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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.


Comparison of (a) acetic acid and (b) propionic acid concentrations with different dosages of elemental manganese addition. Error bars represent standard deviations of triplicate tests.
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f6: Comparison of (a) acetic acid and (b) propionic acid concentrations with different dosages of elemental manganese addition. Error bars represent standard deviations of triplicate tests.

Mentions: VFAs concentrations were determined during the whole operation period and only acetate and propionate were detected in the liquid phase. The production and consumption of these two kinds of VFAs were shown in Fig. 6. Simple organics could be rapidly fermented to volatile acids under anaerobic conditions18, thus, both the acetate and propionate were produced within 12 hours with glucose served as substrates. With manganese addition, significant differences in acetate concentrations were observed in the present study (Fig. 6a). The acetate concentrations of control fluctuated between 450 mg/L and 600 mg/L and the small amount consumption of acetate, one of the substrates for methanogens, was consistent with the CH4 production during the research (Fig. 1a). However, with 2 g/L manganese added, the acetate concentration dropped to 0 mg/L at 84 h. As a result, the CH4 production rate increased distinctly during this period (Fig. 1a). The increase in the manganese concentration to 4 g/L resulted in a reduction in the acetate at 12 h, which was only about 250 mg/L, just 45.5% of the control. Besides, it was similar with the former that the acetate concentration decreased to 0 mg/L at 84 h. The acetate concentration with 8 g/L manganese added changed intricately. Though a reduction in acetate generation was also found at 12 h, the concentration increased suddenly at 60 h after a period of stationary phase, and then it declined slowly. It was assumed that some inhibitory effects on the methanogenesis occurred in the digestion system.


Methanogenesis from wastewater stimulated by addition of elemental manganese.

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

Comparison of (a) acetic acid and (b) propionic acid concentrations with different dosages of elemental manganese addition. 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

f6: Comparison of (a) acetic acid and (b) propionic acid concentrations with different dosages of elemental manganese addition. Error bars represent standard deviations of triplicate tests.
Mentions: VFAs concentrations were determined during the whole operation period and only acetate and propionate were detected in the liquid phase. The production and consumption of these two kinds of VFAs were shown in Fig. 6. Simple organics could be rapidly fermented to volatile acids under anaerobic conditions18, thus, both the acetate and propionate were produced within 12 hours with glucose served as substrates. With manganese addition, significant differences in acetate concentrations were observed in the present study (Fig. 6a). The acetate concentrations of control fluctuated between 450 mg/L and 600 mg/L and the small amount consumption of acetate, one of the substrates for methanogens, was consistent with the CH4 production during the research (Fig. 1a). However, with 2 g/L manganese added, the acetate concentration dropped to 0 mg/L at 84 h. As a result, the CH4 production rate increased distinctly during this period (Fig. 1a). The increase in the manganese concentration to 4 g/L resulted in a reduction in the acetate at 12 h, which was only about 250 mg/L, just 45.5% of the control. Besides, it was similar with the former that the acetate concentration decreased to 0 mg/L at 84 h. The acetate concentration with 8 g/L manganese added changed intricately. Though a reduction in acetate generation was also found at 12 h, the concentration increased suddenly at 60 h after a period of stationary phase, and then it declined slowly. It was assumed that some inhibitory effects on the methanogenesis occurred in the digestion system.

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.