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Effect of N/S ratio on anoxic sulfide oxidizing bioreactors

Research output: Other conference contributionPaper, poster or abstractScientific

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Effect of N/S ratio on anoxic sulfide oxidizing bioreactors. / Khanongnuch, Ramita; Di Capua, Francesco; Lakaniemi, Aino-Maija; R. Rene, Eldon; Lens, Piet N. L.

2017. Paper presented at Biotechniques 2017, La Coruña, Spain.

Research output: Other conference contributionPaper, poster or abstractScientific

Harvard

Khanongnuch, R, Di Capua, F, Lakaniemi, A-M, R. Rene, E & Lens, PNL 2017, 'Effect of N/S ratio on anoxic sulfide oxidizing bioreactors' Paper presented at Biotechniques 2017, La Coruña, Spain, 19/07/17 - 22/07/17, .

APA

Khanongnuch, R., Di Capua, F., Lakaniemi, A-M., R. Rene, E., & Lens, P. N. L. (2017). Effect of N/S ratio on anoxic sulfide oxidizing bioreactors. Paper presented at Biotechniques 2017, La Coruña, Spain.

Vancouver

Khanongnuch R, Di Capua F, Lakaniemi A-M, R. Rene E, Lens PNL. Effect of N/S ratio on anoxic sulfide oxidizing bioreactors. 2017. Paper presented at Biotechniques 2017, La Coruña, Spain.

Author

Khanongnuch, Ramita ; Di Capua, Francesco ; Lakaniemi, Aino-Maija ; R. Rene, Eldon ; Lens, Piet N. L. / Effect of N/S ratio on anoxic sulfide oxidizing bioreactors. Paper presented at Biotechniques 2017, La Coruña, Spain.

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@conference{7de5492af8ad444f9c96581932955a55,
title = "Effect of N/S ratio on anoxic sulfide oxidizing bioreactors",
abstract = "Hydrogen sulfide (H2S) removal from biogas using anoxic bioprocesses are economic and efficient compared to physico-chemical H2S removal or other biogas upgrading technologies. Most of these biotechnologies have used nitrate-reducing, sulfide-oxidizing bacteria (NR-SOB) as the dominant microorganism for H2S removal. Anoxic sulfide removal technologies have been widely applied for both liquid and gaseous pollutants, particularly for biogas clean-up, because it is more practically applicable than the conventional aerobic systems in terms of ease of use and operational costs (Almenglo et al. 2016; Fern{\'a}ndez et al. 2014; Soreanu et al., 2008). In this study, the performance of an attached growth bioreactor, i.e. a fluidized bed reactor (FBR) and a combined attached and suspended growth bioreactor, i.e. a moving bed bioreactor (MBBR), were tested under different operating conditions and the bioreactors were compared for their ability to perform sulfur oxidation coupled to autotrophic denitrification.In anoxic sulfide-oxidizing reactors, a crucial factor is the nitrogen/sulfur (N/S) ratio, which affects the metabolism of nitrate-reducing, sulfide-oxidizing bacteria (NR-SOB) and the ratio of the end products of sulfide oxidation such as elemental sulfur and sulfate. Thus, the objective of this study was to evaluate the effect of the N/S ratio on the thiosulfate removal efficiency in two different anoxic biofilm bioreactors, i.e. a MBBR and a FBR, as shown in Figure 1. Both the lab-scale MBBR and FBR were operated for 250 days, at room temperature (~20 ºC) and at a feed pH of 7.0 ± 0.2. The dissolved oxygen (DO) concentrations in the MBBR and FBR were 0.51 ± 0.09 and 0.26 ± 0.06 mg L-1, respectively. The FBR used in this study was previously used for thiosulfate-driven denitrification (Di Capua et al. 2017). The MBBR was inoculated by using the biomass obtained from that FBR containing Thiobacillus denitrificans as the dominant microorganism. The performance of the MBBR and FBR were evaluated under three different N/S ratios (0.5, 0.3 and 0.1). Thiosulfate was used as a substrate for sulfide-oxidizing bacteria at a constant concentration of 200 mg S-S2O32- L-1, whereas the concentration of the electron acceptor, nitrate, was decreased stepwise from 40 to 10 mg N-NO3- L-1. The performances of the MBBR and FBR can be compared in Table 1. The removal efficiency of thiosulfate was > 98{\%} and nitrate was completely consumed during the operational time in both bioreactors at N/S ratio of 0.5. Under the nitrate-limiting conditions tested, i.e. N/S ratio of 0.3 and 0.1, the thiosulfate removal efficiencies in the MBBR (83.4 and 37.8{\%}) were higher than those observed in the FBR (77.8 and 26.1{\%}), resulting in a higher sulfate production.The higher DO concentrations observed in the MBBR compared to the FBR likely played a role in enhancing thiosulfate oxidation due to T. denitrificans, a dominant microorganism in the inoculum, being a facultative anaerobe which enables to use oxygen as alternative e- acceptor to oxidize the thiosulfate. Additionally, it was probably because of the different bioreactor configuration and mixing conditions. Conclusions The MBBR and FBR can be operated at room temperature (~20 ºC) for achieving high removal efficiencies of thiosulfate (> 98{\%}), under autotrophic denitrification conditions, at a HRT of 5 h, feed pH of 7 and a N/S ratio of 0.5. However, the MBBR resulted in higher thiosulfate oxidation rates than the FBR after the nitrate-limiting conditions were applied. The reactor performance at a N/S ratio of 0.1 and the evaluation of the microbial community composition at different N/S ratios require further investigation.",
keywords = "Biological desulfurization, Sulfide oxidizing bacteria (SOB), Autotrophic denitrification, Moving bed biofilm reactor (MBBR), Fluidized bed biofilm reactor (FBR)",
author = "Ramita Khanongnuch and {Di Capua}, Francesco and Aino-Maija Lakaniemi and {R. Rene}, Eldon and Lens, {Piet N. L.}",
year = "2017",
month = "7",
day = "19",
language = "English",
note = "Biotechniques 2017 : International Conference on Biotechniques for Air Pollution Control and Bioenergy ; Conference date: 19-07-2017 Through 22-07-2017",
url = "http://bioengingroup.es/biotechniques2017/",

