scholarly journals The effect of natural materials using as sediment remediation on phosphorus and nitrogen control in a mesocosm

2020 ◽  
Author(s):  
Mengjuan Tang ◽  
Qinghui Deng ◽  
Xiaowen Li ◽  
Xiuyun Cao ◽  
Zhimin Zhang ◽  
...  
Keyword(s):  
Water Column ◽  
Clay Mineral ◽  
Sugarcane Bagasse ◽  
Natural Material ◽  
Sediment Remediation ◽  
Adsorption Ability ◽  
N Accumulation ◽  
P Adsorption ◽  
P Release ◽  
N Removal

Abstract Background Nitrogen (N) and phosphorus (P) control in sediment remediation through adding natural material has been paid more and more attention. In this study, different natural material including iron-rich clay mineral, calcite, kaoline, sugarcane bagasse and Phragmites detritus was applied to test the effect on N and P control in a mesocosm experiment. Results Iron-rich clay mineral and Phragmites detritus had an obvious advantage on P control in terms of almost undetectable soluble reactive phosphorus (SRP) in water column throughout the experiment, which could be explained by strong P adsorption ability. The high available organic carbon in sediment and water column after sugarcane bagasse addition provided enough electron donors for denitrification and dissimilatory nitrate reduction to ammonium (DNRA), which was responsible for nitrate (NO 3 - -N) deficiency and ammonium (NH 4 + -N) accumulation in water column. Also this resulted in anaerobic status, further fuelling P release from iron-bound P induced by anoxia. Thus, sugarcane bagasse application should be considered its dosage in order to balance the denitrification and DNRA as well as P release. Calcite and Phragmites detritus should be recommended as remediation material for N removal according to the significant promotion of denitrification and limitation of DNRA, finally resulting in low NO 3 - -N and NH 4 + -N. These results could be explained by the shift of functional microbial community composition and abundance after natural material addition. Conclusions Iron-rich clay mineral and Phragmites detritus should be regarded as the promising sediment remediation material for P immobilization due to the increase of P adsorption ability. Taken together, the selection of sediment remediation material should combine the N and P coupling relationship, avoiding that NO 3 - -N removal caused the P leaching or NH 4 + -N accumulation.

scholarly journals The effects of red soil in removing phosphorus from water column and reducing phosphorus release from sediment in Lake Taihu

2014 ◽  
Vol 69 (5) ◽  
pp. 1052-1058 ◽  
Author(s):  
Lichun Dai ◽  
Gang Pan
Keyword(s):  
Water Column ◽  
Lake Taihu ◽  
Cost Effective ◽  
Phosphorus Release ◽  
Red Soil ◽  
Natural Soil ◽  
P Adsorption ◽  
P Release ◽  
The Cost ◽  
Short Time

A natural red soil and a lanthanum-modified soil (LMS) were tested to compare their phosphorus (P) adsorption capacities and their effectiveness in removing P from the water column and reducing P release from sediment. The equilibrium of P adsorption demonstrated that the maximum P adsorption for the soil was 1.29 and 2.22 mg g−1 at pH 8.5 and 5.5, respectively, and for the LMS these were increased by 45.6 and 77.6% at pH 8.5 and 5.5, respectively, indicating that the soil was effective in P adsorption and the doping of lanthanum could substantially increase P adsorption. The sediment–water column incubation showed that, due to the P adsorption of the soil and LMS, the total P in the water column decreased by 58.5, 60.6, 68.2 and 77.2% for 180 g m−2 soil, 900 g m−2 soil, 180 g m−2 LMS and 900 g m−2 LMS treated systems, respectively, in a short time (6 h), and the capping layer substantially reduced the P release from sediment during column incubation, indicating that the soils were effective in reducing internal P load. However, considering the cost of LMS, the natural soil was suggested to be a cost-effective material to control internal P load.

scholarly journals An Exploration of Seaweed Polysaccharides Stimulating Denitrifying Bacteria for Safer Nitrate Removal

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3390
Author(s):  
Hui Zhang ◽  
Lin Song ◽  
Xiaolin Chen ◽  
Pengcheng Li
Keyword(s):  
Growth Rate ◽  
Bacillus Subtilis ◽  
Nitrate Removal ◽  
Denitrifying Bacteria ◽  
Soil Salinization ◽  
Nitrate Content ◽  
Weak Efficiency ◽  
N Accumulation ◽  
N Removal ◽  
Intensively Managed

