Evaluation of sulfur-based autotrophic denitrification and denitritation for biological removal of nitrate and nitrite from contaminated waters

Biological Removal NOx from Simulated Flue gas in aerobic biofilter, by Jiang R., Huang S.B. and Yang J.

Global NEST Journal ◽

10.30955/gnj.000502 ◽

2013 ◽

Vol 10 (2) ◽

pp. 241-248

Keyword(s):

Gas Phase ◽

Flue Gas ◽

Removal Rate ◽

Nox Removal ◽

Biological Removal ◽

Oxidation Reduction ◽

Oxidation Reduction Potential ◽

O2 Concentration ◽

Blank Experiment ◽

Nitrate And Nitrite

A bench-scale biofiltration system was developed to evaluate the NOx removal efficiency under high oxygen concentration. The system had been running for 120 days and kept on a steady NOx removal rate above 80%. A stable NOx removal with an efficiency of more than 80% from the gas phase can be obtained by the bioreactor concept, when flue gas containing NO (400-600 ppmv) and a certain O2 concentration (0-20%). In the blank experiment, less than 35% NO was removed as oxygen increased. The tendency of the three curves about NO removal rate with various O2 concentrations was mainly similar but some differences in the highest and lowest removal rate happened in the definite O2 concentration range. Oxygen was shown to have a significant effect on NOx removal at the first two or three days when oxygen concentration increased sharply. The higher concentration NO influent gas contained, the longer time the microflora need to regain activities. Compared with humidifier, microbial regenerator which was incorporated in biofilter can improve aerobic denitrifying bacteria activity by applying alternating oxic–anoxic conditions in the presence of nitrate and nitrite. Oxidation-Reduction Potential (ORP) and Dissolved Oxygen (DO) were used to control the dose of carbon source.

Download Full-text

Effect of sulfide concentration on autotrophic denitrification from nitrate and nitrite in vertical fixed-bed reactors

Process Biochemistry ◽

10.1016/j.procbio.2012.05.008 ◽

2012 ◽

Vol 47 (9) ◽

pp. 1395-1401 ◽

Cited By ~ 60

Author(s):

B.S. Moraes ◽

T.S.O. Souza ◽

E. Foresti

Keyword(s):

Fixed Bed ◽

Sulfide Concentration ◽

Autotrophic Denitrification ◽

Fixed Bed Reactors ◽

Nitrate And Nitrite

Download Full-text

Simultaneous biological removal of sulphide and nitrate by autotrophic denitrification in an activated sludge system

Water Science & Technology ◽

10.2166/wst.2006.410 ◽

2006 ◽

Vol 53 (12) ◽

pp. 91-99 ◽

Cited By ~ 28

Author(s):

I. Manconi ◽

A. Carucci ◽

P. Lens ◽

S. Rossetti

Keyword(s):

Activated Sludge ◽

Removal Efficiency ◽

Electron Donor ◽

Product Formation ◽

Fish Analysis ◽

Autotrophic Denitrification ◽

Biological Removal ◽

N Removal ◽

Activated Sludge Reactor ◽

Denitrification Process

The feasibility of an autotrophic denitrification process in an activated sludge reactor, using sulphide as the electron donor, was tested for simultaneous denitrification and sulphide removal. The reactor was operated at nitrate (N) to sulphide (S) ratios between 0.5 and 0.9 to evaluate their effect on theN-removal efficiency, the S-removal efficiency and the product formation during anoxic oxidation of sulphide. One hundred per cent removal of both nitrate and sulphide was achieved at a NLR of 7.96 mmol N·L−1·d−1 (111.44 mg NO3−-N·L−1·d−1) and at a N/S ratio of 0.89 with complete oxidation of sulphide to sulphate. The oxygen level in the reactor (10%) was found to influence the N-removal efficiency by inhibiting the denitrification process. Moreover, chemical (or biological) oxidation of sulphide with oxygen occurred, resulting in a loss of the electron donor. FISH analysis was carried out to study the microbial population in the system.

Download Full-text