}

RIS (suitable for import to EndNote) - Download

TY - CONF

T1 - Effect of N/S ratio on anoxic sulfide oxidizing bioreactors

AU - Khanongnuch, Ramita

AU - Di Capua, Francesco

AU - Lakaniemi, Aino-Maija

AU - R. Rene, Eldon

AU - Lens, Piet N. L.

PY - 2017/7/19

Y1 - 2017/7/19

N2 - Hydrogen sulfide (H2S) removal from biogas using anoxic bioprocesses are economic and efficient compared to physico-chemical H2S removal or other biogas upgrading technologies. Most of these biotechnologies have used nitrate-reducing, sulfide-oxidizing bacteria (NR-SOB) as the dominant microorganism for H2S removal. Anoxic sulfide removal technologies have been widely applied for both liquid and gaseous pollutants, particularly for biogas clean-up, because it is more practically applicable than the conventional aerobic systems in terms of ease of use and operational costs (Almenglo et al. 2016; Fernández et al. 2014; Soreanu et al., 2008). In this study, the performance of an attached growth bioreactor, i.e. a fluidized bed reactor (FBR) and a combined attached and suspended growth bioreactor, i.e. a moving bed bioreactor (MBBR), were tested under different operating conditions and the bioreactors were compared for their ability to perform sulfur oxidation coupled to autotrophic denitrification.In anoxic sulfide-oxidizing reactors, a crucial factor is the nitrogen/sulfur (N/S) ratio, which affects the metabolism of nitrate-reducing, sulfide-oxidizing bacteria (NR-SOB) and the ratio of the end products of sulfide oxidation such as elemental sulfur and sulfate. Thus, the objective of this study was to evaluate the effect of the N/S ratio on the thiosulfate removal efficiency in two different anoxic biofilm bioreactors, i.e. a MBBR and a FBR, as shown in Figure 1. Both the lab-scale MBBR and FBR were operated for 250 days, at room temperature (~20 ºC) and at a feed pH of 7.0 ± 0.2. The dissolved oxygen (DO) concentrations in the MBBR and FBR were 0.51 ± 0.09 and 0.26 ± 0.06 mg L-1, respectively. The FBR used in this study was previously used for thiosulfate-driven denitrification (Di Capua et al. 2017). The MBBR was inoculated by using the biomass obtained from that FBR containing Thiobacillus denitrificans as the dominant microorganism. The performance of the MBBR and FBR were evaluated under three different N/S ratios (0.5, 0.3 and 0.1). Thiosulfate was used as a substrate for sulfide-oxidizing bacteria at a constant concentration of 200 mg S-S2O32- L-1, whereas the concentration of the electron acceptor, nitrate, was decreased stepwise from 40 to 10 mg N-NO3- L-1. The performances of the MBBR and FBR can be compared in Table 1. The removal efficiency of thiosulfate was > 98% and nitrate was completely consumed during the operational time in both bioreactors at N/S ratio of 0.5. Under the nitrate-limiting conditions tested, i.e. N/S ratio of 0.3 and 0.1, the thiosulfate removal efficiencies in the MBBR (83.4 and 37.8%) were higher than those observed in the FBR (77.8 and 26.1%), resulting in a higher sulfate production.The higher DO concentrations observed in the MBBR compared to the FBR likely played a role in enhancing thiosulfate oxidation due to T. denitrificans, a dominant microorganism in the inoculum, being a facultative anaerobe which enables to use oxygen as alternative e- acceptor to oxidize the thiosulfate. Additionally, it was probably because of the different bioreactor configuration and mixing conditions. Conclusions The MBBR and FBR can be operated at room temperature (~20 ºC) for achieving high removal efficiencies of thiosulfate (> 98%), under autotrophic denitrification conditions, at a HRT of 5 h, feed pH of 7 and a N/S ratio of 0.5. However, the MBBR resulted in higher thiosulfate oxidation rates than the FBR after the nitrate-limiting conditions were applied. The reactor performance at a N/S ratio of 0.1 and the evaluation of the microbial community composition at different N/S ratios require further investigation.

