Competition between planktonic and fixed microorganisms during the start-up of methanogenic biofilm reactors

Aerobic and anaerobic ammonium oxidation can be combined in a completely mixed moving bed biofilm reactor, allowing for single-stage ammonium removal from wastewater with low COD/N ratio unsuitable for conventional nitrification/denitrification processes (‘deammonification’). Mandatory preconditions are: (a) a low hydraulic retention time to wash out suspended cells competing with mass transfer limited biofilm cells for alkalinity as limiting substrate; and (b) an oxygen flux adapted to the surface loading rate to prevent complete nitrification to nitrate. pH control or ‘NH3 inhibition’ of nitrite oxidation are neither useful nor necessary. By this strategy, oxygen limited biofilms with simultaneous presence of NH4-N and NO2-N were enriched, which allowed for growth of anaerobic ammonium oxidizers. It could be demonstrated that a deammonifying reactor can be purposefully started up within a reasonable span of time and without prior inoculation, if this explicitly described strategy is applied. Depending on surface loading and air flow rate, N removal rates of 4–5 g N/m2 d could be achieved at DO concentrations between 1.0 and 4.0 mg/l.

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Start up of an anaerobic inverse turbulent bed reactor fed with wine distillery wastewater using pre-colonised bioparticles

Water Science & Technology ◽

10.2166/wst.2005.0019 ◽

2005 ◽

Vol 51 (1) ◽

pp. 153-158 ◽

Cited By ~ 14

Author(s):

C. Arnaiz ◽

S. Elmaleh ◽

J. Lebrato ◽

R. Moletta

Keyword(s):

Industrial Wastewater ◽

Hydraulic Retention Time ◽

Loading Rate ◽

Oxygen Demand ◽

Anaerobic Treatment ◽

Organic Loading Rate ◽

Organic Loading ◽

Biofilm Reactors ◽

Start Up ◽

Distillery Wastewater

The long start-up period of fluidized bed biofilm reactors is a serious obstacle for their wide installation in the anaerobic treatment of industrial wastewater. This paper presents the results of an anaerobic inverse turbulent bioreactor treating distillery wastewater during 117 days of operation at a laboratory scale. The pre-colonized bioparticles for this work were obtained from a similar reactor processing the same wastewater and which had a start-up period of 3 months. The system attained carbon removal efficiency rates between 70 and 92%, at an organic loading rate of 30.6 kg m+3 d+1 (chemical oxygen demand) with a hydraulic retention time of 11.1 h. The results obtained showed that the start-up period of this kind of reactors can be reduced by 3 using pre-colonized bioparticles.

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Anammox start-up in sequencing batch biofilm reactors using different inoculating sludge

Applied Microbiology and Biotechnology ◽

10.1007/s00253-012-4427-z ◽

2012 ◽

Vol 97 (13) ◽

pp. 6057-6064 ◽

Cited By ~ 19

Author(s):

Ying-Cui Yu ◽

Da-Wen Gao ◽

Yu Tao

Keyword(s):

Biofilm Reactors ◽

Start Up ◽

Sequencing Batch Biofilm Reactors

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Treatment of mountain refuge wastewater by fixed and moving bed biofilm systems

Water Science & Technology ◽

10.2166/wst.2004.0832 ◽

2004 ◽

Vol 48 (11-12) ◽

pp. 169-177 ◽

Cited By ~ 1

Author(s):

G. Andreottola ◽

E. Damiani ◽

P. Foladori ◽

P. Nardelli ◽

M. Ragazzi

Keyword(s):

