Effect of hydraulic retention time on sulfate reduction in a carbon monoxide fed thermophilic gas lift reactor

Treatment of acidic Fe (II)- and sulfate-rich mine waters represents a major problem in many areas of the world. Therefore, a process was developed which utilises naturally occurring sulfate-reducing microorganisms for the elimination of sulfate and of part of the acidity from the acidic mine water. In order to improve the performance of this biological sulfate reduction process an in-depth analysis of the microbial diversity and activity in dependence of the hydraulic retention time (HRT) and other process parameters used to run the bioreactors was undertaken. This comparison demonstrated a positive correlation between shorter HRT and increasing sulfate reduction rates. The improvement in performance with decreasing HRT was paralleled by an increase of the total enzymatic activity (measured as hydrolase activity) of the microbial community and of the biomass (measured as protein concentration) in the bioreactors. A partial taxonomic identification of the microbial community in the bioreactors was achieved via nucleotide sequence analysis of a clone library of PCR-amplified 16S rRNA gene fragments prepared from a sample of the microbial biofilm in the bioreactor. Additionally, the genetic fingerprint technique T-RFLP was used to assess temporal changes of the microbial community in the biofilm within the reactor.

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Effect of Hydraulic Retention Time on Pretreatment of Sulfate-Laden Wastewater for Desulfurization-Denitrification Process

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.113-116.536 ◽

2010 ◽

Vol 113-116 ◽

pp. 536-539

Author(s):

Wei Li ◽

Xiao Liang ◽

Jian Guo Lin

Keyword(s):

Organic Carbon ◽

Sulfate Reduction ◽

Retention Time ◽

Hydraulic Retention Time ◽

Removal Rate ◽

Reduction Stage ◽

Sulfate Removal ◽

Carbon Sulfide ◽

Set Up ◽

Denitrification Process

In order to treat wastewater rich in sulfate and organic carbon, an anaerobic attached-growth bioreactor was set up. It was the pretreatment of desulfurization-denitrification process. At hydraulic retention time of 128h-6.2h, sulfate removal rate and sulfide generating rate took on initial increasing and subsequent decreasing. At hydraulic retention time of 7.7h-10.2h, the removals of sulfate and organic carbon, sulfide generating rate reached 95.79%, 80% and 58.82%, respectively. The results showed that the suitable hydraulic retention time in sulfate reduction stage for the pretreatment of desulfurization-denitrification process was 7.7h-10.2h.

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Effect of Hydraulic Retention Time on the Sulfate Reduction Process and Metal Precipitates Characteristics

10.1201/9781003059318-4 ◽

2022 ◽

pp. 75-98

Author(s):

Denys Kristalia Villa Gómez

Keyword(s):

Sulfate Reduction ◽

Retention Time ◽

Hydraulic Retention Time ◽

Reduction Process ◽

Sulfate Reduction Process

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The nitrogen removal potential of predenitrification systems in sensitive coastal areas

Water Science & Technology ◽

10.2166/wst.1995.0218 ◽

1995 ◽

Vol 32 (7) ◽

pp. 135-142

Author(s):

E. Görgün ◽

N. Artan ◽

D. Orhon ◽

R. Tasli

Keyword(s):

Water Quality ◽

Wastewater Treatment ◽

Nitrogen Removal ◽

Retention Time ◽

Treatment Process ◽

Hydraulic Retention Time ◽

Domestic Sewage ◽

Coastal Areas ◽

Careful Evaluation ◽

Denitrification Kinetics

Effective nitrogen removal is now required to protect water quality in sensitive coastal areas. This involves a much more difficult treatment process than for conventional domestic sewage as wastewater quantity and quality exhibits severe fluctuations in touristic zones. Activated sludge is currently the most widely used wastewater treatment and may be upgraded as a predenitrification system for nitrogen removal. Interpretation of nitrification and denitrification kinetics reveal a number of useful correlations between significant parameters such as sludge age, C/N ratio, hydraulic retention time, total influent COD. Nitrogen removal potential of predenitrification may be optimized by careful evaluation of wastewater character and the kinetic correlations.

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Evaluation of a tropical single-cell waste stabilization pond system for irrigation

Water Science & Technology ◽

10.2166/wst.1995.0495 ◽

1995 ◽

Vol 31 (12) ◽

pp. 267-273 ◽

Cited By ~ 4

Author(s):

B. S. O. Ceballos ◽

A. Konig ◽

B. Lomans ◽

A. B. Athayde ◽

H. W. Pearson

Keyword(s):

Single Cell ◽

Removal Efficiency ◽

Retention Time ◽

Hydraulic Retention Time ◽

Full Scale ◽

Waste Stabilization Pond ◽

North East ◽

Helminth Eggs ◽

Waste Stabilization ◽

Better Than

A single full-scale primary facultative pond in Sapé, north-east Brazil was monitored for performance and efficiency. The pond had a hydraulic retention time of 61 days and achieved a 95% BOD5 removal efficiency and had no helminth eggs in the effluent. The effluent failed to meet the WHO faecal coliform guideline for unrestricted irrigation. The pond was dominated by the cyanobacterium Microcystis and gave better than predicted orthophosphate removal. Details of how the system could be simply upgraded utilizing the same land are discussed.

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