Hydrogen-based, hollow-fiber membrane biofilm reactor for reduction of perchlorate and other oxidized contaminants

2004 ◽  
Vol 49 (11-12) ◽  
pp. 223-230 ◽  
Author(s):  
R. Nerenberg ◽  
B.E. Rittmann
Keyword(s):  
Drinking Water ◽  
Electron Donor ◽  
Hollow Fiber ◽  
Hollow Fiber Membrane ◽  
Chlorinated Solvents ◽  
Drinking Water Treatment ◽  
Primary Electron ◽  
Biofilm Reactor ◽  
Fiber Membrane ◽  
Membrane Biofilm Reactor

Many oxidized pollutants, such as nitrate, perchlorate, bromate, and chlorinated solvents, can be microbially reduced to less toxic or less soluble forms. For drinking water treatment, an electron donor must be added. Hydrogen is an ideal electron donor, as it is non-toxic, inexpensive, and sparsely soluble. We tested a hydrogen-based, hollow-fiber membrane biofilm reactor (MBfR) for reduction of perchlorate, bromate, chlorate, chlorite, chromate, selenate, selenite, and dichloromethane. The influent included 5 mg/L nitrate or 8 mg/L oxygen as a primary electron accepting substrate, plus 1 mg/L of the contaminant. The mixed-culture reactor was operated at a pH of 7 and with a 25 minute hydraulic detention time. High recirculation rates provided completely mixed conditions. The objective was to screen for the reduction of each contaminant. The tests were short-term, without allowing time for the reactor to adapt to the contaminants. Nitrate and oxygen were reduced by over 99 percent for all tests. Removals for the contaminants ranged from a minimum of 29% for chlorate to over 95% for bromate. Results show that the tested contaminants can be removed as secondary substrates in an MBfR, and that the MBfR may be suitable for treating these and other oxidized contaminants in drinking water.

Evidence of specialized bromate-reducing bacteria in a hollow fiber membrane biofilm reactor

2009 ◽  
Vol 59 (10) ◽  
pp. 1969-1974 ◽  
Author(s):  
K. J. Martin ◽  
L. S. Downing ◽  
R. Nerenberg
Keyword(s):  
Hollow Fiber ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Selective Pressure ◽  
Hollow Fiber Membrane ◽  
Primary Electron ◽  
Biofilm Reactor ◽  
Fiber Membrane ◽  
Membrane Biofilm Reactor ◽  
Reducing Bacteria ◽  
Bromate Reduction

Bromate is a carcinogenic disinfection by-product formed from bromide during ozonation or advanced oxidation. We previously observed bromate reduction in a hydrogen-based, denitrifying hollow fiber membrane biofilm reactor (MBfR). In this research, we investigated the potential existence of specialized bromate-reducing bacteria. Using denaturing gradient gel electrophoresis (DGGE), we compared the microbial ecology of two denitrifying MBfRs, one amended with nitrate as the electron acceptor and the other with nitrate plus bromate. The DGGE results showed that bromate exerted a selective pressure for a putative, specialized bromate-reducing bacterium, which developed a strong presence only in the reactor with bromate. To gain further insight into the capabilities of specialized, bromate-reducing bacteria, we explored bromate reduction in a control MBfR without any primary electron acceptors. A grown biofilm in the control MBfR reduced bromate without previous exposure, but the rate of reduction decreased over time, especially after perturbations resulting in biomass loss. The decrease in bromate reduction may have been the result of the toxic effects of bromate. We also used batch tests of the perchlorate-reducing pure culture, Dechloromonas sp. PC1 to test bromate reduction and growth. Bromate was reduced without measurable growth. Based on these results, we speculate bromate's selective pressure for the putative, specialized BRB observed in the DGGE was not growth related, but possibly based on resistance to bromate toxicity.

Study on Membrane Fouling of a Hydrogen-Based Membrane Biofilm Reactor Treating Nitrate-Contaminated Drinking Water

2013 ◽  
Vol 361-363 ◽  
pp. 814-817
Author(s):  
Gang Li ◽  
Jun Yu ◽  
Yan Hao Zhang ◽  
Lei Gao ◽  
Hua Zhang
Keyword(s):  
Drinking Water ◽  
Nitrogen Removal ◽  
Hollow Fiber ◽  
Membrane Fouling ◽  
Hollow Fiber Membrane ◽  
Biofilm Reactor ◽  
Fiber Membrane ◽  
Membrane Biofilm Reactor ◽  
Contaminated Drinking Water ◽  
Total Nitrogen Removal

A hollow fiber membrane biofilm reactor (MBfR) using Polyethylene (PE) membranes was investigated for denitrification in nitrate-contimanitated drinking water. The reactor was operated over 85 days with influent nitrate loading increasing gradually. The result showed that maximum of nitrate denitrification rate achieved was 3.84 g NO3ˉ-N/m3/d (1.36 g NO3ˉ-N/m2/d) and the total nitrogen removal was more than 96%. The results also showed that the membrane pollution was mainly caused by the mineral sedimentation and EPS.

