Nitrous oxide emission during nitrification and denitrification in a full-scale night soil treatment plant

1996 ◽  
Vol 34 (1-2) ◽  
pp. 277-284 ◽  
Author(s):  
Hiroki Itokawa ◽  
Keisuke Hanaki ◽  
Tomonori Matsuo
Keyword(s):  
Nitrous Oxide ◽  
Treatment Plant ◽  
Full Scale ◽  
Soil Treatment ◽  
Aeration Tank ◽  
N2o Emissions ◽  
N2o Production ◽  
Mixed Liquor ◽  
Significant Difference ◽  
Nitrification And Denitrification

Nitrous oxide (N2O) emissions from nitrification-denitrification processes in a full-scale night soil treatment plant were measured, and patterns and control of the N2O production were investigated. Estimated N2O emissions ranged from 4.4 to 1,190 gN/(m3 of influent), corresponding to a conversion ratio of influent nitrogen to N2O-N of 0.24-55%. N2O was produced in the intermittent aeration tank (IAT) where nitrification and denitrification were carried out alternately. The produced N2O was either stripped out to the off-gas or remained in the effluent in dissolved form. The former accounted for more than 99.5% of the total emissions. The latter flowed into the following anoxic tank, where 60-98% of N2O was reduced. A significant difference in the extent of N2O supersaturation in mixed liquor of IAT was observed between the cases of high and low N2O emissions. In IAT, N2O tended to be produced discretely either in aerobic or in anoxic phases. It seemed that the completeness of nitrification and denitrification in IAT, indicated from a mass balance between NH4-N and NO3-N and from NO2-N accumulation in mixed liquor of IAT, was one of the important factors affecting the N2O production. This completeness was decided by the time ratio of aerobic and anoxic phases. External addition of methanol to IAT seemed to reduce N2O emissions.

scholarly journals Comparison of methods for nitrous oxide emission estimation in full-scale activated sludge

2021 ◽  
Vol 83 (3) ◽  
pp. 641-651
Author(s):  
Shanna Myers ◽  
Anna Mikola ◽  
Kati Blomberg ◽  
Anna Kuokkanen ◽  
Diego Rosso
Keyword(s):  
Nitrous Oxide ◽  
Liquid Phase ◽  
Treatment Plant ◽  
N2o Emission ◽  
Full Scale ◽  
Gas Transfer ◽  
N2o Emissions ◽  
Static Correction ◽  
Emission Estimation ◽  
Novel Method

Abstract Nitrous oxide (N2O) gas transfer was studied in a full-scale process to correlate liquid phase N2O concentrations with gas phase N2O emissions and compare methods of determining the volumetric mass transfer coefficient, KLa. Off-gas and liquid phase monitoring were conducted at the Viikinmäki wastewater treatment plant (WWTP) over a two-week period using a novel method for simultaneous measurement of dissolved and off-gas N2O and O2 from the same location. KLa was calculated with three methods: empirically, based on aeration superficial velocity, from experimentally determined O2 KLa, and using a static value of best fit. The findings of this study indicated trends in local emitted N2O consistently matched trends in local dissolved N2O, but the magnitude of N2O emissions could not be accurately estimated without correction. After applying a static correction factor, the O2 method, using experimentally determined O2 KLa, provided the best N2O emission estimation over the data collection period. N2O emissions estimated using the O2 method had a root mean square error (RMSE) of 70.5 compared against measured concentrations ranging from 3 to 1,913 ppm and a maximum 28% error. The KLa value, and therefore the method of KLa determination, had a significant impact on estimated emissions.

scholarly journals CONTROLLING FACTORS OF NITROUS OXIDE EMISSIONS FROM A CONVENTIONAL ACTIVATED SLUDGE WASTEWATER TREATMENT PLANT

Engevista ◽  
2015 ◽  
Vol 17 (3) ◽  
pp. 375 ◽  
Author(s):  
Renato Pereira Ribeiro ◽  
Jaime Lopes da Mota Oliveira ◽  
Débora Cynamon Kligerman ◽  
Renata Barbosa Alvim ◽  
Samara Almeida Andrade ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Nitrous Oxide Emissions ◽  
Aeration Tank ◽  
N2o Emissions ◽  
Air Stripping ◽  
Conventional Activated Sludge

Nitrous oxide emissions were determined in three campaigns in the aeration tank of a full scale conventional activated sludge wastewater treatment plant. During these experiments, the carbonaceous organic matter (BOD and COD) removal was high and rather constant (97-98% and 93-96%). The results indicate that the concentration of total nitrogen in the influent wastewater, especially NH4+, and the aeration flow rate are key controlling factor of N2O emissions from the aeration tank. Nitrification was the major source of N2O, suggested by the behavior of DO concentrations, NO3-/NH4+ ratio and pH values along the six interlinked zones of the aeration tank. Excessive air flow intensified N2O transfer from the liquor to the atmosphere by air stripping.