AB - Hydrogen sulfide (H2S) removal from biogas using anoxic bioprocesses are economic and efficient compared to physico-chemical H2S removal or other biogas upgrading technologies. Most of these biotechnologies have used nitrate-reducing, sulfide-oxidizing bacteria (NR-SOB) as the dominant microorganism for H2S removal. Anoxic sulfide removal technologies have been widely applied for both liquid and gaseous pollutants, particularly for biogas clean-up, because it is more practically applicable than the conventional aerobic systems in terms of ease of use and operational costs (Almenglo et al. 2016; Fernández et al. 2014; Soreanu et al., 2008). In this study, the performance of an attached growth bioreactor, i.e. a fluidized bed reactor (FBR) and a combined attached and suspended growth bioreactor, i.e. a moving bed bioreactor (MBBR), were tested under different operating conditions and the bioreactors were compared for their ability to perform sulfur oxidation coupled to autotrophic denitrification.In anoxic sulfide-oxidizing reactors, a crucial factor is the nitrogen/sulfur (N/S) ratio, which affects the metabolism of nitrate-reducing, sulfide-oxidizing bacteria (NR-SOB) and the ratio of the end products of sulfide oxidation such as elemental sulfur and sulfate. Thus, the objective of this study was to evaluate the effect of the N/S ratio on the thiosulfate removal efficiency in two different anoxic biofilm bioreactors, i.e. a MBBR and a FBR, as shown in Figure 1. Both the lab-scale MBBR and FBR were operated for 250 days, at room temperature (~20 ºC) and at a feed pH of 7.0 ± 0.2. The dissolved oxygen (DO) concentrations in the MBBR and FBR were 0.51 ± 0.09 and 0.26 ± 0.06 mg L-1, respectively. The FBR used in this study was previously used for thiosulfate-driven denitrification (Di Capua et al. 2017). The MBBR was inoculated by using the biomass obtained from that FBR containing Thiobacillus denitrificans as the dominant microorganism. The performance of the MBBR and FBR were evaluated under three different N/S ratios (0.5, 0.3 and 0.1). Thiosulfate was used as a substrate for sulfide-oxidizing bacteria at a constant concentration of 200 mg S-S2O32- L-1, whereas the concentration of the electron acceptor, nitrate, was decreased stepwise from 40 to 10 mg N-NO3- L-1. The performances of the MBBR and FBR can be compared in Table 1. The removal efficiency of thiosulfate was > 98% and nitrate was completely consumed during the operational time in both bioreactors at N/S ratio of 0.5. Under the nitrate-limiting conditions tested, i.e. N/S ratio of 0.3 and 0.1, the thiosulfate removal efficiencies in the MBBR (83.4 and 37.8%) were higher than those observed in the FBR (77.8 and 26.1%), resulting in a higher sulfate production.The higher DO concentrations observed in the MBBR compared to the FBR likely played a role in enhancing thiosulfate oxidation due to T. denitrificans, a dominant microorganism in the inoculum, being a facultative anaerobe which enables to use oxygen as alternative e- acceptor to oxidize the thiosulfate. Additionally, it was probably because of the different bioreactor configuration and mixing conditions. Conclusions The MBBR and FBR can be operated at room temperature (~20 ºC) for achieving high removal efficiencies of thiosulfate (> 98%), under autotrophic denitrification conditions, at a HRT of 5 h, feed pH of 7 and a N/S ratio of 0.5. However, the MBBR resulted in higher thiosulfate oxidation rates than the FBR after the nitrate-limiting conditions were applied. The reactor performance at a N/S ratio of 0.1 and the evaluation of the microbial community composition at different N/S ratios require further investigation.

KW - Biological desulfurization

KW - Sulfide oxidizing bacteria (SOB)

KW - Autotrophic denitrification

KW - Moving bed biofilm reactor (MBBR)

KW - Fluidized bed biofilm reactor (FBR)

M3 - Paper, poster or abstract

ER -