Long-term nitrogen compound removal trends of a hybrid subsurface constructed wetland treating milking parlor wastewater throughout its 7 years of operation

2015 ◽  
Vol 73 (5) ◽  
pp. 1018-1024 ◽  
Author(s):  
J. Harada ◽  
T. Inoue ◽  
K. Kato ◽  
H. Izumoto ◽  
X. Zhang ◽  
...  
Keyword(s):  
Constructed Wetland ◽  
Nitrogen Compound ◽  
Total Carbon ◽  
Removal Rates ◽  
N Removal ◽  
Transformation Mechanisms ◽  
Water Recirculation ◽  
Second Year ◽  
Northern Japan

This study evaluated the nitrogen compound removal efficiency of a hybrid subsurface constructed wetland, which began treating milking parlor wastewater in Hokkaido, northern Japan, in 2006. The wetland's overall removal rates of total nitrogen (TN) and ammonium (NH4+-N) improved after the second year of operation, and its rate of organic nitrogen (Org-N) removal was stable at 90% efficiency. Only nitrate (NO3−-N) levels were increased following the treatment. Despite increased NO3−-N (maximum of 3 mg-N/L) levels, TN removal rates were only slightly affected. Removal rates of TN and Org-N were highest in the first vertical bed. NH4+-N removal rates were highest in the second vertical bed, presumably due to water recirculation and pH adjustment. Concentrations of NO3−-N appeared when total carbon (TC) levels were low, which suggests that low TC prevented complete denitrification in the second vertical bed and the final horizontal bed. In practice, the beds removed more nitrogen than the amount theoretically removed by denitrification, as calculated by the amount of carbon removed from the system. This carbon-nitrogen imbalance may be due to other nitrogen transformation mechanisms, which require less carbon.

scholarly journals Assessing METland® Design and Performance Through LCA: Techno-Environmental Study With Multifunctional Unit Perspective

2021 ◽  
Vol 12 ◽  
Author(s):  
Lorena Peñacoba-Antona ◽  
Jorge Senán-Salinas ◽  
Arantxa Aguirre-Sierra ◽  
Pedro Letón ◽  
Juan José Salas ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Constructed Wetland ◽  
Rural Areas ◽  
High Efficiency ◽  
Organic Pollutant ◽  
Environmentally Friendly ◽  
Environmental Study ◽  
External Energy ◽  
Removal Rates ◽  
N Removal

Conventional wastewater treatment technologies are costly and energy demanding; such issues are especially remarkable when small communities have to clean up their pollutants. In response to these requirements, a new variety of nature-based solution, so-called METland®, has been recently develop by using concepts from Microbial Electrochemical Technologies (MET) to outperform classical constructed wetland regarding wastewater treatment. Thus, the current study evaluates two operation modes (aerobic and aerobic–anoxic) of a full-scale METland®, including a Life Cycle Assessment (LCA) conducted under a Net Environmental Balance perspective. Moreover, a combined technical and environmental analysis using a Net Eutrophication Balance (NEuB) focus concluded that the downflow (aerobic) mode achieved the highest removal rates for both organic pollutant and nitrogen, and it was revealed as the most environmentally friendly design. Actually, aerobic configuration outperformed anaero/aero-mixed mode in a fold-range from 9 to 30%. LCA was indeed recalculated under diverse Functional Units (FU) to determine the influence of each FU in the impacts. Furthermore, in comparison with constructed wetland, METland® showed a remarkable increase in wastewater treatment capacity per surface area (0.6 m2/pe) without using external energy. Specifically, these results suggest that aerobic–anoxic configuration could be more environmentally friendly under specific situations where high N removal is required. The removal rates achieved demonstrated a robust adaptation to influent variations, revealing a removal average of 92% of Biology Oxygen Demand (BOD), 90% of Total Suspended Solids (TSS), 40% of total nitrogen (TN), and 30% of total phosphorus (TP). Moreover, regarding the global warming category, the overall impact was 75% lower compared to other conventional treatments like activated sludge. In conclusion, the LCA revealed that METland® appears as ideal solution for rural areas, considering the low energy requirements and high efficiency to remove organic pollutants, nitrogen, and phosphates from urban wastewater.

