Nitrate Removal from Groundwater by Denitrification in Fixed and Fluidized Bed Biofilm Reactors A Comparative Study

The influence of attached biomass bioreactor types on the denitrification process using a low-pitched groundwater containing nitrates was studied. Two types of fixed-bed and fluidized-bed biofilm reactors, equipped with expanded clay granular filler, with a particle size fraction of 2-5 mm were used. The nitrite and nitrate concentrations in the inflow and outflow of the two bioreactors were analytically determined. Based on the obtained concentration values, the denitrification rates were calculated, ranging between 1275�1387 g NO3-N/m3/day in the case of the fixed bioreactor and between 3390�3867 g NO3-N/m3/day in the case of the fluidized bed bioreactor.

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Oxygen reduces denitrification in biofilm reactors

Water Science & Technology ◽

10.2166/wst.1994.0749 ◽

1994 ◽

Vol 29 (10-11) ◽

pp. 83-91 ◽

Cited By ~ 7

Author(s):

C. Hagedorn-Olsen ◽

I. H. Møller ◽

H. Tøttrup ◽

P. Harremoës

Keyword(s):

Organic Matter ◽

Oxygen Concentration ◽

Nitrate Removal ◽

Full Scale ◽

Laboratory Scale ◽

Oxygen Penetration ◽

Biofilm Reactors ◽

Fixed Film ◽

Half Power ◽

Denitrification Process

The mechanism for the nitrate removal from wastewater in a submerged fixed film filter is reviewed and evaluated to demonstrate that the denitrification process is significantly reduced by the presence of oxygen. The kinetics were developed for a fully nitrate penetrated biofilm, influenced by oxygen. It was demonstrated that there is a linear reduction of the denitrification rate with depth of oxygen penetration, proportional to the oxygen concentration to the half power. For a partly nitrate penetrated biofilm the influence of oxygen is a function of the ratio between the penetration of oxygen and the penetration of nitrate without the influence of oxygen. The phenomenon was investigated in laboratory scale with biocarbone and biostyr as media and at a full scale biocarbone plant. The investigation was performed with organic matter in excess on a thin biofilm taken directly from a full scale plant. The results of the experiments with influence of oxygen fit the kinetic concepts well.

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Nitrate Removal of Fluidized-Bed Biofilm Reactors Using Starch / Polyvinyl Alcohol Blends as Carbon Source and Carrier Simultaneously at Low Temperature

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.501-504.2089 ◽

2014 ◽

Vol 501-504 ◽

pp. 2089-2092

Author(s):

Hai Hong Zhou ◽

Fang He

Keyword(s):

Drinking Water ◽

Controlled Release ◽

Low Temperature ◽

Carbon Source ◽

Polyvinyl Alcohol ◽

Fluidized Bed ◽

Nitrate Concentration ◽

Nitrate Removal ◽

Biofilm Reactors ◽

Resident Time

A kind of controlled-release carbon source, starch / polyvinyl alcohol blends (SPVA), was used as both carbon source and biofilm supporter in laboratory-scale fluidized-bed biofilm reactors (FBBRs) to remove nitrate from groundwater. Results show: when the influent nitrate concentration was 100 mg-N /L, FBBRs packed with SPVA can effectively remove nitrate from groundwater at the condition of temperature 20 °C, hydraulic resident time (HRT) 4 h. The effluent nitrate can meet with the Chinese drinking water standards at low temperature (15-2 °C) by adjusted the HRT of FBBRs. The denitrification rate declined nonlinearly with the decrease of temperature and changed sharply in the range of 20-15 °Cand 10-5 °C.

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Nitrate removal characteristics of high performance fluidized-bed biofilm reactors

Water Research ◽

10.1016/j.watres.2004.07.002 ◽

2004 ◽

Vol 38 (17) ◽

pp. 3719-3728 ◽

Cited By ~ 55

Author(s):

Fahid K. J. Rabah ◽

Mohamed F. Dahab

Keyword(s):

Fluidized Bed ◽

High Performance ◽

Nitrate Removal ◽

Biofilm Reactors

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Modelling and Experiments on Fluidized-Bed Biofilm Reactors

Water Science & Technology ◽

10.2166/wst.1991.0184 ◽

1991 ◽

Vol 24 (7) ◽

pp. 47-58 ◽

Cited By ~ 11

Author(s):

L. Bignami ◽

B. Eramo ◽

R. Gavasci ◽

R. Ramadori ◽

E. Rolle

Keyword(s):

