Insights into complete nitrate removal in one-stage nitritation-anammox by coupling heterotrophic denitrification

2021 ◽  
Vol 298 ◽  
pp. 113431
Author(s):  
Pian-Pian Xu ◽  
Jia Meng ◽  
Xianhui Li ◽  
Jiuling Li ◽  
Kai Sun ◽  
...  
Keyword(s):  
Nitrate Removal ◽  
One Stage ◽  
Heterotrophic Denitrification

Optimal operations for groundwater denitrification of drinking water using heterotrophic biological denitrification process

2006 ◽  
Vol 6 (2) ◽  
pp. 125-130
Author(s):  
C.-H. Hung ◽  
K.-H. Tsai ◽  
Y.-K. Su ◽  
C.-M. Liang ◽  
M.-H. Su ◽  
...  
Keyword(s):  
Drinking Water ◽  
Removal Efficiency ◽  
Nitrate Removal ◽  
Drinking Water Treatment ◽  
Nitrate Content ◽  
Source Water ◽  
Nitrogen Gas ◽  
Negative Effect ◽  
Denitrification Process ◽  
Heterotrophic Denitrification

Due to the extensive application of artificial nitrogen-based fertilizers on land, groundwater from the central part of Taiwan faces problems of increasing concentrations of nitrate, which were measured to be well above 30 mg/L all year round. For meeting the 10 mg/L nitrate standard, optimal operations for a heterotrophic denitrification pilot plant designed for drinking water treatment was investigated. Ethanol and phosphate were added for bacteria growing on anthracite to convert nitrate to nitrogen gas. Results showed that presence of high dissolved oxygen (around 4 mg/L) in the source water did not have a significantly negative effect on nitrogen removal. When operated under a C/N ratio of 1.88, which was recommended in the literature, nitrate removal efficiency was measured to be around 70%, sometimes up to 90%. However, the reactor often underwent severe clogging problems. When operated under C/N ratio of 1.0, denitrification efficiency decreased significantly to 30%. Finally, when operated under C/N ratio of 1.5, the nitrate content of the influent was almost completely reduced at the first one-third part of the bioreactor with an overall removal efficiency of 89–91%. Another advantage for operating with a C/N ratio of 1.5 is that only one-third of the biosolids was produced compared to a C/N value of 1.88.

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 Nitrate removal from wastewater generated in wet Flue Gas Desulphurisation Systems (FGD) in coal-fired power generation using the heterotrophic denitrification method

2020 ◽  
Vol 31 (3) ◽  
pp. 27-34
Author(s):  
Krzysztof Iskra ◽  
Łukasz Krawczyk ◽  
Jan M. Miodoński ◽  
Dominika Wierzbicka-Kopertowska
Keyword(s):  
Flue Gas ◽  
Nitrate Nitrogen ◽  
Nitrate Removal ◽  
Oxygen Demand ◽  
Active Surface ◽  
Adaptation Period ◽  
Technological Parameters ◽  
Rate Test ◽  
High Degree ◽  
Heterotrophic Denitrification

Abstract The article presents an assessment of the possibilities of using the heterotrophic denitrification process to remove nitrates from wastewater produced in wet flue gas desulphurisation (FGD) installations and also its optimization in the scope of basic technological parameters. This kind of wastewater is characterized by high salinity (even up to 40,000 g/m3), high temperature (up to 50°C) and low biodegradability, which is expressed by the biochemical oxygen demand (BOD5). The experimental rig consisted of a storage tank and a bioreactor in the form of a bed with an apparatus for measuring basic parameters (temperature, pH, nitrate nitrogen). After an initial adaptation period, a high degree of nitrate nitrogen removal from wastewater (exceeding 95% reduction) was obtained with a reaction time of 180 minutes during the denitrification rate test (NUR). It was also determined that the optimal loading range of the active surface of the bed of 300 m2/m3 should be between 1.5–2.5 gN-NO3/m2·d. The results of the study show that when the required conditions for the development of microorganisms are provided, it is possible to fully adapt the denitrification biomass to the adverse composition of wastewater from wet FGD unit.

