Performance and microbial ecology of the hybrid membrane biofilm process for concurrent nitrification and denitrification of wastewater

2007 ◽  
Vol 55 (8-9) ◽  
pp. 355-362 ◽  
Author(s):  
L.S. Downing ◽  
R. Nerenberg
Keyword(s):  
Clone Library ◽  
Heterotrophic Bacteria ◽  
Ammonia Concentration ◽  
Hollow Fibre ◽  
Hybrid Membrane ◽  
Nitrifying Bacteria ◽  
Bulk Liquid ◽  
Biofilm Thickness ◽  
Nitrification And Denitrification ◽  
Biofilm Process

We report on a novel process for total nitrogen (TN) removal, the hybrid membrane biofilm process (HMBP). The HMBP uses air-supplying hollow-fibre membranes inside an activated sludge tank, with suppressed aeration, to allow concurrent nitrification and denitrification. We hypothesised that a nitrifying biofilm would form on the membranes, and that the low bulk-liquid BOD concentrations would encourage heterotrophic denitrifying bacteria to grow in suspension. A nitrifying biofilm was initially established by supplying an influent ammonia concentration of 20 mgN/L. Subsequently, 120 mg/L acetate was added to the influent as BOD. With a bulk-liquid SRT of only 5 days, nitrification rates were 0.85 gN/m2 per day and the TN removal reached 75%. The biofilm thickness was approximately 500 μm. We used DGGE to obtain a microbial community fingerprint of suspended and attached growth, and prepared a clone library. The DGGE results, along with the clone library and operating data, suggest that nitrifying bacteria were primarily attached to the membranes, while heterotrophic bacteria were predominant in the bulk liquid. Our results demonstrate that the HMBP is effective for TN removal, achieving high levels of nitrification with a low bulk-liquid SRT and concurrently denitrifying with BOD as the sole electron donor.

Sustainable nitrogen removal from wastewater with the hybrid membrane biofilm process (HMBP): bench-scale studies

2008 ◽  
Vol 58 (9) ◽  
pp. 1715-1720 ◽  
Author(s):  
Leon S. Downing ◽  
Robert Nerenberg
Keyword(s):  
Nitrogen Removal ◽  
Heterotrophic Bacteria ◽  
Outer Edge ◽  
Hybrid Membrane ◽  
Nitrogen Loading ◽  
Bulk Liquid ◽  
Dominant Form ◽  
Bench Scale ◽  
Conventional Activated Sludge ◽  
Biofilm Process

The hybrid membrane biofilm process (HMBP) is a novel approach to achieving total nitrogen removal from wastewater. It incorporates air-supplying, hollow-fiber membranes into a conventional activated sludge tank, where bulk aeration is suppressed. A nitrifying biofilm grows on the membranes and exports nitrite and nitrate to the anoxic bulk liquid, where suspended heterotrophic bacteria denitrify using influent BOD as an electron donor. Bench scale tests were used to assess the performance of the HMBP for a variety of nitrogen and BOD loading rates. For a nitrogen loading of 1.6 gN m−2, the nitrification flux remained at approximately 1.0 gN m−2 d−1 for BOD loadings ranging from 4 to 17 gBOD m−2 d−1 day−1. Full denitrification was achieved when sufficient BOD was available in the influent. Microsensor measurements indicated nitrite was the dominant form of oxidized nitrogen produced by the biofilm, showing that shortcut nitrogen removal was taking place. Fluorescence in-situ hybridization (FISH) tests on the biofilm revealed a unique stratification, with three distinct regions: AOB and NOB near the membrane, strictly AOB at intermediate depths, and AOB and heterotrophs at the outer edge of the biofilm.