Wastewater Treatment ◽

Fixed Bed ◽

Treatment Plant ◽

Biofilm Reactor ◽

Moving Bed ◽

Trickling Filters ◽

Advantages And Disadvantages ◽

Biofilm Reactors ◽

Adequate Knowledge ◽

Start Up

Tourists visiting mountain refuges in the Alps have increased significantly in the last decade and the number of refuges and huts at high altitude too. In this research the results of an intensive monitoring of a wastewater treatment plant (WWTP) for a tourist mountain refuge located at 2,981 m a.s.l. are described. Two biofilm reactors were adopted: (a) a Moving Bed Biofilm Reactor (MBBR); (b) a submerged Fixed Bed Biofilm Reactor (FBBR). The aims of this research were: (i) the evaluation of the main parameters characterising the processes and involved in the design of the wastewater plants, in order to compare advantages and disadvantages of the two tested alternatives; (ii) the acquisition of an adequate knowledge of the problems connected with the wastewater treatment in alpine refuges. The main results have been: (i) a quick start-up of the biological reactors obtainable thanks to a pre-colonization before the transportation of the plastic carriers to the refuge at the beginning of the tourist season; (ii) low volume and area requirement; (iii) significantly higher removal efficiency compared to other fixed biomass systems, such as trickling filters, but the energy consumption is higher.

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High NH4+-N concentration wastewater treatment by shortcut nitriﬁcation–denitriﬁcation using a system of A/O inner loop fluidized bed biofilm reactors

Water Science & Technology ◽

10.2166/wst.2013.575 ◽

2013 ◽

Vol 67 (5) ◽

pp. 1083-1091 ◽

Cited By ~ 3

Author(s):

X. M. Hu ◽

Y. W. Chen ◽

Y. G. Liao ◽

W. F. Yan ◽

S. M. Zhu ◽

...

Keyword(s):

Fluidized Bed ◽

Material Balance ◽

Ammonia Nitrogen ◽

Biofilm Reactor ◽

Ammonia Oxidizing Bacteria ◽

High Concentration ◽

Biofilm Reactors ◽

Start Up ◽

High Ammonia ◽

Rapid Mass

In this experiment, a rapid mass-transfer inner loop fluidized bed biofilm reactor (ILFBBR) was employed to treat synthetic high ammonia nitrogen-containing (NH4+-N) wastewater by shortcut nitriﬁcation–denitriﬁcation. The reactor operation was stable after a short start-up period. Ammonia oxidizing bacteria (AOB) were predominant and 65% nitrite (NO2−-N/NOx−-N) levels were achieved. During the nitriﬁcation–denitriﬁcation period, the removal rates of NH4+-N and total nitrogen (TN) reached 94 and 82%, respectively. From the material balance, it was indicated that 87% of NH4+-N was removed by shortcut nitrification. The features of ILFBBR and the beneﬁts of shortcut nitrification were combined in this experiment, and showed an excellent removal of NH4+-N from high-concentration NH4+-N wastewater.

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Observations during start-up of biological phosphorus removal in biofilm reactors

Water Science & Technology ◽

10.2166/wst.2000.0475 ◽

2000 ◽

Vol 41 (4-5) ◽

pp. 425-432 ◽

Cited By ~ 3

Author(s):

P.A. Castillo ◽

S. González-Martínez ◽

I. Tejero

Keyword(s):

Phosphorus Removal ◽

Genetic Material ◽

Domestic Sewage ◽

Cod Removal ◽

Synthetic Wastewater ◽

Biological Phosphorus Removal ◽

Biofilm Reactors ◽

Start Up ◽

P Accumulation ◽

Biological Phosphorus

This research describes the start-up phase of Biological Phosphorus Removal (BPR) processes in two reactors. A Submerged Fix Bed Reactor (SFBR) working with a mixture of synthetic wastewater and domestic sewage and seeded with activated sludge coming from a BPR facility. A second reactor, a Biofilm Membrane Reactor (BMR), was fed with synthetic wastewater and seeded with a mixture of a pure culture of Acinetobacter lwoffi and fresh domestic sewage. It was found that Organic Loading Rates (OLR) above 5 gCOD/m2·d do not guarantee the adequate Mean Cellular Retention Time (MCRT) for the development of Poly-P organisms. Anaerobic periods should not be short during start-up phase or facultative bacteria will efficiently compete for food and, eventually, facing long aerobic periods, the Poly-P organisms may not need the phosphate mechanism to survive short anaerobic periods. Even if COD removal is observed during the anaerobic phase, further P accumulation during the aerobic phase will not be significant, unless the COD removal results in PHB formation. A loss in the BPR capacity of the Poly-P microorganisms was observed after seeding a reactor with active Poly-P organisms. The drop of BPR activity after seeding a reactor with active Poly-P organisms can be caused by the loss of genetic material due to the new environmental conditions and the new influent substrate.

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