scholarly journals Nitrogen removal from ammonium-contaminated groundwater using dropping nitrification–cotton-based denitrification reactor

2021 ◽  
Author(s):  
A. K. Maharjan ◽  
K. Mori ◽  
K. Nishida ◽  
T. Toyama
Keyword(s):  
Nitrogen Removal ◽  
Removal Rate ◽  
Denitrifying Bacteria ◽  
Electron Donors ◽  
Nitrifying Bacteria ◽  
Contaminated Groundwater ◽  
Total N ◽  
N Removal ◽  
Denitrification Reactor ◽  
Synthetic Groundwater

Abstract A novel dropping nitrification–cotton-based denitrification reactor was developed for total nitrogen (N) removal from ammonium (NH4+)-contaminated groundwater. The nitrogen removal ability of the reactor was evaluated for 91 days. A 1 m-long dropping nitrification unit was fed with synthetic groundwater containing 30 mg-NH4+-N/L at a flow rate of 2.16 L/d. The outlet of the dropping nitrification unit was connected to the cotton-based denitrification unit. The NH4+ present in the groundwater was completely oxidized (>90% nitrification efficiency) by nitrifying bacteria to nitrite (NO2–) and nitrate (NO3–) in the dropping nitrification unit. Subsequently, the generated NO2– and NO3– were denitrified (96%–98% denitrification efficiency) by denitrifying bacteria in the cotton-based denitrification unit under anoxic conditions. Organic carbons released from the cotton presumably acted as electron donors for heterotrophic denitrification. Nitrifying and denitrifying bacteria were colonized in higher abundance in the dropping nitrification and cotton-based denitrification units, respectively. The total N removal rate and efficiency of the dropping nitrification–cotton-based denitrification reactor for 91 days were 58.1–66.9 mg-N/d and 96%–98%, respectively. Therefore, the dropping nitrification–cotton-based denitrification reactor will be an efficient, sustainable, and promising option for total N removal from NH4+-contaminated groundwater.

Performance of intermittent aeration reactor on NH4-N removal from groundwater resources

2010 ◽  
Vol 61 (12) ◽  
pp. 3061-3069 ◽  
Author(s):  
W. Khanitchaidecha ◽  
T. Nakamura ◽  
T. Sumino ◽  
F. Kazama
Keyword(s):  
Removal Rate ◽  
Groundwater Resources ◽  
Ammonium Nitrogen ◽  
Total Carbon ◽  
Intermittent Aeration ◽  
Reactor Performance ◽  
Total Carbon Content ◽  
Term Operation ◽  
N Removal ◽  
Synthetic Groundwater

To study the effect of intermittent aeration period on ammonium–nitrogen (NH4-N) removal from groundwater resources, synthetic groundwater was prepared and three reactors were operated under different conditions – “reactor A” under continuous aeration, “reactor B” under 6 h intermittent aeration, and “reactor C” under 2 h intermittent aeration. To facilitate denitrification simultaneously with nitrification, “acetate” was added as an external carbon source with step-wise increase from 0.5 to 1.5 C/N ratio, where C stands for total carbon content in the system, and N for NH4-N concentration in the synthetic groundwater. Results show that complete NH4-N removal was obtained in “reactor B” and “reactor C” at 1.3 and 1.5 C/N ratio respectively; and partial NH4-N removal in “reactor A”. These results suggest that intermittent aeration at longer interval could enhance the reactor performance on NH4-N removal in terms of efficiency and low external carbon requirement. Because of consumption of internal carbon by the process, less amount of external carbon is required. Further increase in carbon in a form of acetate (1.5 to 2.5 C/N ratios) increases removal rate (represented by reaction rate coefficient (k) of kinetic equation) as well as occurrence of free cells. It suggests that the operating condition at reactor B with 1.3 C/N ratio is more appropriate for long-term operation at a pilot-scale.

scholarly journals In Situ Water Quality Improvement Mechanism (Nitrogen Removal) by Water-Lifting Aerators in a Drinking Water Reservoir

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1051 ◽  
Author(s):  
Zizhen Zhou ◽  
Tinglin Huang ◽  
Weijin Gong ◽  
Yang Li ◽  
Yue Liu ◽  
...  
Keyword(s):  
Drinking Water ◽  
Nitrogen Removal ◽  
High Throughput Sequencing ◽  
Removal Rate ◽  
Water Reservoir ◽  
Control Area ◽  
Nitrite Accumulation ◽  
Field Scale ◽  
Drinking Water Reservoir ◽  
N Removal