Kinetic analysis of nitrifying biofilm growing on the rotating membrane disk

2001 ◽  
Vol 1 (4) ◽  
pp. 111-118
Author(s):  
K. Kimura ◽  
Y. Watanabe ◽  
S. Okabe ◽  
H. Satoh
Keyword(s):  
Membrane Filtration ◽  
Consumption Rate ◽  
Ammonia Concentration ◽  
Ammonia Nitrogen ◽  
Nitrifying Bacteria ◽  
Conventional Model ◽  
Biofilm Thickness ◽  
Term Operation ◽  
First Order ◽  
Calculated Profile

The authors have proposed a novel water treatment process in which nitrifying bacteria are fixed on the surface of rotating membrane disks. This biofilm-membrane process can perform strict solid-liquid separation and oxidation of ammonia nitrogen simultaneously. In this research, applicability of the conventional biofilm model (assuming the biofilm structure to be flat, homogeneous and continuous) to analysis of the biofilm developing in the proposed process was examined. A long-term operation for culturing the active nitrifying biofilm was carried out prior to kinetic investigation. By cryosectioning of the biofilm and image analysis, the thickness of the biofilm was determined to be 87 μm. From this biofilm thickness and the result of the batch ammonia consumption test, the intrinsic zero-order ammonia consumption rate of the biofilm was estimated precisely to be 930 g/m3/h. Using these parameters, the ammonia concentration profile in the biofilm was calculated by the conventional model, and the applicability of the model was examined by comparing the calculated profile with the ones measured with a microelectrode. The calculated profile was very close to the measured ones, which indicated feasibility of the conventional model to the analysis of the biofilm grown in the proposed process. The studied biofilm actually had a simple, i.e. flat, homogeneous and continuous, structure due to membrane filtration. This was the reason why the conventional model could still be employed. In the analysis of the data dealing with low concentrations of ammonia, however, first-order kinetics should be used. The first-order ammonia consumption rate constant of the studied biofilm was estimated to be 808 h-1.

Distribution of nitrifying bacteria in a shallow stream

1997 ◽  
Vol 36 (8-9) ◽  
pp. 161-166 ◽  
Author(s):  
Ivana Jancarkova ◽  
Tove A. Larsen ◽  
Willi Gujer
Keyword(s):  
Field Experiments ◽  
Heterotrophic Bacteria ◽  
Pollution Source ◽  
Nitrifying Bacteria ◽  
Channel Water ◽  
River Bed ◽  
Hydraulic Conditions ◽  
Major Floods ◽  
Shallow Stream ◽  
Stream Bed

A project investigating the dynamics of self-purification processes in a shallow stream is carried out. Effects of the concentration gradient due to the distance to the pollution source, of hydraulic conditions in the river bed and of storm floods on the distribution of nitrifying bacteria were studied with the help of laboratory and field experiments. Nitrifiers density on the surface of the stream bed increased rapidly up to a distance of 300 m from the WWTP indicating possible competition of the nitrifiers with the heterotrophic bacteria close to the WWTP. Afterwards a slight decrease in the downstream direction was observed. In vertical profiles, higher bacterial densities were found at sites with rapid infiltration of channel water to the stream bed than at sites with no exchange between channel water and stream bed water or where stream bed water exfiltrated. A major flood event scoured the nitrifiers nearly totally from the surface of the river bed. Major floods belong so to the most dominant processes controlling self-purification in shallow streams. Minor floods, however, don't scour bacteria in the depth of the stream bed that could then be important for the self-purification processes.

Nitrogen removal from livestock and poultry breeding wastewaters using a novel sequencing batch biofilm reactor

2010 ◽  
Vol 62 (11) ◽  
pp. 2599-2606 ◽  
Author(s):  
Hong Xiao ◽  
Ping Yang ◽  
Hong Peng ◽  
Yanzong Zhang ◽  
Shihuai Deng ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Heterotrophic Bacteria ◽  
Biofilm Reactor ◽  
N Accumulation ◽  
Sequencing Batch Biofilm Reactor ◽  
Poultry Breeding ◽  
Mode 2 ◽  
Do Concentration ◽  
Nitrification And Denitrification ◽  
Biological Nitrogen

A study was conducted regarding the biological nitrogen removal from the livestock and poultry breeding wastewater (LPBWs) using a novel sequencing batch biofilm reactor (SBBR). Nitrogen removal process was studied under three aeration strategies/modes, referred to as MODE 1, 2, and 3. The results showed that MODE 2 (one operation period: instant fill of LPBWs, 3.0 h aeration, 1.5 h non-aeration, 1.5 h aeration, 1.0 h non-aeration and rapid drain of treated LPBWs) performed the best in nitrogen removal. Under MODE 2, the removal efficiencies were as high as 96.1 and 92.1% for NH3-N and TN, respectively. Simultaneous nitrification and denitrification (SND), as well as shortcut nitrification and denitrification are likely to be the two main mechanisms for the nitrogen removal in this study. Nitrifying bateria were not inhibited by heterotrophic bacteria with C/N ratios ranging from 18.1 to 21.4 and DO concentration of 2.0 mg/l. Alternation between aeration and non-aeration played an important role in NO2−-N accumulation.