COD and NH4-N Removal in Two-Stage Batch-Flow Constructed Wetland

2013 ◽  
Vol 448-453 ◽  
pp. 604-607 ◽  
Author(s):  
Hong Jie Sun ◽  
Xin Nan Deng ◽  
Rui Chen
Keyword(s):  
Constructed Wetland ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Pilot Scale ◽  
Ammonia Nitrogen ◽  
Two Stage ◽  
Removal Rates ◽  
N Removal ◽  
Domestic Wastewater Treatment

Research was conducted on pilot-scale, two-stage batch-flow constructed wetland systems for domestic wastewater treatment. Synthetic domestic wastewater was treated in a pre-acidification reactor with a hydraulic retention time (HRT) of 3 hours and the average removal rate of chemical oxygen demand (COD) and ammonia-nitrogen (NH4-N) reached 30% and 13.6%, respectively. The first-stage constructed wetland operated with up-flow and batch feed and drain. One cycle was 12h, including 6h feed and 6h drain. With HRT of 3 days, the effluent COD concentrations fluctuated from 32.5 mg/L to 103.4 mg/L, removal rates varied from 60% to 88%; effluent NH4-N concentrations were in the range of 4.8 mg/L to 10.8 mg/L, removal rates varied from 50% to 70%. The second-stage constructed wetland operated with down-flow, which one cycle was 24h, including 12h feed and 12h drain. With HRT of 1 day, effluent COD concentrations varied from 15.7 mg/L to 48.7 mg/L, removal averaged 53.2%; effluent NH4-N concentrations ranged from 0 mg/L to 0.4 mg/L, average removal exceeded 99%. The spatial variation of COD and NH4-N in the first-stage constructed wetland demonstrated that entrainment of air during draining of constructed wetland could strengthen the removal of COD and NH4-N. Temperature had no significant effect on COD degradation while obviously affected the removal of NH4-N.

Nutrient removal mechanisms in constructed wetlands and sustainable water management

1999 ◽  
Vol 40 (2) ◽  
pp. 121-128 ◽  
Author(s):  
K. Sakadevan ◽  
H. J. Bavor
Keyword(s):  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Agricultural Runoff ◽  
First Year ◽  
Hydraulic Loading ◽  
P Concentration ◽  
N Removal ◽  
Influent Water ◽  
Second Year ◽  
Total P

Constructed wetland systems are used to treat domestic and industrial wastewater and agricultural runoff. In this field study the influence of hydraulic loading, retention time, water column depth and phosphorus (P) concentrations of influent wastewater on P and nitrogen (N) removal was examined in experimental constructed wetland systems. Five constructed wetlands with a surface area of 150 m2, were developed in the field. Results showed that P concentrations of water from outlets of all five systems decreased (from as low as 11% decrease for the system which received wastewater with average P concentration of 8.2 mg P L−1 to as high as 48.9% decrease for the system which received wastewater with average P concentration of 3.58 mg P L−1) compared to the influent water. The N concentrations in the outlet water were also decreased in all five systems (from as low as 26.3% decrease to as high as 77.5% decrease) compared to the influent water. The total P and N in the wetland sediment increased in the first year in all five systems but were unchanged at the end of the second year. The study showed that low hydraulic loading and greater retention times positively enhanced removal of P and N from wastewater in constructed wetland systems.

TRANSFORMATION FEATURES OF THE DRAINED PEAT-PODZOL GLEY SOILS UNDER LONG-TERM AGRICULTURAL USE

1970 ◽  
pp. 25-28
Author(s):  
V. А. Shevchenko ◽  
A. V. Nefedov ◽  
A. V. Ilinskiy ◽  
А. Е. Morozov
Keyword(s):  
Humus Horizon ◽  
Total Carbon ◽  
Mineral Fertilizers ◽  
Peat Layer ◽  
Organic And Mineral Fertilizers ◽  
Mineralization Processes ◽  
Agricultural Use ◽  
Phosphorus And Potassium ◽  
Plough Layer