Nitrate removal by simultaneous sulfur utilizing autotrophic and heterotrophic denitrification under different organics and alkalinity conditions: batch experiments

2003 ◽  
Vol 47 (1) ◽  
pp. 237-244 ◽  
Author(s):  
S.E. Oh ◽  
M.S. Bum ◽  
Y.B. Yoo ◽  
A. Zubair ◽  
I.S. Kim
Keyword(s):  
Production Rate ◽  
Organic Compounds ◽  
Nitrate Nitrogen ◽  
Nitrogen Concentration ◽  
Nitrate Removal ◽  
Batch Reactors ◽  
Autotrophic Denitrification ◽  
Batch Experiments ◽  
Sulfate Production ◽  
Heterotrophic Denitrification

The effect of various organic compounds were tested using lab-scale batch reactors. At sufficient alkalinity, the initial nitrate nitrogen concentration of 100 mg/L was completely reduced in all batch reactors. Sulfate production decreased by the addition of organics. The concentration range of organics used in this experiment did not inhibit autotrophic denitrification except for propionate. Propionate inhibited autotrophic denitrification a little, indicated by a lower sulfate production rate. Biomass in suspension increased with higher initial organic concentrations, showing higher DOC consumption. As the concentration of organics increased, alkalinity increased accordingly. Under the conditions of low alkalinity, in the case of a control reactor without organics, only about 30% of the initial nitrate was reduced. With half the theoretically required dosage of methanol, the denitrification rates increased slightly. When ethanol, acetate, and propionate were used, denitrification went to completion. When excess organics was added, however, sulfate production was significantly decreased. Interestingly, even when small amounts of organics were added, autotrophic denitrification was promoted as indicated by the sulfate production.

scholarly journals Hydrilla verticillata–Sulfur-Based Heterotrophic and Autotrophic Denitrification Process for Nitrate-Rich Agricultural Runoff Treatment

2020 ◽  
Vol 17 (5) ◽  
pp. 1574
Author(s):  
Qianyu Hang ◽  
Haiyan Wang ◽  
Zan He ◽  
Weiyang Dong ◽  
Zhaosheng Chu ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Nitrate Removal ◽  
Hydrilla Verticillata ◽  
Agricultural Runoff ◽  
Denitrification Rate ◽  
Phase Iii ◽  
Autotrophic Denitrification ◽  
N Removal ◽  
Significant Difference ◽  
Heterotrophic Denitrification

Hydrilla verticillata–sulfur-based heterotrophic and autotrophic denitrification (HSHAD) process was developed in free water surface constructed wetland mesocosms for the treatment of nitrate-rich agricultural runoff with low chemical oxygen demand/total nitrogen (C/N) ratio, whose feasibility and mechanism were extensively studied and compared with those of H. verticillata heterotrophic denitrification (HHD) mesocosms through a 273-day operation. The results showed that the heterotrophic and autotrophic denitrification can be combined successfully in HSHAD mesocosms, and achieve satisfactory nitrate removal performance. The average NO3−-N removal efficiency and denitrification rate of HSHAD were 94.4% and 1.3 g NO3−-N m−3·d−1 in steady phase II (7–118 d). Most nitrate was reduced by heterotrophic denitrification with sufficient organic carbon in phase I (0–6 d) and II, i.e., the C/N ratio exceeded 4.0, and no significant difference of nitrate removal capacity was observed between HSHAD and HHD mesocosms. During phase III (119–273 d), sulfur autotrophic denitrification gradually dominated the HSHAD process with the C/N ratio less than 4.0, and HSHAD mesocosms obtained higher NO3−-N removal efficiency and denitrification rate (79.1% and 1.1 g NO3−-N m−3·d−1) than HHD mesocosms (65.3% and 1.0 g NO3−-N m−3·d−1). As a whole, HSHAD mesocosms removed 58.8 mg NO3−-N more than HHD mesocosms. pH fluctuated between 6.9–9.0 without any pH buffer. In general, HSHAD mesocosms were more stable and efficient than HHD mesocosms for NO3−-N removal from agricultural runoff during long-term operation. The denitrificans containing narG (1.67 × 108 ± 1.28 × 107 copies g−1 mixture-soil−1), nirS (8.25 × 107 ± 8.95 × 106 copies g−1 mixture-soil−1), and nosZ (1.56 × 106 ± 1.60 × 105 copies g−1 mixture-soil−1) of litter bags and bottoms in HSHAD were higher than those in HHD, which indicated that the combined heterotrophic and autotrophic denitrification can increase the abundance of denitrificans containing narG, nirS, and nosZ, thus leading to better denitrification performance.

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