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 Biological treatment of leachate from stabilization of biodegradable municipal solid waste in a sequencing batch biofilm reactor

2020 ◽  
Author(s):  
K. Bernat ◽  
M. Zaborowska ◽  
M. Zielińska ◽  
I. Wojnowska-Baryła ◽  
W. Ignalewski
Keyword(s):  
Municipal Solid Waste ◽  
Chemical Oxygen Demand ◽  
Solid Waste ◽  
Oxygen Content ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Biochemical Oxygen Demand ◽  
Oxygen Demand ◽  
Synthetic Wastewater ◽  
Total Nitrogen Removal

Abstract The aim of this study was to determine the effectiveness of pollutant removal in sequencing batch biofilm reactors (with floating or submerged carriers) when treating nitrogen- and organic-rich real leachate generated during aerobic stabilization of the biodegradable municipal solid waste. A control reactor contained suspended activated sludge. The share of leachate in synthetic wastewater was 10%, which resulted in ratios of chemical oxygen demand and biochemical oxygen demand to total Kjeldahl nitrogen in the influent of ca. 11 and ca. 8.5, respectively. Regardless of whether the reactors contained carriers or not, the effectiveness of nitrification (84.2–84.3%) and of the removal of chemical oxygen demand (86.5–87.0%), biochemical oxygen demand (95.5–98.0%) and ammonium (88.9–89.3%) did not differ. However, the presence of carriers and their type determined in which phase of the cycle denitrification occurred. In the control reactor, denitrification took place during mixing phase with the effectiveness of ca. 43.2% (57.7% of the total nitrogen removal). During aeration, the oxygen content increased rapidly, thus reduced the possibility of simultaneous denitrification. In reactors with carriers, in the aeration phase, not only nitrification but also denitrification occurred. The increase in oxygen content in wastewater was slower, which could have caused dissolved oxygen gradients and anoxic zones in deeper layers of the biofilm and flocks. In the reactor with floating carriers, the effectiveness of denitrification and total nitrogen removal increased 1.23- and 1.10-times, respectively, as compared to the control reactor. The highest efficiencies (67.7% and 73.0%, respectively) were observed in the reactor with submerged carriers.

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.

A novel sludge minimized biological nitrogen removal process for saline sewage treatment

2009 ◽  
Vol 59 (10) ◽  
pp. 1893-1899 ◽  
Author(s):  
W. L. Tsang ◽  
J. Wang ◽  
H. Lu ◽  
S. Li ◽  
G. H. Chen ◽  
...  
Keyword(s):  
Sulfate Reduction ◽  
Removal Efficiency ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Sewage Treatment ◽  
Biological Nitrogen Removal ◽  
Autotrophic Denitrification ◽  
Removal Process ◽  
Total Nitrogen Removal ◽  
Biological Nitrogen

This study reports a lab-scale evaluation of a new biological nitrogen removal process for saline sewage treatment, namely a SANI process (Sulfate reduction, Autotrophic denitrification and Nitrification Integrated process). The experimental system consisted of an up-flow anaerobic bed for sulfate reduction, an anoxic filter for autotrophic denitrification using dissolved sulfide produced in the up-flow anaerobic bed and an aerobic filter for nitrification. The system successfully operated for more than 180 days with an overall organic carbon removal efficiency of 95%, in which, 82% removal was contributed by the up-flow anaerobic bed operating at a HRT of 6 h, and 13% removal by the anoxic filter. An average COD removed /sulfate removed ratio was found to be 0.76 gCOD/gSO4 or 2.28 COD/gSO4-S further confirming that the organic removal was mainly achieved by the sulfate reduction. In terms of nitrogen removal efficiency, the SANI system was found sensitive to the recirculation rate between the anoxic filter and the aerobic filter. A recirculation rate of 3Q was found to be optimal for achieving 74% of the total nitrogen removal. It was confirmed that the autotrophic denitrification was a major contributor to the total nitrogen removal in the SANI system. Sulfur balance analysis indicated that both the accumulation of elementary sulfur in the biomass and the loss of hydrogen sulfide were trivial. During the entire operation period (330 days to date), no sludge was wasted from any reactors in this system. This was further confirmed by the biomass balance simulation results that low biomass yields of sulfate reducing bacteria, autotrophic denitrifiers and nitrifiers contribute to the zero excess sludge discharge.

scholarly journals Nitrogen Removal by Sulfur-Based Carriers in a Membrane Bioreactor (MBR)

Membranes ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 115 ◽  
Author(s):  
Thi-Kim-Quyen Vo ◽  
Jeong-Jun Lee ◽  
Joon-Seok Kang ◽  
Seogyeong Park ◽  
Han-Seung Kim
Keyword(s):  
Removal Efficiency ◽  
Total Phosphorus ◽  
Nitrogen Removal ◽  
Membrane Bioreactor ◽  
Oxygen Demand ◽  
Autotrophic Denitrification ◽  
Nitrogen Gas ◽  
Sulfate Ions ◽  
Major Disadvantage ◽  
Bioreactor System

Sulfur-based carriers were examined to enhance the nitrogen removal efficiency in a mixed anoxic–anaerobic-membrane bioreactor system, in which sulfur from the carrier acts as an electron donor for the conversion of nitrate to nitrogen gas through the autotrophic denitrification process. A total nitrogen removal efficiency of 63% was observed in the system with carriers, which showed an increase in the removal efficiency of around 20%, compared to the system without carriers. The results also indicated that the carriers had no adverse effect on biological treatment for the organic matter and total phosphorus. The removal efficiencies for chemical oxygen demand (COD) and total phosphorus (TP) were 98% and 37% in both systems, respectively. The generation of sulfate ions was a major disadvantage of using sulfur-based carriers, and resulted in pH drop. The ratio of sulfate in the effluent to nitrate removed in the system ranged from 0.86 to 1.97 mgSO42−/mgNO3−-N, which was lower than the theoretical value and could be regarded as due to the occurrence of simultaneous heterotrophic and autotrophic denitrification.