Long-term observations of the drained soil of peat-podzolic-gley light loam on ancient alluvial sands state on the example of the meliorative object "Tinky-2" showed that under the influence of agricultural use in the soil, the organic matter mineralization processes are accelerated. During the drainage process, the soil evolutionarily suffered the following changes: the peat layer was compacted, humified and mineralized, which was a reason of the transformation them into the humus horizon. Based on the monitoring studies results it was established that during 21 intensive use years the peat layer thickness was decreased by 74.5% and amounted to 5.51 inch, which in the following 20 years was decreased to a layer of 1.18 inch, and for another 14 years it became a homogeneous humus horizon containing difficulty identifiable plant remains. For half a century, the bulk density increased by 6 times and the total moisture capacity of the soil decreased by 3.6 times. Other indicators were changed significantly. So, the ash content by 2016 increased from 11.2% to 52.7%. It was a reason of the plough-layer decreasing and it mixes with the mineral sand horizon during plowing. It should also be noted that the total nitrogen content in the soil decreased by 1.13%, and total carbon by 15.3% from 1982 to 2016. The dynamics of changes in the soil acidity, phosphorus and potassium content is associated with the introduction of calcareous, organic and mineral fertilizers in the 1980s. The unsystematic exploitation of such soils leads to decrease in the agricultural products productivity and increase in energy costs. When planning these soils usage in agricultural production, it is necessary to develop and implement modern melioration technologies and techniques aimed to increase soil fertility.

Long-term Effects of Triazol Growth Regulators on Stem Elongation of Rhododendron and Kalmia

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 436E-436
Author(s):  
Martin P.N. Gent
Keyword(s):  
Dose Response ◽  
Growth Regulator ◽  
Stem Elongation ◽  
Spray Application ◽  
Long Term Effects ◽  
Potted Plants ◽  
Response Coefficient ◽  
Wide Range ◽  
Second Year

The persistence of effects of paclobutrazol or uniconazol on stem elongation was determined for several years after large-leaf Rhododendron and Kalmia latifolia were treated with a single-spray application of these triazol growth-regulator chemicals. Potted plants were treated in the second year from propagation, and transplanted into the field in the following spring. The elongation of stems was measured in the year of application and in the following 2 to 4 years. Treatments with a wide range of doses were applied in 1991, 1992, or 1995. For all except the most-dilute applications, stem elongation was retarded in the year following application. At the highest doses, stem growth was inhibited 2 years following application. The results could be explained by a model of growth regulator action that assumed stem elongation was inversely related to amount of growth regulator applied. The dose response coefficient for paclobutrazol was less than that for uniconazol. The dose that inhibited stem elongation one-half as much as a saturating dose was about 0.5 and 0.05 mg/plant, for paclobutrazol and uniconazol, respectively. The dose response coefficient decreased exponentially with time after application, with an exponential time constant of about 2/year. The model predicted a dose of growth regulator that inhibited 0.9 of stem elongation immediately after application would continue to inhibit 0.5 of stem elongation in the following year.

Impact of Dursban and Abate on Microbial Numbers and Some Chemical Properties of Standing Ponds

1975 ◽  
Vol 10 (1) ◽  
pp. 33-41 ◽  
Author(s):  
J. Butcher ◽  
M. Boyer ◽  
CD. Fowle
Keyword(s):  
Carbon Dioxide ◽  
Active Ingredient ◽  
Algal Blooms ◽  
Chemical Properties ◽  
Total Carbon ◽  
Dissolved Carbon ◽  
Photosynthetic Productivity ◽  
Dissolved Carbon Dioxide ◽  
Microbial Numbers

Abstract Eleven small ponds, lined with polyethylene, were used to assess the consequences of applications of *DursbanR at 0.004, 0.030, 0.100 and 1.000 ppm and AbateR at 0.025 and 0.100 ppm active ingredient. The treated ponds showed a more pronounced long-term increase in pH and dissolved oxygen and decreasing total and dissolved carbon dioxide in comparison with untreated ponds. Algal blooms were of longer duration in treated ponds than in controls. Total photosynthetic productivity was higher in treated ponds but bacterial numbers did not change significantly. Photosynthetic productivity was estimated by following the changes in total carbon dioxide.

