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

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

Water Science & Technology Water Supply ◽

10.2166/ws.2006.060 ◽

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.

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Effect of current on biofilm-electrode reactor coupled with sulfur autotrophic denitrification process (BER-SAD) for nitrate removal from wastewater

E3S Web of Conferences ◽

10.1051/e3sconf/202126702021 ◽

2021 ◽

Vol 267 ◽

pp. 02021

Author(s):

Hengyuan Liu ◽

Chenhe Zhang

Keyword(s):

Removal Efficiency ◽

Current Density ◽

Nitrate Removal ◽

Great Influence ◽

Current Intensity ◽

Autotrophic Denitrification ◽

Nitrite Production ◽

Coupled Process ◽

Denitrification Process

The biofilm-electrode reactor coupled with sulfur autotrophic denitrification process (BER-SAD) was used to remove nitrate in groundwater, and the effect of current intensity on the denitrification characteristics of the coupled process was explored. Current intensity had a great influence on the denitrification effect of the coupled process, the maximum nitrate removal efficiency of 99.9% and lowest nitrite production were gained under the optimum current density of 100 mA. Moreover, the accumulation concentration of SO42- increased gradually with the increase of current intensity. With the increase of current intensity, the proportion of hydrogen autotrophic denitrification decreased, while the proportion of sulfur autotrophic denitrification increased.

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

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17051574 ◽

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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Simultaneous oxidation and reduction treatments of polluted water by a bio-electro reactor

Water Science & Technology ◽

10.2166/wst.1996.0187 ◽

1996 ◽

Vol 34 (9) ◽

pp. 101-108 ◽

Cited By ~ 11

Author(s):

M. Kuroda ◽

T. Watanabe ◽

Y. Umedu

Keyword(s):

Aqueous Solution ◽

Organic Matter ◽

Electric Current ◽

Removal Efficiency ◽

Concentration Ratio ◽

Nitrate Removal ◽

Hydrogen Gas ◽

Polluted Water ◽

Simultaneous Oxidation ◽

Denitrifying Microorganisms

Application of a bio-electro reactor for treatment of various kinds of polluted water was investigated experimentally. Aqueous solution of nitrate, ammonium and/or organic matter were used as synthetic polluted water. Denitrification of the nitrate polluted water without organic matter proceeded effectively by utilizing hydrogen gas produced by electrolysis of water in the reactor. The bio-electro reactor was also available for the treatment of nitrate polluted water containing organic matter when the C/N concentration ratio was up to 1.0 under the condition of 100 mA of applied electric current. The nitrate removal efficiency from nitrate polluted water containing acetate at C/N=1.0 was more than 90% at 5 hours of HRT and 80% even at 2.8 h HRT. For the treatment of ammonium polluted water, nitrification and denitrification proceeded simultaneously in a bio-electro reactor where nitrifying and denitrifying microorganisms were immobilized on the electrodes. The results obtained in this study suggested that the bio-electro reactor system was capable to application for oxidation and reduction treatments of the nitrate and ammonium polluted water.

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Simultaneous biological removal of sulphide and nitrate by autotrophic denitrification in an activated sludge system

Water Science & Technology ◽

10.2166/wst.2006.410 ◽

2006 ◽

Vol 53 (12) ◽

pp. 91-99 ◽

Cited By ~ 28

Author(s):

I. Manconi ◽

A. Carucci ◽

P. Lens ◽

S. Rossetti

Keyword(s):

Activated Sludge ◽

Removal Efficiency ◽

Electron Donor ◽

Product Formation ◽

Fish Analysis ◽

Autotrophic Denitrification ◽

Biological Removal ◽

N Removal ◽

Activated Sludge Reactor ◽

Denitrification Process

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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Modelling Nutrients and Organics Removal by Biological Slow Filtration in Micro-Polluted Water Source Treatment

Processes ◽

10.3390/pr6080128 ◽

2018 ◽

Vol 6 (8) ◽

pp. 128 ◽

Cited By ~ 1

Author(s):

Chengjin Zhang ◽

Jian He ◽

Zheng Zheng

Keyword(s):

Removal Efficiency ◽

Filtration Rate ◽

Degradation Mechanism ◽

Water Source ◽

Biological Indicators ◽

Hydraulic Head ◽

Operating Conditions ◽

Polluted Water ◽

Removal Rates ◽

Slow Filtration

The biological slow filtration (BSF) system as a simple and efficient environmental technology has been widely applied in treatment of ‘micro-polluted’ water. At present, many related studies have focused on the removal efficiency of biological indicators (such as bacteria and viruses). However, there is less research on the removal performance of nutrients and organics in the BSF system. In this paper, we employed a lab-scale biological slow filter to study the removal efficiency and degradation mechanism of nutrients and organics. We proved through adsorption of filter layer at the early running stage and biodegradation at the later stage, the BSF system could achieve effective removal of NH3-N, TN, TP, CODMn and turbidity and the corresponding removal rates are 83.65%, 42.45%, 42.94%, 60.41% and 83.55%, respectively. Furthermore, we also explored the influence of four main factors (filtration rate, filter depth, hydraulic head and temperature) and their interactions on removal rates of nutrients and organics in the BSF system and obtained the optimal operating parameters as follows: filtration rate 0.1 m/h, filter depth 0.8 m, hydraulic head 0.64 m, temperature 26.06 °C. This study would provide a theoretical foundation for the actual application of biological slow filter in treatment of micro-polluted water in developing countries and offer an optimized basis for the design of operating conditions.

