TY - JOUR
T1 - Effect of specific cathode surface area on biofouling in an anaerobic electrochemical membrane bioreactor: Novel insights using high-speed video camera
AU - Sapireddy, Veerraghavulu
AU - Ragab, Alaa I.
AU - Katuri, Krishna
AU - Yu, Yuanlie
AU - Lai, Zhiping
AU - Li, Erqiang
AU - Thoroddsen, Sigurdur T
AU - Saikaly, Pascal
N1 - KAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): FCC/1/1971-33-01
Acknowledgements: This work was supported by Center Competitive Funding Program (FCC/1/1971-33-01) to P.E.S. from King Abdullah University of Science and Technology (KAUST). The authors would like to thank Dr. Srikanth Pedireddy at the Water Desalination and Reuse Center (WDRC) for generating the schematic figure (Fig. S3) of the AnEMBR.
PY - 2019/2/5
Y1 - 2019/2/5
N2 - The effect of specific cathode surface area (SCSA; 2, 4 and 8 m2/m3) on biogas production and biofouling control was investigated in anaerobic electrochemical membrane bioreactors (AnEMBRs). Nickel-based hollow fibers were used as both a cathode for hydrogen evolution and a membrane for the filtration of treated water. Varying the SCSA was found to influence the current density, biogas quantity and composition, and trans-membrane pressure (TMP). In situ gas generation was monitored using a high-speed camera; where the 8 m2/m3 AnEMBRs were found to mainly evolve smaller sized bubbles (45–114 µm) compared to the 2 and 4 m2/m3 AnEMBRs. This correlated with the lowest TMP (0.37 bars) compared to the other reactors (4 m2/m3, 0.76 bars; 2 m2/m3, 1.18 bars). The cathodic microbial community varied with SCSA, with Acetobacterium dominating at a relative abundance that reached 62% (4 m2/m3), while hydrogenotrophic methanogens (represented by Methanocorpusculum) comprised up to 2.5% of the total community. This community variability apparently influenced both the hydrogen (QH2) and methane (QCH4) production rates, reaching a maximum QH2 of 0.416 m3/m3/day (SCSA 8 m2/m3). Overall, this study discloses the cumulative effect of QH2, QCH4, bubble distribution and frequency on biofouling with SCSA variation in AnEMBRs, demonstrating that with higher SCSA the in situ gas scouring effect is more pronounced leading to a lower fouling propensity.
AB - The effect of specific cathode surface area (SCSA; 2, 4 and 8 m2/m3) on biogas production and biofouling control was investigated in anaerobic electrochemical membrane bioreactors (AnEMBRs). Nickel-based hollow fibers were used as both a cathode for hydrogen evolution and a membrane for the filtration of treated water. Varying the SCSA was found to influence the current density, biogas quantity and composition, and trans-membrane pressure (TMP). In situ gas generation was monitored using a high-speed camera; where the 8 m2/m3 AnEMBRs were found to mainly evolve smaller sized bubbles (45–114 µm) compared to the 2 and 4 m2/m3 AnEMBRs. This correlated with the lowest TMP (0.37 bars) compared to the other reactors (4 m2/m3, 0.76 bars; 2 m2/m3, 1.18 bars). The cathodic microbial community varied with SCSA, with Acetobacterium dominating at a relative abundance that reached 62% (4 m2/m3), while hydrogenotrophic methanogens (represented by Methanocorpusculum) comprised up to 2.5% of the total community. This community variability apparently influenced both the hydrogen (QH2) and methane (QCH4) production rates, reaching a maximum QH2 of 0.416 m3/m3/day (SCSA 8 m2/m3). Overall, this study discloses the cumulative effect of QH2, QCH4, bubble distribution and frequency on biofouling with SCSA variation in AnEMBRs, demonstrating that with higher SCSA the in situ gas scouring effect is more pronounced leading to a lower fouling propensity.
UR - http://hdl.handle.net/10754/631168
UR - https://www.sciencedirect.com/science/article/pii/S0376738818323779
UR - http://www.scopus.com/inward/record.url?scp=85061303345&partnerID=8YFLogxK
U2 - 10.1016/j.memsci.2019.02.007
DO - 10.1016/j.memsci.2019.02.007
M3 - Article
SN - 0376-7388
VL - 577
SP - 176
EP - 183
JO - Journal of Membrane Science
JF - Journal of Membrane Science
ER -