The heterotrophic-combined-with-autotrophic denitrification process: performance and interaction mechanisms

2015 ◽  
Vol 71 (8) ◽  
pp. 1212-1218 ◽  
Author(s):  
Guihua Xu ◽  
Cuijie Feng ◽  
Fang Fang ◽  
Shaohua Chen ◽  
Yuanjian Xu ◽  
...  
Keyword(s):  
Chemical Oxygen Demand ◽  
Reduction Rate ◽  
Oxygen Demand ◽  
Process Performance ◽  
Autotrophic Denitrification ◽  
N Accumulation ◽  
Interaction Mechanisms ◽  
Molar Ratios ◽  
Denitrification Process ◽  
Heterotrophic Denitrification

In this work, the interaction mechanisms between an autotrophic denitrification (AD) and heterotrophic denitrification (HD) process in a heterotrophic-autotrophic denitrification (HAD) system were investigated, and the performance of the HAD system under different S/Ac− molar ratios was also evaluated. The results demonstrated that the heterotrophic-combined-with-autotrophic denitrification process is a promising technology which can remove chemical oxygen demand (COD), sulfide and nitrate simultaneously. The reduction rate of NO3− to NO2− by the HD process was much faster than that of reducing NO2− to N2, while the reduction rate of NO3− to NO2− by the AD process was slower than that of NO2− to N2. Therefore, the AD process could use the surplus NO2− produced by the HD process. This could alleviate the NO2−–N accumulation and increase the denitrification rate. In addition, the inhibition effects of acetate on AD bacteria and sulfide on HD were observed, and the inhibition was compensated by the promotion effects on NO2−. Therefore, the processes of AD and HD seem to react in parallel, without disturbing each other, in our HAD system.

scholarly journals Feasibility of Adjusting the S2O32−/NO3− Ratio to Adapt to Dynamic Influents in Coupled Anammox and Denitrification Systems

2020 ◽  
Vol 17 (7) ◽  
pp. 2200
Author(s):  
Yuqian Hou ◽  
Shaoju Cheng ◽  
Mengliang Wang ◽  
Chenyong Zhang ◽  
Bo Liu
Keyword(s):  
16S Rrna ◽  
Chemical Oxygen Demand ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Oxygen Demand ◽  
Granular Sludge ◽  
Autotrophic Denitrification ◽  
Rrna Sequencing ◽  
Total Nitrogen Removal ◽  
Heterotrophic Denitrification

In this study, anammox, sulfur-based autotrophic denitrification, and heterotrophic denitrification (A/SAD/HD) were coupled in an expanded granular sludge bed (EGSB) reactor to explore the feasibility of enhancing denitrification performance by adjusting the S2O32−/NO3− (S/N) ratio to accommodate dynamic influents. The results indicated that the optimal influent conditions occurred when the conversion efficiency of ammonium (CEA) was 55%, the S/N ratio was 1.24, and the chemical oxygen demand (COD) was 50 mg/L, which resulted in a total nitrogen removal efficiency (NRE) of 95.0% ± 0.5%. The S/N ratio regulation strategy was feasible when the influent COD concentration was less than 100 mg/L and the CEA was between 57% and 63%. Characterization by 16S rRNA sequencing showed that Candidatus Jettenia might have contributed the most to anammox, while Thiobacillus and Denitratisoma were the dominant taxa related to denitrification. The findings of this study provide insights into the effects of CEA and COD on the performance of the A/SAD/HD system and the feasibility of the S/N ratio regulation strategy.

scholarly journals A two-stage soil infiltration system incorporated with heterotrophic denitrification (TSISHD) for urban runoff treatment

2015 ◽  
Vol 47 (1) ◽  
pp. 128-136
Author(s):  
Lizhu Hou ◽  
Xue Xu ◽  
Yiran Song ◽  
Chuanping Feng
Keyword(s):  
Carbon Sources ◽  
Oxygen Demand ◽  
Urban Runoff ◽  
Quality Standard ◽  
Soil Infiltration ◽  
Class V ◽  
National Quality ◽  
Removal Efficiencies ◽  
Denitrification Process ◽  
Heterotrophic Denitrification

To enhance denitrification performance of soil infiltration, a soil infiltration system incorporated with heterotrophic denitrification (TSISHD) for urban runoff treatment was developed. Sawdust and grass powders were added in the anaerobic stage (ANS) to provide organic carbon sources for the denitrification process, and the reduction environment was improved by iron addition in the ANS. Aerobic respiration and nitrification primarily occurred in the upper aerobic stage (AES), which removed 86.68% of the chemical oxygen demand (COD) and 91.80% of the NH+4-N. Moreover, heterotrophic denitrification occurred in the bottom ANS when added sawdust and grass powders were used as a carbon source. Overall, the TSISHD showed remarkable removal efficiencies of 88.29%, 82.50%, 92.05%, and 78.10% for COD, NO−3-N, NH+4-N, and total phosphorus, respectively, and the corresponding effluent concentrations met the national quality standard of China for class V surface water. The removal efficiencies were significantly higher than those of the previous soil infiltration systems without inoculated microbes. The developed system has the potential to treat urban runoff.

