Nitrogen removal and nitrous oxide emissions in woodchips biofilters treating agricultural drainage waters

2020 ◽  
Author(s):  
Joachim Audet ◽  
Dominik Zak ◽  
Carl Christian Hoffmann
Keyword(s):  
Gas Chromatography ◽  
Nitrous Oxide ◽  
Nitrogen Removal ◽  
Drainage Water ◽  
Agricultural Landscapes ◽  
Nitrous Oxide Emissions ◽  
Temperate Climate ◽  
Closed Chamber ◽  
Total N ◽  
N Removal

<p>Eutrophication of aquatic ecosystems provoked by excess nitrogen (N) concentration is still a major concern worldwide with severe consequences such as hypoxia, biodiversity loss, and degradation of drinking water quality. To face these challenges, a novel N mitigation measure has emerged in the last decades consisting of biofilters made of woodchips. Drainage water from agricultural areas infiltrate through a layer of woodchips before it discharges to an aquatic recipient such as a ditch or a stream. The goal with this technique is to provide optimal conditions for denitrification i.e. an easy degradable carbon source (the woodchips) and an anaerobic environment. There is, however, some concerns regarding the emissions of the greenhouse gas nitrous oxide (N<sub>2</sub>O) which can be a by-product of denitrification.</p><p>Here, we present results on N removal and N<sub>2</sub>O emissions from 9 biofilters differing in age (1–8 years) and representing a total of 18 years of monitoring. The biofilters were all located in agricultural catchments in Denmark (temperate climate conditions). Nitrogen removal in the biofilters was estimated using a mass balance approach measuring N species dissolved in the water (total N, nitrate, nitrite, ammonium) using time proportional automated samplers placed at inlet and outlet of the biofilters. Nitrous oxide emissions were measured every third week both as gaseous form at the surface of the biofilters (closed chamber technique and gas chromatography) and in dissolved form in the water phase at inlet and outlet of the biofilters (headspace technique and gas chromatography). We take advantage of this unique dataset to identify the factors enabling to maximize N removal while minimizing N<sub>2</sub>O emissions. Furthermore, we make a first assessment of the potential impact of the increasing number of biofilters on N<sub>2</sub>O emissions in agricultural landscapes.</p>

scholarly journals Biochar and urease inhibitor mitigate NH3 and N2O emissions and improve wheat yield in a urea fertilized alkaline soil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Khadim Dawar ◽  
Shah Fahad ◽  
M. M. R. Jahangir ◽  
Iqbal Munir ◽  
Syed Sartaj Alam ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Grain Yield ◽  
Block Design ◽  
N Uptake ◽  
Nitrous Oxide Emissions ◽  
N2o Emissions ◽  
Urease Inhibitor ◽  
Alkaline Soil ◽  
Total N ◽  
N Assimilation

AbstractIn this study, we explored the role of biochar (BC) and/or urease inhibitor (UI) in mitigating ammonia (NH3) and nitrous oxide (N2O) discharge from urea fertilized wheat cultivated fields in Pakistan (34.01°N, 71.71°E). The experiment included five treatments [control, urea (150 kg N ha−1), BC (10 Mg ha−1), urea + BC and urea + BC + UI (1 L ton−1)], which were all repeated four times and were carried out in a randomized complete block design. Urea supplementation along with BC and BC + UI reduced soil NH3 emissions by 27% and 69%, respectively, compared to sole urea application. Nitrous oxide emissions from urea fertilized plots were also reduced by 24% and 53% applying BC and BC + UI, respectively, compared to urea alone. Application of BC with urea improved the grain yield, shoot biomass, and total N uptake of wheat by 13%, 24%, and 12%, respectively, compared to urea alone. Moreover, UI further promoted biomass and grain yield, and N assimilation in wheat by 38%, 22% and 27%, respectively, over sole urea application. In conclusion, application of BC and/or UI can mitigate NH3 and N2O emissions from urea fertilized soil, improve N use efficiency (NUE) and overall crop productivity.

scholarly journals Denitrifying pathways dominate nitrous oxide emissions from managed grassland during drought and rewetting

2021 ◽  
Vol 7 (6) ◽  
pp. eabb7118
Author(s):  
E. Harris ◽  
E. Diaz-Pines ◽  
E. Stoll ◽  
M. Schloter ◽  
S. Schulz ◽  
...  
Keyword(s):  
Growth Rate ◽  
Nitrous Oxide ◽  
N Fertilization ◽  
High Variability ◽  
Nitrous Oxide Emissions ◽  
Severe Drought ◽  
Total N ◽  
The Past ◽  
Precipitation Changes ◽  
Isotopic Measurements

