Biological denitrification of drinking water using autotrophic organisms with H2 in a fluidized-bed biofilm reactor

1987 ◽  
Vol 29 (4) ◽  
pp. 493-501 ◽  
Author(s):  
M. Kurt ◽  
I. J. Dunn ◽  
J. R. Bourne
1992 ◽  
Vol 26 (3-4) ◽  
pp. 555-566 ◽  
Author(s):  
V. Z. Lazarova ◽  
B. Capdeville ◽  
L. Nikolov

The properties of two biofilms generated with different predominant organisms were studied in a laboratory-scale fluidized bed bioreactor. Bed expansion, biofilm thickness, biofilm density, protein and polysaccharide concentrations were measured and compared. A high polysaccharide concentration was observed in the less dense and more fragile biofilm of Ps. aeruginosa. The more active biofilm of Ps. stutzeri was characterized by higher protein concentration and density. The results demonstrated that the biofilm performance mostly depended on the physiological characteristics of the preponderant organism. Complete nitrate reduction was reached in both biofilms at very low biofilm thickness. Elevated residual nitrite was observed only in the biofilm of Ps. aeruginosa.


2004 ◽  
Vol 4 (5-6) ◽  
pp. 21-28
Author(s):  
S.-C. Kim ◽  
D.-K. Lee

TiO2-coated granular activated carbon was employed for the removal of toxic microcystin-LR from water. High surface area of the activated carbon provided sites for the adsorption of microcystin-LR, and the adsorbed microcystin-LR migrated continuously onto the surface of TiO2 particles which located mainly at the exterior surface in the vicinity of the entrances of the macropores of the activated carbon. The migrated microcystin-LR was finally degraded into nontoxic products and CO2 very quickly. These combined roles of the activated carbon and TiO2 showed a synergistic effect on the efficient degradation of toxic microcystin-LR. A continuous flow fluidized bed reactor with the TiO2-coated activated carbon could successfully be employed for the efficient photocatalytic of microcystin-LR.


1999 ◽  
Vol 22 (5) ◽  
pp. 389-395 ◽  
Author(s):  
Noriyo NISHIJIMA ◽  
Tetsuya TANAKA ◽  
Kouichi TSUZUKI ◽  
Takeo TAKAGI

1994 ◽  
Vol 30 (11) ◽  
pp. 101-110
Author(s):  
Toshiaki Tsubone ◽  
Seiichi Kanamori ◽  
Tatsuo Takechi ◽  
Masahiro Takahashi

A pilot scale study was conducted using an Air-Fluidized-Bed Biofilm Reactor (AFBBR) system with a Multi Media Filter (MMF). Soluble BOD (S-BOD) concentration in the effluent of the AFBBR had a correlation with total BOD (T-BOD) and Suspended Solids (SS) concentration in the effluent of the MMF. The lower the S-BOD in the effluent of the AFBBR was, the lower was not only T-BOD but also SS in the effluent of the MMF. It was found that as treatment proceeded, S-BOD was removed and the particle size of SS increased in the AFBBR. These results suggested that the mechanism of BOD removal in this system was: S-BOD was removed and a part of the S-BOD was changed to SS and the particle size of the SS increased in the AFBBR, and then the SS was removed by the MMF. Thus not only the T-BOD but also the SS in the effluent of MMF was lower when the S-BOD in the effluent of the AFBBR was lower. When the S-BOD in the effluent of the AFBBR was 8mg/L, T-BOD and the SS in the effluent of the MMF were 10mg/L and 4mg/L, respectively. In order to have an average S-BOD value in the effluent of the AFBBR of about 8mg/L, the T-BOD loading and the S-BOD loading needed to be less than 1.3kg/m3/day and 0.45 kg/m3/day, respectively. Even when the BOD loading was high, nitrification still occurred in this system.


1991 ◽  
Vol 23 (7-9) ◽  
pp. 1347-1354 ◽  
Author(s):  
F. Trinet ◽  
R. Heim ◽  
D. Amar ◽  
H. T. Chang ◽  
B. E. Rittmann

A three-phase, liquid-fluidized-bed biofilm reactor was operated over wide ranges of liquid velocity, air velocity, medium concentration, and substrate surface loading. The biofilm characteristics (total colonization, polysaccharide content, density, and thickness) and the specific detachment coefficient (bs) were determined by a combination of experimental measurements and a hydrodynamic model. The results demonstrated that dense and thin biofilms were induced by the physical condition of high particle-to-particle contacts and high liquid turbulence. The biofilm's polysaccharide content was increased by increased air turbulence and a low substrate availability. The specific detachment coefficient, bs, was strongly correlated to the concentration of the medium (negatively) and the polysaccharide content (positively). Overall, the bs can be controlled significantly by the gas and liquid velocities; increasing either velocity tends to increase bs.


1982 ◽  
Author(s):  
B.D. Patton ◽  
C.W. Hancher ◽  
W.W. Pitt ◽  
J.F. Walker

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