scholarly journals Importance of the Submerged Zone during Dry Periods to Nitrogen Removal in a Bioretention System

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 876 ◽  
Author(s):  
Kangmao He ◽  
Huapeng Qin ◽  
Fan Wang ◽  
Wei Ding ◽  
Yixiang Yin
Keyword(s):  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Early Stage ◽  
Nitrogen Concentration ◽  
Rainfall Amount ◽  
Dry Period ◽  
Upward Trend ◽  
Influent Concentration ◽  
Bioretention System ◽  
Exponential Decline

Adding a submerged zone (SZ) is deemed to promote denitrification during dry periods and thus improve NO3− removal efficiency of a bioretention system. However, few studies had investigated the variation of nitrogen concentration in the SZ during dry periods and evaluated the effect of the variation on nitrogen removal of the bioretention system. Based on the experiment in a mesocosm bioretetion system with SZ, this study investigated the variation of nitrogen concentration of the system under 17 consecutive cycles of wet and dry alternation with varied rainfall amount, influent nitrogen concentration and antecedent dry periods (ADP). The results indicated that (1) during the dry periods, NH4+ concentrations in SZ showed an exponential decline trend, decreasing by 50% in 12.9 ± 7.3 h; while NO3− concentrations showed an inverse S-shape declining trend, decreasing by 50% in 18.8 ± 6.4 h; (2) during the wet periods, NO3− concentration in the effluent showed an S-shape upward trend; and at the early stage of the wet periods, the concentration was relatively low and significantly correlated with ADP, while the corresponding volume of the effluent was significantly correlated with the SZ depth; (3) in the whole experiment, the contribution of nitrogen decrease in SZ during dry periods to NH4+ and NO3− removal accounted for 12% and 92%, respectively; and the decrease of NO3− in SZ during the dry period was correlated with the influent concentration in the wet period and the length of the dry period.

scholarly journals Importance of the Submerged Zone during Dry Periods to Nitrogen Removal in a Bioretention System

2020 ◽  
Author(s):  
Kangmao He ◽  
Huapeng Qin ◽  
Fan Wang ◽  
Wei Ding ◽  
Yixiang Yin
Keyword(s):  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Early Stage ◽  
Nitrogen Concentration ◽  
Rainfall Amount ◽  
Dry Period ◽  
Upward Trend ◽  
Bioretention System ◽  
N Removal ◽  
Exponential Decline

Adding a submerged zone (SZ) is deemed to promote denitrification during dry periods and thus improve NO3--N removal efficiency of a bioretention system. However, few studies had investigated the variation of nitrogen concentration in the SZ during dry periods and evaluated the effect of the variation on nitrogen removal of the bioretention system. Based on the experiment in a mesocosm bioretetion system with SZ, this study investigated the variation of nitrogen concentration of the system under 17 consecutive cycles of wet and dry alternation with varied rainfall amount, influent nitrogen concentration and antecedent dry periods (ADP). The results indicated that (1) during the dry periods, NH4+-N concentrations in SZ showed an exponential decline trend, decreasing by 50% in 12.9 ± 7.3 hours; while NO3--N concentrations showed an inverse S-shape decline trend, decreasing by 50% in 18.8 ± 6.4 hours; (2) during the wet periods, NO3--N concentration in the effluent showed an S-shape upward trend; and at the early stage of the wet periods, the concentration was relatively low and significantly correlated with ADP, while the corresponding volume of the effluent was significantly correlated with the SZ depth; (3) in the whole experiment, the contribution of nitrogen decrease in SZ during dry periods to NH4+-N and NO3--N removal accounted for 12% and 92%, respectively; and the decrease of NO3--N in SZ during the dry period was correlated with the influent concentration in the wet period and the length of the dry period.

scholarly journals The Common Approaches of Nitrogen Removal in Bioretention System

2021 ◽  
Vol 13 (5) ◽  
pp. 2575
Author(s):  
Wafaa Ali ◽  
Husna Takaijudin ◽  
Khamaruzaman Wan Yusof ◽  
Manal Osman ◽  
Abdurrasheed Sa’id Abdurrasheed
Keyword(s):  
Nitrogen Removal ◽  
Best Management Practices ◽  
Management Practices ◽  
Nitrogen Concentration ◽  
Soil Conditions ◽  
Stormwater Quality ◽  
Filter Media ◽  
The Third ◽  
Bioretention System ◽  
N Removal