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Modeling of nitrate removal from aqueous solution by Fe-doped TiO2 under UV and solar irradiation using response surface methodology

Global NEST Journal ◽

10.30955/gnj.001577 ◽

2015 ◽

Vol 17 (2) ◽

pp. 379-388 ◽

Cited By ~ 3

Keyword(s):

Aqueous Solution ◽

Response Surface Methodology ◽

Solar Radiation ◽

Response Surface ◽

Removal Efficiency ◽

Nitrate Removal ◽

Operating Conditions ◽

Solar Irradiation ◽

Design Matrix ◽

Statistical Tool

<div> Nitrate is a common groundwater pollutant all over the world. In some regions of Iran, its levels are high enough to cause serious problems to human health and the environment. The objectives of this work were to evaluate the efficiency of Fe-doped TiO2 nanoparticles at removing nitrate from aqueous solutions under UV and solar radiation and to model nitrate removal using response surface methodology techniques. In this study, a response surface methodology based on the Box–Behnken design matrix was used to describe the process of nitrate removal from an aqueous solution with four independent parameters, namely Fe-doped TiO2 (dose 1-2 g l-1), nitrate concentration (25-100 mg l-1), contact time (10-120 min), and pH (4-9). The results indicated that the removal efficiency of nitrate in the presence of ultraviolet and solar radiation was 56.5 % and 21.8%, respectively. The removal efficiency of nitrate increased with time and initial concentration of nitrate. Analysis of variance (ANOVA) indicated that the proposed model was essentially in accordance with the experimental results with the correlation coefficient R2 = 0.9237 and Adj-R2 = 0.8347. Response surface methodology (RSM) proved to be a powerful statistical tool for investigating the operating conditions for nitrate removal under UV irradiation. </div>

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Performance and microbial community of a novel PVA/iron-carbon (Fe–C) immobilized bioreactor for nitrate removal from groundwater

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2020-0158 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Qiong Wen ◽

Junfeng Su ◽

Guoqing Li ◽

Tinglin Huang ◽

Lei Xue ◽

...

Keyword(s):

Removal Efficiency ◽

High Throughput Sequencing ◽

Nitrate Removal ◽

Sequencing Analysis ◽

N Accumulation ◽

N Removal ◽

Carbon Nitrogen Ratio ◽

Nitrogen Ratio ◽

Denitrification Bioreactor ◽

Main Component

Abstract An efficient immobilized denitrification bioreactor functioning under anaerobic conditions was developed by combining bacterial immobilization technology with iron-carbon (Fe–C) particles. The effects of key factors on nitrate (NO3 −–N) removal efficiency were invested, such as the carbon-nitrogen ratio (C/N), pH and hydraulic retention time (HRT). Experimental results show that 100.00% NO3 −–N removal efficiency and a low level of nitrite (NO2 −–N) accumulation less than 0.05 mg L−1 were obtained under the condition of a C/N ratio of 3, pH 7.0 and HRT of 6 h. Meteorological chromatographic analysis showed that the final product of denitrification was mainly nitrogen (N2). The main component of precipitation formed in the bioreactor was characterized as Fe3O4 by X-ray diffraction. High-throughput sequencing analysis indicated that the dominant bacterial class in the Fe–C bioreactor was Gammaproteobacteria, while the dominant genera were Zoogloea and Azospira, the relative abundances of which were as high as 23.25 and 15.43%, respectively.

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

Water Science & Technology ◽

10.2166/wst.2003.0061 ◽

2003 ◽

Vol 47 (1) ◽

pp. 237-244 ◽

Cited By ~ 38

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.

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PENGOLAHAN AIR LINDI DENGAN PROSES BIOFILTER ANAEROB-AEROB DAN DENITRIFIKASI

Jurnal Air Indonesia ◽

10.29122/jai.v8i1.2380 ◽

2018 ◽

Vol 8 (1) ◽

Author(s):

Nusa Idaman Said ◽

Dinda Rita Krishumartani Hartaja

Keyword(s):

Removal Efficiency ◽

Retention Time ◽

Nitrate Removal ◽

Quality Standards ◽

Ammonia Removal ◽

Leachate Treatment ◽

Denitrification Reactor ◽

Aerobic Reactor ◽

Environment Agency ◽

Denitrification Process

Most of the leachate treatment in Indonesia using pond system, that is maturation ponds, anaerobic ponds, stabilization ponds, and continued using wetland. The weakness of this technology is long retention time (between 30-50 days), thus the building a pond requires a wide area. In addition, the processed leachate is over quality standards to be discharged into the environment agency. To overcome these problems, one alternative is to use a combination of processing leachate within anaerobic-aerobic biofilter and denitrification. The technology is expected to shorten the residence time, so that the land required for the processing of leachate is not too extensive . The processed leachate is also expected to meet the quality standards are allowed to be discharged into the environment. Leachate treatment using anaerobic - aerobic biofilter and the denitrification process with a total hidraulic retention time of 12 day, the retention time in the anaerobic reactor 8 ( eight ) days , the retention time in the aerobic reactor 3 (three) days and retention time in the denitrification reactor 1 (one) day can be generated COD removal efficiency of 97 %, ammonia removal efficiency of 97.56 %, TSS removal efficiency 87.5 % , and nitrate removal efficiency of 86.4 % Keywords : Anaerob-aerob biofilter, denitrification, leachate.

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