Evaluating the treatment performance of a full scale Activated Sludge Plant in Islamabad, Pakistan

2012 ◽  
Vol 7 (1) ◽  
Author(s):  
S. S. Fatima ◽  
S. Jamal Khan
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Suspended Solids ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Full Scale ◽  
Operational Parameter ◽  
Mixed Liquor ◽  
Treatment Performance

In this study, the performance of wastewater treatment plant located at sector I-9 Islamabad, Pakistan, was evaluated. This full scale domestic wastewater treatment plant is based on conventional activated sludge process. The parameters which were monitored regularly included total suspended solids (TSS), mixed liquor suspended solids (MLSS), mixed liquor volatile suspended solids (MLVSS), biological oxygen demand (BOD), and chemical oxygen demand (COD). It was found that the biological degradation efficiency of the plant was below the desired levels in terms of COD and BOD. Also the plant operators were not maintaining consistent sludge retention time (SRT). Abrupt discharge of MLSS through the Surplus Activated sludge (SAS) pump was the main reason for the low MLSS in the aeration tank and consequently low treatment performance. In this study the SRT was optimized based on desired MLSS concentration between 3,000–3,500 mg/L and required performance in terms of BOD, COD and TSS. This study revealed that SRT is a very important operational parameter and its knowledge and correct implementation by the plant operators should be mandatory.

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 Nitrogen and oxygen availabilities control water column nitrous oxide production during seasonal anoxia in the Chesapeake Bay

2018 ◽  
Vol 15 (20) ◽  
pp. 6127-6138 ◽  
Author(s):  
Qixing Ji ◽  
Claudia Frey ◽  
Xin Sun ◽  
Melanie Jackson ◽  
Yea-Shine Lee ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Chesapeake Bay ◽  
Water Column ◽  
N2o Emissions ◽  
N2o Production ◽  
Isotope Tracer ◽  
Relative Contribution ◽  
Environmental Controls ◽  
Long Run ◽  
Nitrate And Nitrite

Abstract. Nitrous oxide (N2O) is a greenhouse gas and an ozone depletion agent. Estuaries that are subject to seasonal anoxia are generally regarded as N2O sources. However, insufficient understanding of the environmental controls on N2O production results in large uncertainty about the estuarine contribution to the global N2O budget. Incubation experiments with nitrogen stable isotope tracer were used to investigate the geochemical factors controlling N2O production from denitrification in the Chesapeake Bay, the largest estuary in North America. The highest potential rates of water column N2O production via denitrification (7.5±1.2 nmol-N L−1 h−1) were detected during summer anoxia, during which oxidized nitrogen species (nitrate and nitrite) were absent from the water column. At the top of the anoxic layer, N2O production from denitrification was stimulated by addition of nitrate and nitrite. The relative contribution of nitrate and nitrite to N2O production was positively correlated with the ratio of nitrate to nitrite concentrations. Increased oxygen availability, up to 7 µmol L−1 oxygen, inhibited both N2O production and the reduction of nitrate to nitrite. In spring, high oxygen and low abundance of denitrifying microbes resulted in undetectable N2O production from denitrification. Thus, decreasing the nitrogen input into the Chesapeake Bay has two potential impacts on the N2O production: a lower availability of nitrogen substrates may mitigate short-term N2O emissions during summer anoxia; and, in the long-run (timescale of years), eutrophication will be alleviated and subsequent reoxygenation of the bay will further inhibit N2O production.

scholarly journals Spatial and temporal variability of nitrous oxide emissions in a mixed farming landscape of Denmark

2012 ◽  
Vol 9 (8) ◽  
pp. 2989-3002 ◽  
Author(s):  
K. Schelde ◽  
P. Cellier ◽  
T. Bertolini ◽  
T. Dalgaard ◽  
T. Weidinger ◽  
...  
Keyword(s):  
Land Use ◽  
Nitrous Oxide ◽  
Agricultural Land ◽  
Nitrous Oxide Emissions ◽  
Soil Conditions ◽  
Spatial And Temporal Variability ◽  
N2o Emissions ◽  
N2o Production ◽  
Mixed Farming ◽  
N2o Fluxes

Abstract. Nitrous oxide (N2O) emissions from agricultural land are variable at the landscape scale due to variability in land use, management, soil type, and topography. A field experiment was carried out in a typical mixed farming landscape in Denmark, to investigate the main drivers of variations in N2O emissions, measured using static chambers. Measurements were made over a period of 20 months, and sampling was intensified during two weeks in spring 2009 when chambers were installed at ten locations or fields to cover different crops and topography and slurry was applied to three of the fields. N2O emissions during spring 2009 were relatively low, with maximum values below 20 ng N m−2 s−1. This applied to all land use types including winter grain crops, grasslands, meadows, and wetlands. Slurry application to wheat fields resulted in short-lived two-fold increases in emissions. The moderate N2O fluxes and their moderate response to slurry application were attributed to dry soil conditions due to the absence of rain during the four previous weeks. Cumulative annual emissions from two arable fields that were both fertilized with mineral fertilizer and manure were large (17 kg N2O-N ha−1 yr−1 and 5.5 kg N2O-N ha−1 yr−1) during the previous year when soil water conditions were favourable for N2O production during the first month following fertilizer application. Our findings confirm the importance of weather conditions as well as nitrogen management on N2O fluxes.