Removal of nitrogen from coal gasification wastewater by nitrosofication and denitrosofication

1998 ◽  
Vol 38 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Junxin Liu ◽  
Weiguang Li ◽  
Xiuheng Wang ◽  
Hongyuan Liu ◽  
Baozhen Wang
Keyword(s):  
Nitrogen Removal ◽  
Coal Gasification ◽  
Oxygen Demand ◽  
Test Results ◽  
New Process ◽  
Scale Test ◽  
Coal Gasification Wastewater ◽  
Total Nitrogen Removal ◽  
Biological Nitrogen ◽  
Bench Scale Test

In this paper, a study of a new process with nitrosofication and denitrosofication for nitrogen removal from coal gasification wastewater is reported. In the process, fibrous carriers were packed in an anoxic tank and an aerobic tank for the attached growth of the denitrifying bacteria and Nitrobacter respectively, and the suspended growth activated sludge was used in an aerobic tank for the growth of Nitrosomonas. A bench scale test has been carried out on the process, and the test results showed that using the process, 25% of the oxygen demand and 40% of the carbon source demand can be saved, and the efficiency of total nitrogen removal can increase over 10% as compared with a traditional process for biological nitrogen removal.

Enhancing nitrogen removal efficiency in a dyestuff wastewater treatment plant with the IFFAS process: the pilot-scale and full-scale studies

2017 ◽  
Vol 77 (1) ◽  
pp. 70-78 ◽  
Author(s):  
Yanjun Mao ◽  
Xie Quan ◽  
Huimin Zhao ◽  
Yaobin Zhang ◽  
Shuo Chen ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Full Scale ◽  
Nitrification And Denitrification ◽  
Dyestuff Wastewater

Abstract The activated sludge (AS) process is widely applied in dyestuff wastewater treatment plants (WWTPs); however, the nitrogen removal efficiency is relatively low and the effluent does not meet the indirect discharge standards before being discharged into the industrial park's WWTP. Hence it is necessary to upgrade the WWTP with more advanced technologies. Moving bed biofilm processes with suspended carriers in an aerobic tank are promising methods due to enhanced nitrification and denitrification. Herein, a pilot-scale integrated free-floating biofilm and activated sludge (IFFAS) process was employed to investigate the feasibility of enhancing nitrogen removal efficiency at different hydraulic retention times (HRTs). The results showed that the effluent chemical oxygen demand (COD), ammonium nitrate (NH4+-N) and total nitrogen (TN) concentrations of the IFFAS process were significantly lower than those of the AS process, and could meet the indirect discharge standards. PCR-DGGE and FISH results indicated that more nitrifiers and denitrifiers co-existed in the IFFAS system, promoting simultaneous nitrification and denitrification. Based on the pilot results, the IFFAS process was used to upgrade the full-scale AS process, and the effluent COD, NH4+-N and TN of the IFFAS process were 91–291 mg/L, 10.6–28.7 mg/L and 18.9–48.6 mg/L, stably meeting the indirect discharge standards and demonstrating the advantages of IFFAS in dyestuff wastewater treatment.

scholarly journals Micro-pressure swirl reactor (MPSR) for efficient COD and nitrogen removal of high-concentration wastewater

2020 ◽  
Vol 82 (9) ◽  
pp. 1795-1807 ◽  
Author(s):  
Dejun Bian ◽  
Zebing Nie ◽  
Fan Wang ◽  
Shengshu Ai ◽  
Suiyi Zhu ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Lower Cost ◽  
Batch Reactor ◽  
Oxygen Demand ◽  
Swirl Flow ◽  
High Concentration ◽  
Internal Circulation ◽  
Carbon And Nitrogen ◽  
Pressure Swirl

Abstract A micro-pressure swirl reactor (MPSR) was developed for carbon and nitrogen removal of wastewater, in which dissolved oxygen (DO) gradient and internal circulation could be created by setting the aerators along one side of the reactor, and micro-pressure could be realized by sealing most of the top cap and increasing the outlet water level. In this study, velocity and DO distribution in the reactor was measured, removal performance treating high-concentration wastewater was investigated, and the main functional microorganisms were analyzed. The experiment results indicated that there was stable swirl flow and spatial DO gradient in MPSR. Operated in sequencing batch reactor mode, distinct biological environments spatially and temporally were created. Under the average influent condition of chemical oxygen demand (COD) concentration of 2,884 mg/L and total nitrogen (TN) of 184 mg/L, COD removal efficiency and removal loading was 98% and 1.8 kgCOD/(m3·d) respectively, and TN removal efficiency and removal loading reached up to 90% and 0.11 kgTN/(m3·d) respectively. With efficient utilization of DO and simpler configuration for simultaneous nitrification and denitrification, the MPSR has the potential of treating high-concentration wastewater at lower cost.

Sign in / Sign up

Export Citation Format

Share Document