A field scale experiment was performed to explore the nitrogen removal performance of the water and surface sediment in a deep canyon-shaped drinking water reservoir by operating WLAs (water-lifting aerators). Nitrogen removal performance was achieved by increasing the densities and N-removal genes (nirK and nirS) of indigenous aerobic denitrifiers. After the operation of WLAs, the total nitrogen removal rate reached 29.1 ± 0.8% in the enhanced area. Ammonia and nitrate concentrations were reduced by 72.5 ± 2.5% and 40.5 ± 2.1%, respectively. No nitrite accumulation was observed. Biolog results showed improvement of carbon metabolism and carbon source utilization of microbes in the enhanced area. Miseq high-throughput sequencing indicated that the denitrifying bacteria percentage was also higher in the enhanced area than that in the control area. Microbial communities had changed between the enhanced and control areas. Thus, nitrogen removal through enhanced indigenous aerobic denitrifiers by the operation of WLAs was feasible and successful at the field scale.

scholarly journals Upflow packed bed Anammox reactor used in two-stage deammonification of sludge digester effluent

2018 ◽  
Vol 78 (9) ◽  
pp. 1843-1851 ◽  
Author(s):  
İ. Çelen-Erdem ◽  
E. S. Kurt ◽  
B. Bozçelik ◽  
B. Çallı
Keyword(s):  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Removal Rate ◽  
Treatment Plant ◽  
Packed Bed ◽  
Municipal Wastewater Treatment ◽  
Two Stage ◽  
N Removal ◽  
Total Nitrogen Removal

Abstract The sludge digester effluent taken from a full scale municipal wastewater treatment plant (WWTP) in Istanbul, Turkey, was successfully deammonified using a laboratory scale two-stage partial nitritation (PN)/Anammox (A) process and a maximum nitrogen removal rate of 1.02 kg N/m3/d was achieved. In the PN reactor, 56.8 ± 4% of the influent NH4-N was oxidized to NO2-N and the effluent nitrate concentration was kept below 1 mg/L with 0.5–0.7 mg/L of dissolved oxygen and pH of 7.12 ± 12 at 24 ± 4°C. The effluent of the PN reactor was fed to an upflow packed bed Anammox reactor where high removal efficiency was achieved with NO2-N:NH4-N and NO3-N:NH4-N ratios of 1.32 ± 0.19:1 and 0.22 ± 0.10:1, respectively. The results show that NH4-N removal efficiency up to 98.7 ± 2.4% and total nitrogen removal of 87.7 ± 6.5% were achieved.

High nitrogen removal rate using ANAMMOX process at short hydraulic retention time

2013 ◽  
Vol 67 (5) ◽  
pp. 968-975 ◽  
Author(s):  
C. G. Casagrande ◽  
A. Kunz ◽  
M. C. De Prá ◽  
C. R. Bressan ◽  
H. M. Soares
Keyword(s):  
Nitrogen Removal ◽  
Removal Rate ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Ammonium Oxidation ◽  
High Nitrogen ◽  
Total N ◽  
Column Reactor ◽  
Anaerobic Sludge Blanket ◽  
Anammox Process

The anaerobic ammonium oxidation (ANAMMOX) is a chemolithoautotrophic process, which converts NH4+ to N2 using nitrite (NO2−) as the electron acceptor. This process has very high nitrogen removal rates (NRRs) and is an alternative to classical nitrification/denitrification wastewater treatment. In the present work, a strategy for nitrogen removal using ANAMMOX process was tested evaluating their performance when submitted to high loading rates and very short hydraulic retention times (HRTs). An up-flow ANAMMOX column reactor was inoculated with 30% biomass (v v−1) fed from 100 to 200 mg L−1 of total N (NO2−-N + NH4+-N) at 35 °C. After start-up and process stability the maximum NRR in the up-flow anaerobic sludge blanket (UASB) reactor was 18.3 g-N L−1 d−1 operated at 0.2 h of HRT. FISH (fluorescence in situ hybridization) analysis and process stoichiometry confirmed that ANAMMOX was the prevalent process for nitrogen removal during the experiments. The results point out that high NRRs can be obtained at very short HRTs using up-flow ANAMMOX column reactor configuration.