Bioretention is considered one of the best management practices (BMPS) for managing stormwater quality and quantity. The bioretention system has proven good performance in removing total suspended solids, oil, and heavy metals. The nitrogen (N) removal efficiency of the bioretention system is insufficient, however, due to the complex forms of nitrogen. Therefore, this paper aims to review recent enhancement approaches to nitrogen (N) removal and to discuss the factors influencing bioretention efficiency. To improve bioretention efficiency, several factors should be considered when designing bioretention systems, including nitrogen concentration, climate factors, and hydrological factors. Further, soil and plant selection should be appropriate for environmental conditions. Three design improvement approaches have been reviewed. The first is the inclusion of a saturated zone (SZ), which has been used widely. The SZ is shown to have the best performance in nitrogen removal. The second approach (which is less popular) is the usage of additives in the form of a mixture with soil media or as a separated layer. This concept is intended to be applied in tropical regions with wet soil conditions and a short dry period. The third approach combines the previous two approaches (enhanced filter media and applying a SZ). This approach is more efficient and has recently attracted more attention. This study suggests that further studies on the third approach should be carried out. Applying amendment material through filter media and integrating it with SZ provides appropriate conditions to complete the nitrogen cycle. This approach is considered a promising method to enhance nitrogen removal. In general, the bioretention system offers a promising tool for improving stormwater quality.

Nitrogen removal in a submerged filter with no effluent recirculation

2000 ◽  
Vol 42 (3-4) ◽  
pp. 51-58 ◽  
Author(s):  
P.C. Chui ◽  
Y. Terashima ◽  
J.H. Tay ◽  
H. Ozaki ◽  
S. Jeyaseelan
Keyword(s):  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Loading Rate ◽  
Industrial Effluents ◽  
Anaerobic Treatment ◽  
Anoxic Zone ◽  
Influent Concentration ◽  
Test Conditions ◽  
Effluent Recirculation ◽  
Effluent Recycling

The performance of a partly aerated submerged filter in treating high nitrogenous wastewaters such as industrial effluents after anaerobic treatment was investigated in this study. The filter was operated without effluent recycling and its response to various test conditions of aeration rates, hydraulic loads, COD/N ratios and hydraulic retention times was evaluated. Results indicated that for an influent concentration of 250 mg N/L and for a loading rate of 0.7 kg N/m3.d, 60% of the nitrogen can be removed. For a reduced loading rate of 0.25 kg N/m3.d, nitrogen removal efficiency could reach 86%. Denitrification was hypothesized to have taken place inside the support media in the aerated zone of the filter where oxygen was lacking as well as at locations immediately below the air diffuser where an anoxic zone was formed with the back-flowing nitrified substrate.

Removal of Ammonia Nitrogen from Landfill Leachate by Ultrasound/Ultraviolet Process

2013 ◽  
Vol 448-453 ◽  
pp. 536-539
Author(s):  
Bin Liu ◽  
Xu Ya Peng ◽  
Qi Tian ◽  
Hua Zhao
Keyword(s):  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Landfill Leachate ◽  
Nitrogen Concentration ◽  
Ammonia Nitrogen ◽  
Aeration Rate ◽  
Ammonia Removal ◽  
Ultrasonic Power ◽  
High Concentration ◽  
Leachate Treatment