Nitrous oxide is a powerful greenhouse gas whose atmospheric growth rate has accelerated over the past decade. Most anthropogenic N2O emissions result from soil N fertilization, which is converted to N2O via oxic nitrification and anoxic denitrification pathways. Drought-affected soils are expected to be well oxygenated; however, using high-resolution isotopic measurements, we found that denitrifying pathways dominated N2O emissions during a severe drought applied to managed grassland. This was due to a reversible, drought-induced enrichment in nitrogen-bearing organic matter on soil microaggregates and suggested a strong role for chemo- or codenitrification. Throughout rewetting, denitrification dominated emissions, despite high variability in fluxes. Total N2O flux and denitrification contribution were significantly higher during rewetting than for control plots at the same soil moisture range. The observed feedbacks between precipitation changes induced by climate change and N2O emission pathways are sufficient to account for the accelerating N2O growth rate observed over the past decade.

scholarly journals Pineapple Residue Ash Reduces Carbon Dioxide and Nitrous Oxide Emissions in Pineapple Cultivation on Tropical Peat Soils at Saratok, Malaysia

2021 ◽  
Vol 13 (3) ◽  
pp. 1014
Author(s):  
Liza Nuriati Lim Kim Choo ◽  
Osumanu Haruna Ahmed ◽  
Nik Muhamad Nik Majid ◽  
Zakry Fitri Abd Aziz
Keyword(s):  
Carbon Dioxide ◽  
Nitrous Oxide ◽  
Peat Soil ◽  
Nitrous Oxide Emissions ◽  
N2o Emissions ◽  
Peat Soils ◽  
Closed Chamber ◽  
Npk Fertilizers ◽  
Npk Fertilizer ◽  
Carbon Dioxide Co2

Burning pineapple residues on peat soils before pineapple replanting raises concerns on hazards of peat fires. A study was conducted to determine whether ash produced from pineapple residues could be used to minimize carbon dioxide (CO2) and nitrous oxide (N2O) emissions in cultivated tropical peatlands. The effects of pineapple residue ash fertilization on CO2 and N2O emissions from a peat soil grown with pineapple were determined using closed chamber method with the following treatments: (i) 25, 50, 70, and 100% of the suggested rate of pineapple residue ash + NPK fertilizer, (ii) NPK fertilizer, and (iii) peat soil only. Soils treated with pineapple residue ash (25%) decreased CO2 and N2O emissions relative to soils without ash due to adsorption of organic compounds, ammonium, and nitrate ions onto the charged surface of ash through hydrogen bonding. The ability of the ash to maintain higher soil pH during pineapple growth primarily contributed to low CO2 and N2O emissions. Co-application of pineapple residue ash and compound NPK fertilizer also improves soil ammonium and nitrate availability, and fruit quality of pineapples. Compound NPK fertilizers can be amended with pineapple residue ash to minimize CO2 and N2O emissions without reducing peat soil and pineapple productivity.

Does intermittent aeration and/or an influent distributary affect nitrogen removal and nitrous oxide emission of an ecological soil wastewater infiltration system?

2019 ◽  
Vol 79 (7) ◽  
pp. 1417-1425 ◽  
Author(s):  
Yue Zhao ◽  
Zhiyu Zhang ◽  
Ziqi Li ◽  
Shiyao Wang ◽  
Chaoquan Tan ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Nitrogen Removal ◽  
Emission Rate ◽  
N2o Emission ◽  
Functional Genes ◽  
Intermittent Aeration ◽  
Anaerobic Conditions ◽  
N Removal ◽  
The Matrix ◽  
Removal Efficiencies

Abstract The effect of intermittent aeration and an influent distributary on NH4+-N removal, total nitrogen (TN) removal, nitrous oxide (N2O) emission and the abundances of nitrogen removal and N2O emission functional genes in four types of ecological soil wastewater infiltration systems (ESWISs) (which were conventional ESWIS 1 (operated without aeration and influent distributary), ESWIS 2 (operated with intermittent aeration), ESWIS 3 (operated with influent distributary) and ESWIS 4 (operated with intermittent aeration and influent distributary)) were studied. Intermittent aeration in ESWIS 2 and 4 created aerobic conditions above 50 cm depth of the matrix and anoxic or anaerobic conditions in the lower matrix (below 80 cm depth). ESWIS 4 improved NH4+-N (to 90.1%) and TN (to 87.8%) removal efficiencies and increased the abundances of eight nitrogen removal and N2O emission functional genes (amoA, nxrA, narG, napA, nirS, nirK, qnorB and nosZ) in contrast with other ESWISs. The combination of intermittent aeration and influent distributary achieved the lowest N2O emission rate of 34.7 mg/(m2 d) in ESWIS 4. Intermittent aeration combined with influent distributary was recommended for ESWISs to enhance nitrogen removal and reduce N2O emission.