scholarly journals Nutrient retention behind a tropical mega-dam: a case study of the Sardar Sarovar Dam, India

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Harish Gupta ◽  
S. Kiran Kumar Reddy ◽  
Mounika Chiluka ◽  
Vamshikrishna Gandla
Keyword(s):  
Arabian Sea ◽  
Inorganic Nitrogen ◽  
Nutrient Retention ◽  
Significant Loss ◽  
N Removal ◽  
Narmada River ◽  
Sardar Sarovar ◽  
The Impact

AbstractIn this study, we demonstrate the impact of the construction of a mega-dam on the nutrient export regime of a large tropical river into the Arabian Sea. Long-term (11 years) fortnight nutrient parameters, upstream and downstream to Sardar Sarovar (SS) Dam, were examined to determine the periodical change in nutrient fluxes from the Narmada River, India. During this 11-year period, the average discharge of the Narmada River upstream to Rajghat (35.3 km3 year−1) was higher than that of downstream at Garudeshwar (33.9 km3 year−1). However, during the same period, the suspended sediment load was reduced by 21 million tons (MT) from 37.9 MT at Rajghat to 16.7 MT at Garudeshwar. Similarly, mean concentrations of dissolved silica (DSi) reduced from 470 (upstream) to 214 µM (downstream), dissolved inorganic phosphate (DIP) from 0.84 to 0.38 µM, and dissolved inorganic nitrogen (DIN) from 43 to 1.5 µM. It means that about 54%, 55%, and 96% flux of DSi, DIP, and DIN retained behind the dam, respectively. The estimated denitrification rate (80,000 kg N km−2 year−1) for the reservoir is significantly higher than N removal by lentic systems, globally. We hypothesize that processes such as biological uptake and denitrification under anoxic conditions could be a key reason for the significant loss of nutrients, particularly of DIN. Finally, we anticipated that a decline in DIN fluxes (by 1.13 × 109 mol year−1) from the Narmada River to the Arabian Sea might reduce the atmospheric CO2 fixation by 7.46 × 109 mol year−1.

scholarly journals Nitrogen removal processes in lakes of different trophic states from on-site measurements and historic data

2021 ◽  
Vol 83 (2) ◽  
Author(s):  
Beat Müller ◽  
Raoul Thoma ◽  
Kathrin B. L. Baumann ◽  
Cameron M. Callbeck ◽  
Carsten J. Schubert
Keyword(s):  
Eutrophic Lake ◽  
Oligotrophic Lake ◽  
Removal Rates ◽  
N Removal ◽  
Central Switzerland ◽  
Denitrification Activity ◽  
Historic Data ◽  
Anthropogenic Nitrogen ◽  
Removal Processes ◽  
Sediment Interface

AbstractFreshwater lakes are essential hotspots for the removal of excessive anthropogenic nitrogen (N) loads transported from the land to coastal oceans. The biogeochemical processes responsible for N removal, the corresponding transformation rates and overall removal efficiencies differ between lakes, however, it is unclear what the main controlling factors are. Here, we investigated the factors that moderate the rates of N removal under contrasting trophic states in two lakes located in central Switzerland. In the eutrophic Lake Baldegg and the oligotrophic Lake Sarnen, we specifically examined seasonal sediment porewater chemistry, organic matter sedimentation rates, as well as 33-year of historic water column data. We find that the eutrophic Lake Baldegg, which contributed to the removal of 20 ± 6.6 gN m−2 year−1, effectively removed two-thirds of the total areal N load. In stark contrast, the more oligotrophic Lake Sarnen contributed to 3.2 ± 4.2 gN m−2 year−1, and had removed only one-third of the areal N load. The historic dataset of the eutrophic lake revealed a close linkage between annual loads of dissolved N (DN) and removal rates (NRR = 0.63 × DN load) and a significant correlation of the concentration of bottom water nitrate and removal rates. We further show that the seasonal increase in N removal rates of the eutrophic lake correlated significantly with seasonal oxygen fluxes measured across the water–sediment interface (R2 = 0.75). We suggest that increasing oxygen enhances sediment mineralization and stimulates nitrification, indirectly enhancing denitrification activity.

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