Optimization of sulfide‐based autotrophic denitrification process in an anaerobic baffled reactor

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.

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Nitrate Removal from Actual Wastewater by Coupling Sulfur-Based Autotrophic and Heterotrophic Denitrification under Different Influent Concentrations

Water ◽

10.3390/w13202913 ◽

2021 ◽

Vol 13 (20) ◽

pp. 2913

Author(s):

Feng Liu ◽

Suqin Wang ◽

Xuezhi Zhang ◽

Feiyue Qian ◽

Yaobing Wang ◽

...

Keyword(s):

Removal Efficiency ◽

Nitrate Removal ◽

Operating Conditions ◽

Coupled Systems ◽

Polluted Water ◽

Sequencing Analysis ◽

Autotrophic Denitrification ◽

Actual Wastewater ◽

Denitrification Process ◽

Heterotrophic Denitrification

Contamination of wastewater with organic-limited nitrates has become an urgent problem in wastewater treatment. The cooperating heterotrophic with sulfur autotrophic denitrification is an alternative process and the efficiency has been assessed in many studies treating simulated wastewater under different operating conditions. However, due to the complex and diverse nature of actual wastewater, more studies treating actual wastewater are still needed to evaluate the feasibility of collaborative denitrification. In this study, lab-scale experiments were performed with actual nitrate polluted water of two different concentrations, with glucose and sodium thiosulfate introduced as mixed electron donors in the coupling sulfur-based autotrophic and heterotrophic denitrification. Results showed that the optimum denitrification performance was exhibited when the influent substrate mass ratio of C/N/S was 1.3/1/1.9, with a maximum denitrification rate of 3.52 kg NO3−-N/(m3 day) and nitrate removal efficiency of 93% in the coupled systems. Illumina high-throughput sequencing analysis revealed that autotrophic, facultative, and heterotrophic bacteria jointly contributed to high nitrogen removal efficiency. The autotrophic denitrification maintained as the predominant process, while the second most prevalent denitrification process gradually changed from heterotrophic to facultative with the increase of influent concentration at optimum C/N/S ratio conditions. Furthermore, the initiation of dissimilatory nitrate reduction to ammonium (DNRA) was very pivotal in promoting the entire denitrification process. These results suggested that sulfur-based autotrophic coupled with heterotrophic denitrifying process is an alternative and promising method to treat nitrate containing wastewater.

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Simultaneous heterotrophic and sulfur-oxidizing autotrophic denitrification process for drinking water treatment: Control of sulfate production

Water Research ◽

10.1016/j.watres.2011.09.056 ◽

2011 ◽

Vol 45 (20) ◽

pp. 6661-6667 ◽

Cited By ~ 87

Author(s):

Erkan Sahinkaya ◽

Nesrin Dursun ◽

Adem Kilic ◽

Sevgi Demirel ◽

Sinan Uyanik ◽

...

Keyword(s):

Drinking Water ◽

Water Treatment ◽

Drinking Water Treatment ◽

Autotrophic Denitrification ◽

Treatment Control ◽

Sulfate Production ◽

Sulfur Oxidizing ◽

Denitrification Process

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How to ascertain the importance of autotrophic denitrification process in a bioelectrochemical system

Bioresource Technology ◽

10.1016/j.biortech.2013.07.133 ◽

2013 ◽

Vol 146 ◽

pp. 525-529 ◽

Cited By ~ 9

Author(s):

Baocheng Huang ◽

Huajun Feng ◽

Meizhen Wang ◽

Na Li ◽

Yanqing Cong ◽

...

Keyword(s):

Autotrophic Denitrification ◽

Bioelectrochemical System ◽

Denitrification Process

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MODEL ESTIMASI BIOKINETIKA UNTUK PROSES POST-DENITRIFIKASI AIR LIMBAH DOMESTIK PADA UNIT ANAEROBIC BAFFLED REACTOR

JURNAL SUMBER DAYA AIR ◽

10.32679/jsda.v17i2.701 ◽

2021 ◽

Vol 17 (2) ◽

pp. 69-82

Author(s):

Allen Kurniawan ◽

Fatihaturrizky Amelia ◽

Adhirajasa Wirayudhatama ◽

Sulpa Yudha Prawira

Keyword(s):

Substrate Concentration ◽

Volatile Fatty Acids ◽

High Strength ◽

Hydrolysis Rate ◽

Yield Coefficient ◽

Continuous Stirred Tank Reactor ◽

Acid Fermentation ◽

Anaerobic Baffled Reactor ◽

Wastewater Quality ◽

Denitrification Process

This study developed a combination of Continuous Stirred Tank Reactor (CSTR) for the acid fermentation and the Anaerobic Baffled Reactor (ABR) post-denitrification through high nitrite injection. Volatile Fatty Acids (VFAs) as a substrate for the post-denitrification process were optimally produced in the acid fermentation process. The aim of this study was to obtain the estimation of biokinetic values to predict the effluent wastewater quality in ABR post-denitrification process under unsteady state. The reactor was operated for HRT 7 days at temperature 25-28 ˚C and pH 6-7,2. The influent and effluent substrate concentration were monitored continuously for 160 days. Post-denitrification biokinetic from the Contois equation resulted in the value of hydrolysis rate (Kh) of 0.077 day-1, the substrate transport rate (k) of 4.364×10-6 Lmg-1day-1, maximum specific growth rate (μmax) of 0.559 day-1, half saturation constant (KS) of 0.209 mgL-1, microbial decay coefficient (b) of 0.0145 days-1; yield coefficient (Y) of 0.084 g-VSSg-COD-1. The validation of biokinetic parameters based on statistical analysis showed fairly precise results following the trend of experimental data to determine the substrate concentration in the effluent unit. Therefore, the biokinetic values can be applied in the design of ABR post-denitrification using primary sludge incorporation with high strength nitrate.Keywords: Anaerobic baffled reactor, biokinetics, Contois, hydrolysis, post-denitrification.

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