Transport and reaction of aromatics, O2 and CO2 within a membrane bound biofilm in competition with suspended biomass

1995 ◽  
Vol 31 (1) ◽  
pp. 129-141 ◽  
Author(s):  
Oliver Debus
Keyword(s):  
Gas Phase ◽  
Transport Processes ◽  
Pure Oxygen ◽  
Bulk Liquid ◽  
Bulk Fluid ◽  
Biofilm Thickness ◽  
Suspended Biomass ◽  
Membrane Bound ◽  
Laboratory Reactor ◽  
Experimental Values

The biological removal of volatile o-, m-, p-xylene and ethylbenzene from the bulk fluid was investigated in a stirred laboratory reactor. The biofilm was grown on a gas-permeable silicone membrane tubing through which oxygen was supplied. A mathematical simulation could adequately reproduce the experimental values for the biofilm thickness and the concentrations for several species for both sides of the biofilm: in the bulk liquid and in the gas phase. A high xylene conversion plateau of more than 90% was determined by the chronologically occurrence of two sub-maxima: conversion by suspended biomass and by the biofilm. The two maxima can be explained by the spatial transport processes of oxygen and xylene in the biofilm. The first sub-maximum of the conversion by suspended biomass is determined by a maximum oxygen flux through the membrane-bound biofilm. Later oxygen becomes limiting in the bulk and less xylene is degraded by suspended biomass and a maximum transport of xylene into the biofilm occurred, which led to a maximum conversion of xylene within the biofilm. For biodegradable organic compounds, the biofilm can totally reduce the transfer of these compounds into the gas phase. If compounds are non-degradable a biofilm with a thickness of 2 mm reduces the transfer into the gas phase only by 35%. Therefore, the application of pure oxygen and low volumetric gas rates are necessary to reduce the transfer of compounds that are not biodegradable. The transfer of CO2 into the gas phase of the membrane-bound biofilm is very important for the stabilization of the pH in the biofilm and the bulk. The transfer of CO2 from the biofilm into the gas phase is up to 6 times higher than the transfer of CO2 from the biofilm into the bulk. The pH-minimum in the biofilm is not more than 0.15 pH-units below the pH in the bulk.

scholarly journals Evaluation of culturable, nitrifying, ammonium-oxidizing, and metabolically active bacteria in shrimp farm effluents of Kino Bay, Sonora, México

2012 ◽  
Vol 64 (3) ◽  
pp. 895-909 ◽  
Author(s):  
Nolberta Huerta-Aldaz ◽  
M.A. López-Torres ◽  
J.E. Valdez-Holguín ◽  
R.H. Barraza-Guardado
Keyword(s):  
Heterotrophic Bacteria ◽  
Natural Populations ◽  
Control Site ◽  
Epifluorescence Microscopy ◽  
Nitrifying Bacteria ◽  
Production Cycle ◽  
Mean Values ◽  
Discharge Area ◽  
Shrimp Farm ◽  
Active Bacteria

Bacteria from shrimp farm effluents in Kino Bay, Sonora, M?xico were evaluated during the 2008 production cycle. The culturable bacterial populations considered were viable heterotrophic bacteria (VHB) and Vibrio-like bacteria (VLB). In addition, total bacteria (TB), metabolically active bacteria (MAB), nitrifying bacteria (NB), and ammonium-oxidizing bacteria (AOB) were quantified by epifluorescence microscopy. Three sampling sites were established in the influence area of drain and one control site far from the discharge area. Average concentrations of VHB and VLB were 103 and 102 CFU mL-1, respectively. The TB ranged from 107 to 109 cells mL-1. The mean values of Mrelated to TB counts in the affected area were higher throughout the culture cycle compared to the control site, ranging from 1.09 to 27.35%. These results indicate that effluents modify the natural loads of bacteria in the discharge area, which could affect natural populations and the microbial balance of the area.