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

Water ◽  
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.

scholarly journals Experimental Investigation of Sludge Treatment Using a Rotor-Stator Type Hydrodynamic Cavitation Reactor and an Ultrasonic Bath

Processes ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 790 ◽  
Author(s):  
Hyunsoo Kim ◽  
Xun Sun ◽  
Bonchan Koo ◽  
Joon Yong Yoon
Keyword(s):  
Chemical Oxygen Demand ◽  
Reduction Rate ◽  
Oxygen Demand ◽  
Hydrodynamic Cavitation ◽  
Volume Index ◽  
Treatment Technique ◽  
Cross Sectional ◽  
Sludge Treatment ◽  
Ultrasonic Bath ◽  
Oxidation Performance

In the present work, the sludge treatment performance of a sludge treatment using a rotor-stator type hydrodynamic cavitation reactor (HCR) was investigated. To verify the performance, a comparison with an ultrasonic bath was conducted in four experimental cases using three assessment factors. The HCR consisted of a rotor and three covers with inserted dimples resulting in variation of the cross-sectional area in a flow. The experimental cases were established using the same energy consumption for each device. Disintegration performance was analyzed with assessment factors using particle size distribution and sludge volume index (SVI), oxidation performance using total chemical oxygen demand (TCOD) and volatile suspended solids (VSS) reduction rate, as well as solubilization rate using soluble chemical oxygen demand (SCOD). As a result, the particle disintegration and oxidation performance of the HCR were generally superior to those of the ultrasonic bath. However, due to the contradictory interactions of these factors, the solubilization rate of the two devices was measured similarly as 42.3% and 41.4% for each device. Results of the current study proved that the HCR can be an effective, promising and clean sludge treatment technique for use in wastewater treatment plants.

Operation strategies for psychrophilic anaerobic digestion of swine manure slurry in sequencing batch reactors

1996 ◽  
Vol 23 (6) ◽  
pp. 1285-1294 ◽  
Author(s):  
D. I. Massé ◽  
N. K. Patni ◽  
R. L. Droste ◽  
K. J. Kennedy
Keyword(s):  
Anaerobic Digestion ◽  
Chemical Oxygen Demand ◽  
Stable Process ◽  
Swine Manure ◽  
Oxygen Demand ◽  
Batch Reactors ◽  
Process Performance ◽  
Sequencing Batch Reactors ◽  
Pollution Potential ◽  
Manure Slurry

The objective of this study was to evaluate the performance of psychrophilic anaerobic digestion in sequencing batch reactors (SBRs) under operating strategies that would optimize process performance and stability while minimizing the interference of the bioreactor operation with regular farm activities. Process performance was evaluated on (i) reduction in pollution potential; (ii) energy recovery; and (iii) odour reduction. Experiments were carried out in twelve 40-L SBRs. Experimental results indicated that psychrophilic anaerobic digestion of swine manure slurry at 20 °C in an intermittently fed SBR (i) reduced the pollution potential of swine manure slurry by removing 84 – 93% of the soluble chemical oxygen demand and 41 – 83% of total chemical oxygen demand; (ii) produced biogas at rates exceeding 0.48 L of CH4 per gram of volatile solids fed; and (iii) successfully reduced odours. Other findings were that (i) for all experimental runs, psychrophilic anaerobic digestion of swine manure slurry in SBRs was very stable; (ii) the process generally performed well without external mixing; and (iii) intermittent feeding of once or three times a week did not affect process stability and performance. As a result, this process requires little energy input and most of the energy produced will be available for farm use. Since this process is very stable, process feeding could be integrated with the routine operation of manure removal from the barn, thereby minimizing interference with other farm operations. Key words: anaerobic, anaerobic treatment, psychrophilic, animal manure, methane production, process control, manure treatment.

REMOVAL OF DYE AND CHEMICAL OXYGEN DEMAND (COD) REDUCTION FROM TEXTILE INDUSTRIAL WASTEWATER USING HYBRID BIOREACTORS

2014 ◽  
Vol 13 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Ghasem Najafpour Darzi ◽  
Reza Katal ◽  
Hossein Zare ◽  
Seyed Omid Rastegar ◽  
Poorya Mavaddat
Keyword(s):  
Chemical Oxygen Demand ◽  
Industrial Wastewater ◽  
Oxygen Demand ◽  
Cod Reduction
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