Experience from start-ups of the first ANITA Mox Plants

2013 ◽  
Vol 67 (12) ◽  
pp. 2677-2684 ◽  
Author(s):  
M. Christensson ◽  
S. Ekström ◽  
A. Andersson Chan ◽  
E. Le Vaillant ◽  
R. Lemaire
Keyword(s):  
Nitrogen Removal ◽  
Removal Rate ◽  
Treatment Plant ◽  
Ammonia Removal ◽  
Nitrogen Loading ◽  
Biofilm Reactor ◽  
Process Conditions ◽  
N2o Emissions ◽  
N Removal ◽  
Start Up

ANITA™ Mox is a new one-stage deammonification Moving-Bed Biofilm Reactor (MBBR) developed for partial nitrification to nitrite and autotrophic N-removal from N-rich effluents. This deammonification process offers many advantages such as dramatically reduced oxygen requirements, no chemical oxygen demand requirement, lower sludge production, no pre-treatment or requirement of chemicals and thereby being an energy and cost efficient nitrogen removal process. An innovative seeding strategy, the ‘BioFarm concept’, has been developed in order to decrease the start-up time of new ANITA Mox installations. New ANITA Mox installations are started with typically 3–15% of the added carriers being from the ‘BioFarm’, with already established anammox biofilm, the rest being new carriers. The first ANITA Mox plant, started up in 2010 at Sjölunda wastewater treatment plant (WWTP) in Malmö, Sweden, proved this seeding concept, reaching an ammonium removal rate of 1.2 kgN/m3 d and approximately 90% ammonia removal within 4 months from start-up. This first ANITA Mox plant is also the BioFarm used for forthcoming installations. Typical features of this first installation were low energy consumption, 1.5 kW/NH4-N-removed, low N2O emissions, <1% of the reduced nitrogen and a very stable and robust process towards variations in loads and process conditions. The second ANITA Mox plant, started up at Sundets WWTP in Växjö, Sweden, reached full capacity with more than 90% ammonia removal within 2 months from start-up. By applying a nitrogen loading strategy to the reactor that matches the capacity of the seeding carriers, more than 80% nitrogen removal could be obtained throughout the start-up period.

scholarly journals Nitrogen removal and ammonia-oxidising bacteria in a vertical flow constructed wetland treating inorganic wastewater

2011 ◽  
Vol 64 (3) ◽  
pp. 587-594 ◽  
Author(s):  
Sergio S. Domingos ◽  
Stewart Dallas ◽  
Lucy Skillman ◽  
Stephanie Felstead ◽  
Goen Ho
Keyword(s):  
Nitrogen Removal ◽  
Fragment Length Polymorphism ◽  
Removal Rate ◽  
Vertical Flow ◽  
Ammonia Monooxygenase ◽  
Specific Primers ◽  
Sediment Samples ◽  
N Removal ◽  
Monooxygenase Gene ◽  
Ammonia Oxidising Bacteria

Nitrogen removal performance and the ammonia-oxidising bacterial (AOB) community were assessed in the batch loaded 1.3 ha saturated surface vertical flow wetland at CSBP Ltd, a fertiliser and chemical manufacturer located in Kwinana, Western Australia. From September 2008 to October 2009 water quality was monitored and sediment samples collected for bacterial analyses. During the period of study the wetland received an average inflow of 1,109 m3/day with NH3-N = 40 mg/L and NO3-N = 23 mg/L. Effluent NH3-N and NO3-N were on average 31 and 25 mg/L, respectively. The overall NH3-N removal rate for the period was 1.2 g/m2/day indicating the nitrifying capacity of the wetland. The structure of the AOB community was analysed using group specific primers for the ammonia monooxygenase gene (amoA) by terminal restriction fragment length polymorphism and by clone libraries to identify key members. The majority of sequences obtained were most similar to Nitrosomonas sp. while Nitrosospira sp. was less frequent. Another two vertical flow wetlands, 0.8 ha each, were commissioned at CSBP in July 2009, since then the wetland in this study has received nitrified effluent from these two new cells.