Fluidized Bed ◽

Liquid Velocity ◽

Fluid Dynamic ◽

Fixed Bed ◽

Experimental Tests ◽

Rational Basis ◽

Biofilm Reactors ◽

Bed Porosity ◽

Batch Tests ◽

Biofilm Model

Over the last few years considerable attention has been devoted to biological fluidized-bed technology which seems to be potentially more advantageous than both dispersed biomass processes and fixed bed systems. An obstacle to the spreading of this technology is the lack of rigorous criteria in designing reactors, due to the poor knowledge of interconnections of fluid-dynamic aspects with kinetic ones. This paper reviews the rational basis for reactor design and reports on the experimental tests carried out in order to gain a better understanding in the areas of biofilm modelling and fluidization mechanics. In particular a biofilm model, in the general case of the Michaelis and Menten equation, was developed and its validity was verified utilizing experimental data obtained in nitrifying batch tests. As to fluidization mechanics the experimental work confirms the Wen and Yu(1966) approach to correlate the bed porosity with the superficial liquid velocity.

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Pemodelan Reaktor Hibrid Anaerob Pengolah Molasse Pada Pembebanan Organik Tinggi

10.31219/osf.io/q9dth ◽

2020 ◽

Author(s):

Gede H Cahyana

Keyword(s):

Fluidized Bed ◽

Fixed Bed ◽

High Rate ◽

Upflow Anaerobic Sludge Blanket ◽

Anaerobic Sludge ◽

Expanded Bed ◽

Anaerobic Sludge Blanket

Telah dikembangkan reaktor anaerob kecepatan tinggi (high rate) yang merupakan modifikasi reaktor konvensional. Di antaranya berupa (bio)reaktor pertumbuhan tersuspensi (contoh: UASB, Upflow Anaerobic Sludge Blanket) dan reaktor pertumbuhan lekat (Fixed Bed atau Biofilter, Fluidized Bed, Expanded Bed, Rotating Biodisc dan Baffled Reactor). Kedua tipe reaktor di atas memiliki sejumlah kelebihan dan kekurangan. Untuk mengoptimalkan nilai positifnya (terutama untuk keperluan desain) maka reaktor tersebut, pada penelitian ini, disusun menjadi satu urutan yang disebut Reaktor Hibrid Anaerob (Rehan) yakni UASB di bawah dan AF di atasnya. Lebih lanjut, penelitian ini diharapkan dapat memberikan informasi tentang kinerja Rehan dalam mengolah air limbah (substrat) yang konsentrasi zat organiknya (COD) sangat tinggi dan suatu model matematika yang dapat mewakili reaktor tersebut.

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Optimal operations for groundwater denitrification of drinking water using heterotrophic biological denitrification process

Water Science & Technology Water Supply ◽

10.2166/ws.2006.060 ◽

2006 ◽

Vol 6 (2) ◽

pp. 125-130

Author(s):

C.-H. Hung ◽

K.-H. Tsai ◽

Y.-K. Su ◽

C.-M. Liang ◽

M.-H. Su ◽

...

Keyword(s):

Drinking Water ◽

Removal Efficiency ◽

Nitrate Removal ◽

Drinking Water Treatment ◽

Nitrate Content ◽

Source Water ◽

Nitrogen Gas ◽

Negative Effect ◽

Denitrification Process ◽

Heterotrophic Denitrification

Due to the extensive application of artificial nitrogen-based fertilizers on land, groundwater from the central part of Taiwan faces problems of increasing concentrations of nitrate, which were measured to be well above 30 mg/L all year round. For meeting the 10 mg/L nitrate standard, optimal operations for a heterotrophic denitrification pilot plant designed for drinking water treatment was investigated. Ethanol and phosphate were added for bacteria growing on anthracite to convert nitrate to nitrogen gas. Results showed that presence of high dissolved oxygen (around 4 mg/L) in the source water did not have a significantly negative effect on nitrogen removal. When operated under a C/N ratio of 1.88, which was recommended in the literature, nitrate removal efficiency was measured to be around 70%, sometimes up to 90%. However, the reactor often underwent severe clogging problems. When operated under C/N ratio of 1.0, denitrification efficiency decreased significantly to 30%. Finally, when operated under C/N ratio of 1.5, the nitrate content of the influent was almost completely reduced at the first one-third part of the bioreactor with an overall removal efficiency of 89–91%. Another advantage for operating with a C/N ratio of 1.5 is that only one-third of the biosolids was produced compared to a C/N value of 1.88.

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