Evidence of specialized bromate-reducing bacteria in a hollow fiber membrane biofilm reactor

2008 ◽  
Vol 8 (4) ◽  
pp. 473-479
Author(s):  
K. J. Martin ◽  
L. S. Downing ◽  
R. Nerenberg
Keyword(s):  
Hollow Fiber ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Selective Pressure ◽  
Hollow Fiber Membrane ◽  
Primary Electron ◽  
Biofilm Reactor ◽  
Fiber Membrane ◽  
Membrane Biofilm Reactor ◽  
Reducing Bacteria ◽  
Bromate Reduction

Bromate is a carcinogenic disinfection by-product formed from bromide during ozonation or advanced oxidation of drinking water. We previously observed bromate reduction in a hydrogen-based, denitrifying hollow fiber membrane biofilm reactor (MBfR). In this research, we investigated the potential existence of specialized bromate-reducing bacteria. Using denaturing gradient gel electrophoresis (DGGE), we compared the microbial ecology of two denitrifying MBfRs, one amended with nitrate as the electron acceptor and the other with nitrate plus bromate. The DGGE results showed that bromate exerted a selective pressure for a putative, specialized bromate-reducing bacterium, which developed a strong presence only in the reactor with bromate. To gain further insight into the capabilities of specialized, bromate-reducing bacteria, we explored bromate reduction in a control MBfR without any primary electron acceptors. A grown biofilm in the control MBfR reduced bromate without previous exposure, but the rate of reduction decreased over time, especially after perturbations resulting in biomass loss. The decrease in bromate reduction may have been the result of the toxic effects of bromate. We also used batch tests of the perchlorate-reducing pure culture, Dechloromonas sp. PC1 to test bromate reduction and growth. Bromate was reduced without measurable growth. Based on these results, we speculate bromate's selective pressure for the putative, specialized BRB observed in the DGGE was not growth related, but possibly based on resistance to bromate toxicity.

Perchlorate as a secondary substrate in a denitrifying, hollow-fiber membrane biofilm reactor

2002 ◽  
Vol 2 (2) ◽  
pp. 259-265 ◽  
Author(s):  
R. Nerenberg ◽  
B.E. Rittmann
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Hollow Fiber ◽  
Hollow Fiber Membrane ◽  
Tap Water ◽  
Drinking Water Treatment ◽  
Biofilm Reactor ◽  
Fiber Membrane ◽  
Biological Reduction ◽  
Treatment Processes

In recent years, several oxyanions have emerged as drinking water micropollutants, including arsenate, selenate, bromate, and, most recently, perchlorate (ClO4-). Conventional water treatment processes typically are ineffective in removing these compounds, and advanced treatment processes are expensive. Biological reduction may provide a suitable treatment alternative, since these compounds can serve as electron acceptors. Other acceptors, such as nitrate (NO3-), must act as a primary electron acceptor. We tested our denitrifying, autotrophic, hydrogen-oxidizing hollow-fiber membrane for ClO4- reduction. The reactor is highly suited to drinking water treatment, as hydrogen (H2) is inexpensive, non-toxic, and does not leave residuals that can cause regrowth. When 1 to 2 mg/L ClO4- was supplied to reactor, which was at steady-state with 5 mgN/L NO3- but unacclimated to ClO4-, ClO4- removals increased from 40 to 99% over three weeks. Removals to 4 μg/L were also achieved in a natural groundwater having 6 to 100 μg/L ClO4-. Tests with variable NO3- and H2 showed that ClO4- reduction requires less than 30 μgN/L NO3- and at least 300-μg/L effluent H2. Therefore, partial denitrification is probably not consistent with excellent ClO4- removal. Mineral medium produced a gradual loss of ClO4--reducing bacteria, but they were re-enriched when tap water replaced minimal medium.

Hydrogen-based hollow-fiber membrane biofilm reactor (MBfR) for removing oxidized contaminants

2004 ◽  
Vol 4 (1) ◽  
pp. 127-133 ◽  
Author(s):  
B.E. Rittmann ◽  
R. Nerenberg ◽  
K.-C. Lee ◽  
I. Najm ◽  
T.E. Gillogly ◽  
...  
Keyword(s):  
Hollow Fiber ◽  
Hydrogen Pressure ◽  
Hollow Fiber Membrane ◽  
Nitrate Removal ◽  
Critical Role ◽  
Chlorinated Solvents ◽  
Biofilm Reactor ◽  
Fiber Membrane ◽  
Perchlorate Reduction ◽  
Membrane Biofilm Reactor

Research with a laboratory prototype and at the pilot scale documents that the hydrogen-based hollow-fiber Membrane-Biofilm Reactor (MBfR) is technically and economically feasible for reduction of nitrate and perchlorate. In the MBfR, H2 gas diffuses through the wall of a composite membrane, and an autotrophic biofilm naturally develops on the outside of the membrane, where the bacteria's electron acceptor is an oxidized contaminant (e.g., NO3− or ClO4−) supplied from the water. The hydrogen pressure to the hollow fibers is a key control parameter that can be adjusted rapidly and easily. For denitrification, partial nitrate removal often is acceptable, and the hydrogen pressure can be low to minimize the costs of H2 supply and the concentration of H2 in the effluent. When perchlorate must be reduced, full nitrate removal is essential, since NO3−-N above about 0.2 mg/L slows perchlorate reduction. Perchlorate reduction is sensitive to the hydrogen pressure, which underscores the critical role of H2 pressure for controlling process performance. Given that H2-oxidizing microorganisms have the potential to reduce many oxidized contaminants, we hypothesize that and are beginning to test how well the MBfR reduces bromate, selenate, chlorinated solvents, and other oxidized contaminants.

Bioreduction of para-chloronitrobenzene in a hydrogen-based hollow-fiber membrane biofilm reactor: effects of nitrate and sulfate

2013 ◽  
Vol 25 (2) ◽  
pp. 205-215 ◽  
Author(s):  
Haixiang Li ◽  
Zhiqiang Zhang ◽  
Xiaoyin Xu ◽  
Jun Liang ◽  
Siqing Xia
Keyword(s):  
Hollow Fiber ◽  
Hollow Fiber Membrane ◽  
Biofilm Reactor ◽  
Fiber Membrane ◽  
Membrane Biofilm Reactor
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