Assessment of Inocula and N-Removal Performance of Anaerobic Ammonium Oxidation (ANAMMOX) for the Treatment of Aged Landfill Leachates

2012 ◽  
Vol 518-523 ◽  
pp. 2391-2398
Author(s):  
Yan He ◽  
Gong Ming Zhou ◽  
Min Sheng Huang ◽  
Min Tong
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Removal Rate ◽  
Granular Sludge ◽  
Nitrogen Loading ◽  
Anaerobic Granular Sludge ◽  
Landfill Leachates ◽  
N Removal ◽  
Start Up ◽  
Anammox Process

Three kinds of seeding sludge, i.e. conventional activated sludge, anaerobic granular sludge and the nitrifying activated sludge from the nitritation reactor treating aged leachates were evaluated in batch mode to screen the optimized inoculum for the rapid start-up of ANAMMOX reactor. The feasibility of the ANAMMOX process for the treatment of aged leachates was also investigated in a modified upflow anaerobic sludge blanket (UASB, 0.05m3). The batch experiments revealed that the nitrifying activated sludge from the nitritation reactor could respectively achieve the NRR (nitrogen removal rate) of 0.0365 kg N/(m3.d) and the ARR (ammonium removal rate) of 0.013 kg N/(m3.d) on day 12, which were greatly higher than those of the other two tested sludge samples. The mixture of the aforementioned nitrifying activated sludge and anaerobic granular sludge was established as an effective inoculum for the prompt start-up of ANAMMOX reactor. The maximum total nitrogen removal rate of 0.826 kg N/(m3.d) could be obtained for the treatment of “old” leachates under NLR (nitrogen loading rate) of 1.028 kg N/(m3.d). It is concluded that the N-removal performance of ANAMMOX process is still to be improved for actual engineering application to aged landfill leachates.

scholarly journals Nitrogen balance and fate in a heavily impacted watershed (Oglio River, Northern Italy): in quest of the missing sources and sinks

2012 ◽  
Vol 9 (1) ◽  
pp. 361-373 ◽  
Author(s):  
M. Bartoli ◽  
E. Racchetti ◽  
C. A. Delconte ◽  
E. Sacchi ◽  
E. Soana ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Nitrogen Removal ◽  
Nitrate Concentration ◽  
Isotope Composition ◽  
Northern Italy ◽  
N Budget ◽  
Channel Network ◽  
Total N ◽  
Crop Uptake ◽  
N Removal

Abstract. We present data from a comprehensive investigation carried out from 2007 to 2010, focussing on nitrogen pollution in the Oglio River basin (3800 km2, Po Plain, Northern Italy). Nitrogen mass balances, computed for the whole basin with 2000 and 2008 data, suggest a large N surplus in this area, over 40 000 t N yr−1, and increasing between 2000 and 2008. Calculations indicate a very large impact of animal husbandry and agricultural activities in this watershed, with livestock manure and synthetic fertilizers contributing 85% of total N inputs (about 100 000 t N yr−1) and largely exceeding crop uptake and other N losses (about 60 000 t N yr−1). Nitrogen from domestic and industrial origin is estimated as about 5800 and 7200 t N yr−1, respectively, although these loads are overestimated, as denitrification in treatment plants is not considered; nonetheless, they represent a minor term of the N budget. Annual export of nitrogen from the basin, calculated from flow data and water chemistry at the mouth of the Oglio River, is estimated at 13 000 t N yr−1, and represents a relatively small fraction of N inputs and surplus (∼12% and 34%, respectively). After considering N sinks in crop uptake, soil denitrification and volatilization, a large excess remains unaccounted (∼26 000 t N yr−1) in unknown temporary or permanent N sinks. Nitrogen removal via denitrification was evaluated in the Oglio riverbed with stable isotope techniques (δ15N and δ18O in nitrate). The downstream final segment of the river displays an enriched nitrate stable isotope composition but calculations suggest a N removal corresponding to at most 20% of the unaccounted for N amount. Denitrification was also evaluated in riverine wetlands with the isotope pairing technique. Areal rates are elevated but overall N removal is low (about 1% of the missing N amount), due to small wetland surfaces and limited lateral connectivity. The secondary drainage channel network has a much higher potential for nitrogen removal via denitrification, due to its great linear development, estimated in over 12 500 km, and its capillary distribution in the watershed. In particular, we estimated a maximum N loss up to 8500 t N yr−1, which represents up to 33% of the unaccounted for N amount in the basin. Overall, denitrification in surface aquatic habitats within this basin can be responsible for the permanent removal of about 12 000 t N yr−1; but the fate of some 14 000 t remains unknown. Available data on nitrate concentration in wells suggest that in the central part of the watershed groundwater accumulates nitrogen. Simultaneously, we provide evidences that part of the stored nitrate can be substantially recycled via springs and can pollute surface waters via river-groundwater interactions. This probably explains the ten fold increase of nitrate concentration in a reach of the Oglio River where no point pollutions sources are present.