Recycling of water treatment sludges in municipal wastewater treatment plants – a practical example

2008 ◽  
Vol 3 (1) ◽  
Author(s):  
K. Klinksieg ◽  
T. Dockhorn ◽  
N. Dichtl
Keyword(s):  
Wastewater Treatment ◽  
Water Treatment ◽  
Wastewater Treatment Plant ◽  
Iron Hydroxide ◽  
Settling Tank ◽  
Treatment Plant ◽  
Full Scale ◽  
Aeration Tank ◽  
Second Phase ◽  
Precipitation Efficiency

Full-scale and lab-scale research experiments were conducted to determine the phosphorous precipitation efficiency of iron hydroxide sludge from drinking water treatment. During full-scale investigations at a wastewater treatment plant, ferric sludge was added to the inflow of the primary settling tank in a first experimental phase and to the inflow of the aeration tank in a second phase. In the outflow of the mechanical stage and in the outflow of the biological stage, a reduction of the PO4-P concentrations could be observed. The concentration of COD, the SVI and the filament abundance were not changed significantly by adding the ferric sludge to the wastewater treatment plant. In lab tests, improved precipitation efficiency of the ferric sludge could be achieved by using anaerobic conditions and acid pulping. The research showed that the wastewater treatment process can benefit from the reuse of ferric sludge from drinking waterworks and that this also presents an inexpensive recycling option for these sludges.

Cost optimisation and minimisation of the environmental impact through life cycle analysis of the waste water treatment plant of Bree (Belgium)

2011 ◽  
Vol 63 (1) ◽  
pp. 164-170 ◽  
Author(s):  
K. De Gussem ◽  
T. Wambecq ◽  
J. Roels ◽  
A. Fenu ◽  
G. De Gueldre ◽  
...  
Keyword(s):  
Waste Water ◽  
Life Cycle ◽  
Environmental Impact ◽  
Waste Water Treatment ◽  
Treatment Plant ◽  
Full Scale ◽  
Waste Water Treatment Plant ◽  
Aeration Tank ◽  
Environmental Footprint ◽  
Recirculation Flow

An ASM2da model of the full-scale waste water plant of Bree (Belgium) has been made. It showed very good correlation with reference operational data. This basic model has been extended to include an accurate calculation of environmental footprint and operational costs (energy consumption, dosing of chemicals and sludge treatment). Two optimisation strategies were compared: lowest cost meeting the effluent consent versus lowest environmental footprint. Six optimisation scenarios have been studied, namely (i) implementation of an online control system based on ammonium and nitrate sensors, (ii) implementation of a control on MLSS concentration, (iii) evaluation of internal recirculation flow, (iv) oxygen set point, (v) installation of mixing in the aeration tank, and (vi) evaluation of nitrate setpoint for post denitrification. Both an environmental impact or Life Cycle Assessment (LCA) based approach for optimisation are able to significantly lower the cost and environmental footprint. However, the LCA approach has some advantages over cost minimisation of an existing full-scale plant. LCA tends to chose control settings that are more logic: it results in a safer operation of the plant with less risks regarding the consents. It results in a better effluent at a slightly increased cost.

Sources of nitrous oxide from 15N-labelled animal urine and urea fertiliser with and without a nitrification inhibitor, dicyandiamide (DCD)

Soil Research ◽  
2008 ◽  
Vol 46 (1) ◽  
pp. 76 ◽  
Author(s):  
H. J. Di ◽  
K. C. Cameron
Keyword(s):  
Nitrous Oxide ◽  
Dairy Cow ◽  
Priming Effect ◽  
Nitrification Inhibitor ◽  
Major Effect ◽  
N2o Emissions ◽  
Soil N ◽  
Cow Urine ◽  
Nitrification And Denitrification ◽  
N Pool

A field lysimeter study was conducted to determine the sources of N2O emitted following the application of dairy cow urine and urea fertiliser labelled with 15N, with and without a nitrification inhibitor, dicyandiamide (DCD). The results show that the application of cow urine at 1000 kg N/ha significantly increased N2O emissions above that from urea applied alone at 25 kg N/ha. The application of urine seemed to have a priming effect, increasing N2O emissions from the soil N pool. Treating the soil with DCD significantly (P < 0.05) decreased N2O emissions from the urine-applied treatment by 72%. The percentage of N2O-N derived from the applied N was 53.1% in the urine-applied treatment and this was reduced to 29.9% when DCD was applied. On average, about 43% of the N2O emitted in the urine-applied treatments was from nitrification. The application of DCD did not have a major effect on the relative contributions of nitrification and denitrification to N2O emissions in the urine treatments. This indicates that the DCD nitrification inhibitor decreased the contributions to N2O emissions from both nitrification and denitrification.

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