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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.


CH4(a) and CO2 (b) production during the anaerobic digestion with different dosages of elemental manganese addition. Error bars represent standard deviations of triplicate tests.
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f1: CH4(a) and CO2 (b) production during the anaerobic digestion with different dosages of elemental manganese addition. Error bars represent standard deviations of triplicate tests.

Mentions: During the batch experiment, glucose was utilized as organic carbon source, which could be fermented to VFAs rapidly. Therefore, the methanogenesis process was proved to be the rate-determining step20. Figure 1a described the methane accumulation in the head space within the whole operation of 120 h. The methane production rate of the control was slow before 48 h due to the accumulation of VFAs, exactly, the propionic acid, which could inhibit the activity of methanogenic archaea22. Then, after a period of adaptation, the methane production rate increased since 60 h and it was calculated as about 6.2 ± 0.1 mM/gVSS/h during the whole operation period. In order to investigate the effect of elemental manganese on the methanogenesis, 2 g/L, 4 g/L and 8 g/L of manganese powder were added into the anaerobic systems respectively. With 2 g/L manganese powder addition, the methane accumulation before 48 h slightly increased, and then a sharp rise was observed after 60 h with a final methane yield of 2.44 ± 0.15 M/gVSS and a production rate of 21.5 ± 1.5 mM/gVSS/h, which were about 2.7-fold and 3.5-fold higher than those of the control. An interesting result was obtained with 4 g/L and 8 g/L manganese powder additions that the methane producing process occurred rapidly without adaptation, compared with the other two experimental assays. In addition, both the methane yields and the production rates were significantly enhanced with final methane yields of 2.99 ± 0.37 and 2.64 ± 0.26 M/gVSS and production rates of 27.2 ± 2.2 and 21.5 ± 0.3 mM/gVSS/h, respectively. However, the increase in elemental manganese dosage to 8 g/L did not cause the highest methane yield and producing rate, which indicated that 4 g/L might be a more appropriate addition concentration for methanogenesis in the present study.


Methanogenesis from wastewater stimulated by addition of elemental manganese.

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

CH4(a) and CO2 (b) production during the anaerobic digestion 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

f1: CH4(a) and CO2 (b) production during the anaerobic digestion with different dosages of elemental manganese addition. Error bars represent standard deviations of triplicate tests.
Mentions: During the batch experiment, glucose was utilized as organic carbon source, which could be fermented to VFAs rapidly. Therefore, the methanogenesis process was proved to be the rate-determining step20. Figure 1a described the methane accumulation in the head space within the whole operation of 120 h. The methane production rate of the control was slow before 48 h due to the accumulation of VFAs, exactly, the propionic acid, which could inhibit the activity of methanogenic archaea22. Then, after a period of adaptation, the methane production rate increased since 60 h and it was calculated as about 6.2 ± 0.1 mM/gVSS/h during the whole operation period. In order to investigate the effect of elemental manganese on the methanogenesis, 2 g/L, 4 g/L and 8 g/L of manganese powder were added into the anaerobic systems respectively. With 2 g/L manganese powder addition, the methane accumulation before 48 h slightly increased, and then a sharp rise was observed after 60 h with a final methane yield of 2.44 ± 0.15 M/gVSS and a production rate of 21.5 ± 1.5 mM/gVSS/h, which were about 2.7-fold and 3.5-fold higher than those of the control. An interesting result was obtained with 4 g/L and 8 g/L manganese powder additions that the methane producing process occurred rapidly without adaptation, compared with the other two experimental assays. In addition, both the methane yields and the production rates were significantly enhanced with final methane yields of 2.99 ± 0.37 and 2.64 ± 0.26 M/gVSS and production rates of 27.2 ± 2.2 and 21.5 ± 0.3 mM/gVSS/h, respectively. However, the increase in elemental manganese dosage to 8 g/L did not cause the highest methane yield and producing rate, which indicated that 4 g/L might be a more appropriate addition concentration for methanogenesis in the present study.

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.