Landfill leachate treatment is a major problem to be solved in the field of environmental protection, and ammonia nitrogen is one of the major pollutants in landfill leachate, whose processing technology needs further improvement. In this paper, ultrasound/ultraviolet co-oxidation technology was directly applied to the treatment of high concentration landfill leachate without the pretreatment operations of dilution, filter, and adjusting the pH conditions. The results showed that: ultrasonic and ultraviolet had certain effects on the ammonia nitrogen removal, and the ammonia nitrogen removing effects became better when the ultrasonic power was greater, or the ultraviolet wavelength was shorter. When the ultrasonic power was 100 W, the ammonia nitrogen removal efficiency was 25.2%, and the UV of 254 nm could decompose 20.2% of the ammonia nitrogen in landfill leathate. In the condition of aeration, ultrasonic and ultraviolet had good synergistic effect on leachate ammonia nitrogen treatment. When the ultrasonic power was 100 W, UV wavelength was 254 nm, and the aeration rate was 150 L/h, the ammonia removal efficiency of high concentration leachate (ammonia nitrogen concentration of 1800 mg/L) reached 98.5% after 6 hours. The paper's research results provide a useful reference for the removal of landfill leachate ammonia nitrogen.

scholarly journals Heterotrophic nitrogen removal by a newly-isolated microorganism, Oligella sp. XS68

2020 ◽  
Vol 85 (3) ◽  
pp. 395-405
Author(s):  
Hong Yan ◽  
Jian Wu ◽  
Pei Xu
Keyword(s):  
Carbon Source ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Sodium Succinate ◽  
Nitrogen Concentration ◽  
Ammonium Nitrogen ◽  
Single Factor ◽  
Promising Candidate

A new bacterium capable of heterotrophic nitrogen removal was isolated and identified as Oligella sp. XS68. The strain exhibited efficient heterotrophic nitrogen removal capabilities, with a low accumulation of nitrification products. Single-factor experiments indicated that efficient nitrogen removal and growth of the strain XS68 occurred with sodium succinate as the carbon source, C/N ratio 15, pH 6.0?9.0, temperature 30?37 ?C, and shaking speed 160?200 rpm. The removal efficiency of ammonium nitrogen could achieve 98 % within 96 h when the initial nitrogen concentration was 421.3 mg L-1. These findings demonstrate that XS68 is a promising candidate for nitrogen removal in wastewater treatments.

Performance of Treatment of Domestic Wastewater by Sequencing Batch Biofilm Reactor

2014 ◽  
Vol 955-959 ◽  
pp. 2318-2321
Author(s):  
Dong Yuan
Keyword(s):  
Removal Efficiency ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Nitrogen Concentration ◽  
Domestic Wastewater ◽  
Ammonium Nitrogen ◽  
Biofilm Reactor ◽  
Simultaneous Nitrification And Denitrification ◽  
Sequencing Batch Biofilm Reactor ◽  
Total Nitrogen Removal

The objective of this work was to evaluate the performances of A lab-scale innovative sequencing batch biofilm reactor (SBBR) to treat domestic wastewater,in which a acryl cylinder (height 200 mm, diameter 70 mm) was equipped and many fiber threads were attached to the surface of the cylinder as the bacteria carrier. No time and volume for settling was required in this system. After one year’s operation, each parameter achieved the wastewater discharged criterion in 2 cycles (4 h). It was found that COD removal efficiency was up to 90% in 3 h, and ammonium nitrogen concentration approached the least value; total nitrogen removal efficiency reached 55%-71%. In this SBBR system simultaneous nitrification and denitrification was completed at the end of 2 cycles.

Performance of a partly aerated biofilter in the removal of nitrogen

1996 ◽  
Vol 34 (1-2) ◽  
pp. 187-194 ◽  
Author(s):  
P. C. Chui ◽  
Y. Terashima ◽  
J. H. Tay ◽  
H. Ozaki
Keyword(s):  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Loading Rate ◽  
Nitrogen Concentration ◽  
Fixed Bed ◽  
Bulk Liquid ◽  
Carbon Oxidation ◽  
High Nitrogen ◽  
Volumetric Loading ◽  
High Nitrogen Concentration

The removal efficiency of nitrogen and organic matter in an anoxic/aerobic upflow fixed bed filter was studied. Tests were carried out on the effects of aeration, hydraulic loading rate, and COD/N ratio on nitrogen removal and carbon oxidation. A synthetic high nitrogen concentration wastewater was used as substrate feed in the study. At an influent concentration of 250 mg N/L, and for volumetric loadings of up to 1 kg N/m3.day, between 41% and 86% of the nitrogen was removed. This was achieved without the recycling of effluent for denitrification. Nitrogen removal was possible when simultaneous denitrification took place inside the support media where oxygen was lacking. COD removal efficiency was consistently above 95% even at a high volumetric loading of 5 kg COD/m3.day and a bulk liquid dissolved oxygen level as low as 1.1 mg/L.