SUSTAINABLE NITROGEN REMOVAL USING APPROPRIATE TECHNOLOGIES

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Krishnanand Maillacheruvu ◽  
Derek Hartmann
Keyword(s):  
Rate Constant ◽  
Nitrogen Removal ◽  
Removal Rate ◽  
Low Cost ◽  
C:N Ratio ◽  
Treatment Plant ◽  
Agricultural Runoff ◽  
Point Sources ◽  
Nitrogen And Phosphorus ◽  
N Removal

Nitrogen and phosphorus are two major pollutants that lead to eutrophication, adversely impact ecosystems, and lead to degradation of water quality, which impacts human health and sustainability. Pollution from point sources like wastewater and industry discharge is easier to control than non-point source pollution due to agricultural runoff and related activities. The USEPA is considering more strict standards for nitrogen and phosphorus discharge from point sources. The objective of this study was to use an appropriate low-cost wastewater technology to demonstrate removal of nitrogen from wastewater discharge using rotating biological contactors (RBCs) using different C:N ratios. The first-order nitrogen removal rate constant was found to be about 3.88 day-1 in experimental reactor systems, using RBC media from a local wastewater treatment plant (Greater Peoria Sanitary District). Phase I experiments, at C:N ratio of 2:1, with nitrogen removal rates of 60% in a single flow-through system. Phase II experiments for the limited carbon availability condition showed that the removal rate constant reduced by 30% and N-removal efficiency dropped to around 48%. Modeling showed that even under these conditions, multiple bioreactors operated in series could help achieve design treatment goals. The system achieved stability within a week of operation. Economics and sustainability issues are analyzed to determine if the process developed in this research is scalable to pilot-and full-scale conditions.

Does influent COD/N ratio affect nitrogen removal and N2O emission in a novel biochar-sludge amended soil wastewater infiltration system (SWIS)?

2018 ◽  
Vol 78 (2) ◽  
pp. 347-357 ◽  
Author(s):  
Fanping Zheng ◽  
Chaoquan Tan ◽  
Wanyuan Hou ◽  
Linli Huang ◽  
Jing Pan ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Emission Rate ◽  
N2o Emission ◽  
Nitrifying Bacteria ◽  
N2o Emissions ◽  
Intermittent Aeration ◽  
Ratio Increase ◽  
Removal Rates ◽  
N Removal ◽  
Amended Soil

Abstract Nitrogen removal and N2O emission of a biochar-sludge amended soil wastewater infiltration system (SWIS) with/without intermittent aeration under different influent COD/N ratios was investigated. Nitrogen removal and N2O emission were affected by influent COD/N ratio. Under a COD/N ratio between 1:1 and 15:1, average chemical oxygen demand (COD), NH4+-N and total nitrogen (TN) removal rates decreased with COD/N ratio increase in non-aerated SWISs amended with/without biochar-sludge; an increasing COD/N ratio hardly affected COD and NH4+-N removal in a biochar-sludge amended SWIS with intermittent aeration; the N2O emission rate decreased with COD/N ratio increase in the studied SWISs. The biochar-sludge amended SWIS with intermittent aeration achieved high COD (92.2%), NH4+-N (96.8%), and TN (92.7%) removal rates and a low N2O emission rate (10.6 mg/(m2 d)) under a COD/N ratio of 15:1, which was higher than those in non-aerated SWISs amended with/without biochar-sludge. Combining the biochar-sludge amended SWIS with intermittent aeration enhanced the number of nitrifying bacteria, denitrifying bacteria, nitrate reductase activities, nitrite reductase activities, and improved the abundance of nitrogen removal functional genes under a high influent COD/N ratio. The results suggested that the joint use of intermittent aeration and biochar-sludge in a SWIS could be an effective and appropriate strategy for improving nitrogen removal and reducing N2O emissions in treating high COD/N ratio wastewater.

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