g/L, the manganous ions production rates increased rapidly, and reached the peak about 75 mg/L at 36 h and 22 h, respectively. Then, the manganous ions concentration began to decrease. Particularly, it lowered to zero with 4 g/L manganese added at 96 h.

Bottom Line: The results indicated that elemental manganese effectively enhanced both the methane yield and the production rate.Besides, more acetate consumption and less propionate generation were observed during the methanogenesis with manganese.Further studies demonstrated that the elemental manganese served as electron donors for the methanogenesis from carbon dioxide, and the final proportion of methane in the total generated gas with 4 g/L manganese addition reached 96.9%, which was 2.1-fold than that of the control (46.6%).

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, P.R. China.

ABSTRACT
This study presents a novel procedure for accelerating methanogenesis from wastewater by adding elemental manganese into the anaerobic digestion system. The results indicated that elemental manganese effectively enhanced both the methane yield and the production rate. Compared to the control test without elemental manganese, the total methane yield and production rate with 4 g/L manganese addition increased 3.4-fold (from 0.89 ± 0.03 to 2.99 ± 0.37 M/gVSS within 120 h) and 4.4-fold (from 6.2 ± 0.1 to 27.2 ± 2.2 mM/gVSS/h), respectively. Besides, more acetate consumption and less propionate generation were observed during the methanogenesis with manganese. Further studies demonstrated that the elemental manganese served as electron donors for the methanogenesis from carbon dioxide, and the final proportion of methane in the total generated gas with 4 g/L manganese addition reached 96.9%, which was 2.1-fold than that of the control (46.6%).

No MeSH data available.