Microbial community in methanogenic packed-bed reactor successfully operating at short hydraulic retention time

The effects of hydraulic retention time (HRT) and influent nitrate-N concentration on nitrogen removal and the microbial community composition of an aerobic denitrification reactor treating recirculating marine aquaculture system effluent were evaluated. Results showed that over 98% of nitrogen was removed and ammonia-N and nitrite-N levels were below 1 mg/L when influent nitrate-N was below 150 mg/L and HRT over 5 h. The maximum nitrogen removal efficiency and nitrogen removal rate were observed at HRT of 6 or 7 h when influent nitrate-N was 150 mg/L. High-throughput DNA sequencing analysis revealed that the microbial phyla Proteobacteria and Bacteroidetes were predominant in the reactor, with an average relative total abundance above 70%. The relative abundance of denitrifying bacteria of genera Halomonas and Denitratisoma within the reactor decreased with increasing influent nitrate-N concentrations. Our results show the presence of an aerobically denitrifying microbial consortium with both expected and unexpected members, many of them relatively new to science. Our findings provide insights into the biological workings and inform the design and operation of denitrifying reactors for marine aquaculture systems.

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Effects of hydraulic retention time on the performance and microbial community of an anaerobic baffled reactor-bioelectricity Fenton coupling reactor for treatment of traditional Chinese medicine wastewater

Bioresource Technology ◽

10.1016/j.biortech.2019.121508 ◽

2019 ◽

Vol 288 ◽

pp. 121508 ◽

Cited By ~ 6

Author(s):

Chengyuan Su ◽

Qiujin Deng ◽

Yuxiang Lu ◽

Ronghua Qin ◽

Shenglong Chen ◽

...

Keyword(s):

Microbial Community ◽

Chinese Medicine ◽

Traditional Chinese Medicine ◽

Retention Time ◽

Hydraulic Retention Time ◽

Anaerobic Baffled Reactor

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Biodegradation of 2,4-dichlorophenol in Packed-Bed Biofilm Reactor: Effect of Hydraulic Retention Time, Biogenic Substrate, and Loading Rate

Water Environment Research ◽

10.2175/106143016x14733681695726 ◽

2016 ◽

Vol 88 (12) ◽

pp. 2191-2197 ◽

Cited By ~ 1

Author(s):

Bhishma P. Patel ◽

Arvind Kumar

Keyword(s):

Retention Time ◽

Hydraulic Retention Time ◽

Loading Rate ◽

Packed Bed ◽

Biofilm Reactor ◽

Biogenic Substrate

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Autotrophic denitrification of landfill leachate using elemental sulphur

Water Science & Technology ◽

10.2166/wst.1996.0584 ◽

1996 ◽

Vol 34 (5-6) ◽

pp. 469-476 ◽

Cited By ~ 49

Author(s):

A. Koenig ◽

L. H. Liu

Keyword(s):

Particle Size ◽

Retention Time ◽

Hydraulic Retention Time ◽

Loading Rate ◽

Nitrate Removal ◽

Packed Bed ◽

Elemental Sulphur ◽

Limiting Factor ◽

Autotrophic Denitrification ◽

Sulphur Particle

One of the most economical means of nitrogen removal from leachate is biological treatment by nitrification, followed by heterotrophic denitrification. An alternative biological denitrification process is autotrophic denitrification using Thiobacillus denitrificans. This autotrophic bacteria oxidizes elemental sulphur to sulphate while reducing nitrate to elemental nitrogen gas, thereby eliminating the need for addition of organic carbon compounds. For this study, pilot-scale elemental sulphur packed bed columns with fixed-film denitrification have been selected as the most suitable treatment process. The effect of hydraulic retention time as well as the effect of concentration and loading rate of nitrate on nitrate removal efficiency as a function of sulphur particle size were determined. The results indicate that (i) autotrophic denitrification can effectively remove nitrate from synthetic and actual nitrified leachate at concentrations much higher than hitherto reported; (ii) the minimum hydraulic retention time necessary for complete denitrification depends on sulphur particle size; (iii) the maximum area loading rate, in g NO3−-N/m2·d, appears to be the process limiting factor and is practically independent of sulphur particle size; and (iv) the observed stoichiometric relationships compare well with those previously reported.

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