scholarly journals The effect of metabolism on the course of labor and the postpartum period in highly productive cows

2020 ◽  
Vol 17 ◽  
pp. 00256
Author(s):  
Murat Baimishev ◽  
Sergey Eremin ◽  
Kirill Plemyashov ◽  
Hamidulla Baimishev ◽  
Igor Konopeltsev ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Postpartum Period ◽  
Early Stage ◽  
Antioxidant Properties ◽  
Antioxidant Systems ◽  
Dry Period ◽  
Blood Samples ◽  
Start Up ◽  
Significant Difference ◽  
Duration Of Pregnancy

The purpose of the research is to determine the etiopathogenesis of reproductive dysfunction in highly productive cows. For this, one group of cows was formed on the principle of paranalogs in the amount of 37 animals inseminated in the first sexual hunt after calving, followed by taking blood samples from them using the Monovet system, considering the duration of pregnancy. During the start-up period, blood was taken 1–4 days before calving and on the first day after calving. A total of 253 blood samples were examined. Subsequently, depending on the effectiveness of insemination, animals were divided into two groups. The first group included inseminated cows after the first insemination (20 animals), the second group included 17 unfertilized cows after the first insemination. Subsequently, blood was taken from animals considering the course of childbirth and the postpartum period. Blood counts were studied according to generally accepted methods using certified equipment. The study found that at an early stage of pregnancy, cows have a significant difference in lipid metabolism and in their peroxidation, in the state of antioxidant systems compared to unstable animals. In the process of pregnancy development in cows, there is a decrease in the level of total lipids and their class, and the accumulation of products of transoxidation of lipids is reduced. In animals with retention of the placenta, a low lipid metabolism and a higher level of peroxidation were established already in the dry period. After calving, this difference increases. The obtained data can be used to develop an algorithm for the prevention of postpartum complications in cows by using substances with antioxidant properties.

scholarly journals Start-up Strategies for Anaerobic Ammonia Oxidation (Anammox) in In-Situ Nitrogen Removal from Polluted Groundwater in Rare Earth Mining Areas

2021 ◽  
Vol 13 (8) ◽  
pp. 4591
Author(s):  
Shuanglei Huang ◽  
Daishe Wu
Keyword(s):  
Rare Earth ◽  
Low Temperature ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Ex Situ ◽  
High Concentration ◽  
Low Concentration ◽  
Start Up ◽  
Anammox Activity

The tremendous input of ammonium and rare earth element (REE) ions released by the enormous consumption of (NH4)2SO4 in in situ leaching for ion-adsorption RE mining caused serious ground and surface water contamination. Anaerobic ammonium oxidation (anammox) was a sustainable in situ technology that can reduce this nitrogen pollution. In this research, in situ, semi in situ, and ex situ method of inoculation that included low-concentration (0.02 mg·L−1) and high-concentration (0.10 mg·L−1) lanthanum (La)(III) were adopted to explore effective start-up strategies for starting up anammox reactors seeded with activated sludge and anammox sludge. The reactors were refrigerated for 30 days at 4 °C to investigate the effects of La(III) during a period of low-temperature. The results showed that the in situ and semi in situ enrichment strategies with the addition of La(III) at a low-concentration La(III) addition (0.02 mg·L−1) reduced the length of time required to reactivate the sludge until it reached a state of stable anammox activity and high nitrogen removal efficiency by 60–71 days. The addition of La(III) promoted the formation of sludge floc with a compact structure that enabled it to resist the adverse effects of low temperature and so to maintain a high abundance of AnAOB and microbacterial community diversity of sludge during refrigeration period. The addition of La(III) at a high concentration caused the cellular percentage of AnAOB to decrease from 54.60 ± 6.19% to 17.35 ± 6.69% during the enrichment and reduced nitrogen removal efficiency to an unrecoverable level to post-refrigeration.

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