Clogging limitation of nitrifying biofilters: BiostyrDuo® process study

2019 ◽  
Vol 14 (1) ◽  
pp. 43-54
Author(s):  
Vincent Rocher ◽  
Romain Mailler ◽  
Perrine Mèche ◽  
Sébastien Pichon ◽  
Jean Bernier ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Operating Conditions ◽  
Nitrifying Bacteria ◽  
Tight Control ◽  
Filtration Time ◽  
Process Study ◽  
Fixed Film ◽  
Key Factor ◽  
The Media ◽  
Nitrification And Denitrification

Abstract The biological conventional removal of nitrogen is achieved through nitrification and denitrification steps using several types of technologies, including fixed-film reactors. This type of technology allows the nitrifying bacteria to grow on a media that remains inside the reactor. This process requires tight control and is known to progressively clog during treatment as the filtered particles accumulate and biofilm grows on the media. Thus, clogging management is generally considered as a key factor in biofiltration. So, increasing the filtration time and reducing the number of backwashes are possible ways of achieving a more efficient nitrification step. The objective of the work presented here is to verify the influence of a media, named K5, added to the Biostyr® beads inside a biofilter. With a greater density than Biostyr® beads, this media stays at the bottom of the biofilter and improves operating conditions, reducing both the headloss during filtration time and the number of backwashes. The addition of such media in biofilters may reduce significantly the energy consumption of the process and the risk of hydraulic short-circuiting while limiting biofilter clogging.

scholarly journals Assessment of the nitrification process in a culture of pacific white shrimp, using artificial substrate and bacterial inoculum in a biofloc technology system (BFT)

2019 ◽  
Vol 49 (6) ◽  
Author(s):  
Nathalia Brenda Veiga dos Santos ◽  
Plínio Schmidt Furtado ◽  
Dionéia Evangelista César ◽  
Wilson Wasielesky Junior
Keyword(s):  
Heterotrophic Bacteria ◽  
Pacific White Shrimp ◽  
Production Performance ◽  
Artificial Substrates ◽  
Nitrifying Bacteria ◽  
Clear Water ◽  
Technology System ◽  
Working Volume ◽  
Significant Difference ◽  
Nitrification Process

ABSTRACT: Litopenaeus vannamei is the most cultured marine shrimp in all types of systems including the Bioflocs Technology System (BFT). Bioflocs are formed by microorganisms, among these, autotrophic bacteria are responsible for the nitrification process. This study aimed to identify and promote the development of nitrifying bacteria by adding artificial substrates and biofloc inoculum in L. vannamei culture in a BFT system. The experiment consisted of four treatments with three replics (4x3) as follows: (1) Control: clear water in which bioflocs were formed; (2) IN (10%): clear water with biofloc inoculum (10%); (3) IB: clear water with substrate (immature “bioballs”); and (4) MB: clear water with mature “bioballs” inoculum from a recirculation system. Treatments were stocked with shrimp juveniles (4.92±0.45 g) in 12 tanks with 200 L working volume at a stocking density of 200 shrimp/m³. Shrimps were fed twice a day with a commercial feed (38% CP) following a feeding table, and daily observations intake were made over the four weeks of the experiment. Biofloc and “bioballs” samples were collected to detect the growth of the population of nitrifying and heterotrophic bacteria by FISH. There was no significant difference between treatments (P>0.05) for survival, obtaining mean values greater than 88%. The IN (10%) treatment had lower concentrations of ammonia and nitrite, and nitrate concentration increased, while MB had a higher weight and biomass final, productivity, weekly weight gain and lower conversion of apparent feed for production performance results.

Nitrogen Removal by a Submerged Biofilm Process with Fibrous Carriers

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2039-2042 ◽  
Author(s):  
B. Wang ◽  
G. Li ◽  
Q. Yang ◽  
R. Liu
Keyword(s):  
Nitrogen Removal ◽  
Return Flow ◽  
Organic Substances ◽  
Optimal Conditions ◽  
Flow Ratio ◽  
Nitrification And Denitrification ◽  
Biofilm Process

A study on nitrogen removal by submerged biofilm attaching on fibrous carriers in A/0 process was carried out, with the emphasis put on finding out the optimal conditions for nitrification and denitrification with highest nitrogen removal. The influence of return flow ratio of nitrified effluent on the removal capacities of the system for organic substances and nitrogen was studied as well.

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