scholarly journals Contribution of the cotton irrigation network to farm nitrous oxide emissions

Soil Research ◽  
2016 ◽  
Vol 54 (5) ◽  
pp. 651 ◽  
Author(s):  
B. C. T. Macdonald ◽  
A. Nadelko ◽  
Y. Chang ◽  
M. Glover ◽  
S. Warneke
Keyword(s):  
Nitrous Oxide ◽  
Surface Area ◽  
Land Surface ◽  
Irrigation System ◽  
Minor Component ◽  
Nitrous Oxide Emissions ◽  
N2o Emissions ◽  
Deep Drainage ◽  
Total N ◽  
Irrigation Network

Nitrous oxide (N2O) is a potent greenhouse gas, and agriculture is the dominant source of N2O-N emissions. The Australian cotton industry requires high inputs of N to maintain high lint quality and yields; however, over-fertilisation with N is symptomatic of the industry. Up to 3.5% of N fertiliser applied is lost directly from cotton fields as N2O gas. Excess N may also be lost via erosion, deep-drainage, leaching and runoff, and may subsequently form indirect N2O emissions. The estimate by the Intergovernmental Panel on Climate Change (IPCC) suggests that 0.0025kg N2O-N is produced indirectly from groundwater and surface drainage for each kg N lost via runoff and leaching, although this estimate carries a large degree of uncertainty. This study is the first to address the lack of indirect N2O emission data from irrigated cotton-farming systems. Indirect emissions were determined from total N concentrations in irrigation runoff by using the IPCC emission factor and from measurements of dissolved N2O during the first four irrigations (October–December 2013). Total indirect N2O emissions from the surface of the irrigation network over 3 months when estimated by the dissolved-N2O method were 0.503±0.339kgha–1. By contrast, N2O emissions estimated by the IPCC methodology were 0.843±0.022kgha–1 irrigation surface area. Over the same period of measurement, direct land-surface emissions were 1.44kgN2O-Nha–1 field. Despite relatively high emissions per surface area, the irrigation network is only a minor component of the total farm area, and indirect emissions from the irrigation system contribute ~2.4–4% of the total N2O emissions and <0.02% of the applied N fertiliser.

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.

scholarly journals Integrated Low-Energy and Low Carbon Shortcut Nitrogen removal with Biological Phosphorus Removal for Sustainable Mainstream Wastewater Treatment

2019 ◽  
Author(s):  
Paul Roots ◽  
Fabrizio Sabba ◽  
Alex F. Rosenthal ◽  
Yubo Wang ◽  
Quan Yuan ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Phosphorus Removal ◽  
Inorganic Nitrogen ◽  
Ex Situ ◽  
Nitrous Oxide Emissions ◽  
Biological Phosphorus Removal ◽  
Removal Rates ◽  
Total N ◽  
Biological Phosphorus ◽  
P Removal

AbstractWhile enhanced biological phosphorus removal (EBPR) is widely utilized for phosphorus (P) removal from wastewater, understanding of efficient process alternatives that allow combined biological P removal and shortcut nitrogen (N) removal, such as nitritation-denitritation, is limited. Here, we demonstrate efficient and reliable combined total N, P, and chemical oxygen demand removal (70%, 83%, and 81%, respectively) in a sequencing batch reactor (SBR) treating real mainstream wastewater (primary effluent) at 20°C. Anaerobic – aerobic cycling (with intermittent oxic/anoxic periods during aeration) was used to achieve consistent removal rates, nitrite oxidizing organism (NOO) suppression, and high effluent quality. Importantly, high resolution process monitoring coupled to ex situ batch activity assays demonstrated that robust biological P removal was coupled to energy and carbon efficient nitritation-denitritation, not simultaneous nitrification-denitrification, for the last >400 days of 531 total days of operation. Nitrous oxide emissions of 2.2% relative to the influent TKN (or 5.2% relative to total inorganic nitrogen removal) were similar to those measured in other shortcut N bioprocesses. No exogenous chemicals were needed to achieve consistent process stability and high removal rates in the face of frequent wet weather flows and highly variable influent concentrations. Process modeling reproduced the performance observed in the SBR and confirmed that nitrite drawdown via denitritation contributed to suppression of NOO activity.

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 (&gt;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.

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