Excessive use of nitrogen fertilizer in intensively managed agriculture has resulted in abundant accumulation of nitrate in soil, which limits agriculture sustainability. How to reduce nitrate content is the key to alleviate secondary soil salinization. However, the microorganisms used in soil remediation cause some problems such as weak efficiency and short survival time. In this study, seaweed polysaccharides were used as stimulant to promote the rapid growth and safer nitrate removal of denitrifying bacteria. Firstly, the growth rate and NO3−-N removal capacity of three kinds of denitrifying bacteria, Bacillus subtilis (BS), Pseudomonas stutzeri (PS) and Pseudomonas putida (PP), were compared. The results showed that Bacillus subtilis (BS) had a faster growth rate and stronger nitrate removal ability. We then studied the effects of Enteromorpha linza polysaccharides (EP), carrageenan (CA), and sodium alginate (AL) on growth and denitrification performance of Bacillus subtilis (BS). The results showed that seaweed polysaccharides obviously promoted the growth of Bacillus subtilis (BS), and accelerated the reduction of NO3−-N. More importantly, the increased NH4+-N content could avoid excessive loss of nitrogen, and less NO2−-N accumulation could avoid toxic effects on plants. This new strategy of using denitrifying bacteria for safely remediating secondary soil salinization has a great significance.

Bamboo as Solid Carbon Source for De-Nitrification

2013 ◽  
Vol 807-809 ◽  
pp. 1330-1335
Author(s):  
Yin Mei Wang
Keyword(s):  
Carbon Source ◽  
Solid Phase ◽  
Influencing Factor ◽  
Flow Mode ◽  
Nitrite Accumulation ◽  
N Accumulation ◽  
Nitrate N ◽  
N Removal ◽  
Single Carbon Source ◽  
As Solid Phase

This study was conducted to investigate the efficiency and characteristics of de-nitrification using bamboo as solid phase carbon source in a batch and continuous flow mode. Compared to no solid phase carbon source system, the higher nitrate-N removal efficiency and the less nitrite-N accumulation was observed in a de-nitrification system by using bamboo as solid phase carbon source. The results showed that nitrate-N volumetric load averaged between 2.09 mg/L.h when filamentous bamboo as single carbon source, and mean nitrite-N accumulations was only 0.23 mg as 1 g nitrate-N was removed. Moreover, temperature was an important influencing factor for nitrate-N volumetric load and nitrite accumulation. In addition, refractory organic compounds and nitrate-N can simultaneous remove.

scholarly journals Removal of ammonia-nitrogen in wastewater using a novel poly ligand exchanger-Zn(II)-loaded chelating resin

2019 ◽  
Vol 79 (1) ◽  
pp. 126-136 ◽  
Author(s):  
Yan Chen ◽  
Wei Chen ◽  
Quanzhou Chen ◽  
Changhong Peng ◽  
Dewen He ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Ammonia Nitrogen ◽  
Chelating Resin ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Adsorption Ability ◽  
N Removal ◽  
Loaded Resin ◽  
Effects Of Ph ◽  
Pseudo Second Order

Abstract In this study, a novel poly ligand exchanger-Zn(II)-loaded resin was designed to effectively remove ammonia-nitrogen (NH3-N) from wastewater. The surface morphology and structure of the Zn-loaded resin were characterized using scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and Fourier transform infrared spectroscopy (FTIR), respectively. SEM shows the surfaces of the Zn(II)-loaded resin were rough and nonporous and EDS demonstrated that Zn2+ was loaded onto the resin successfully. In addition, the combination form of Zn(II) with NH3-N adsorption reagent was revealed by FTIR spectra; the complex could be R-N-R-O-Zn-O-R-N-R and R-N-R-(O-Zn)2. The kinetics and equilibrium of the NH3-N adsorption onto the Zn(II)-loaded resin has been investigated. The effects of pH, reaction time, and temperature on NH3-N removal from wastewater by Zn(II)-loaded resin were investigated, and the results showed that the maximum adsorption capacity reached 38.55 mg/g at pH 9.54 at 298 K in 240 min. The adsorption ability of the modified resin decreased with an increase in temperature. Moreover, the NH3-N adsorption followed a pseudo-second-order kinetic process. The kinetic data demonstrated that the adsorption process might be limited by a variety of mechanisms. The study can provide the scientific foundation for the extensive application of a novel poly ligand exchanger-Zn(II)-loaded resin to remove NH3-N from wastewater.

Stormwater nitrogen removal performance of a floating treatment wetland

2013 ◽  
Vol 68 (7) ◽  
pp. 1657-1664 ◽  
Author(s):  
Karine E. Borne ◽  
Chris C. Tanner ◽  
Elizabeth A. Fassman-Beck
Keyword(s):  
Treatment Wetland ◽  
N Accumulation ◽  
Effluent Quality ◽  
Retention Ponds ◽  
Floating Treatment Wetland ◽  
N Removal ◽  
Higher Temperature ◽  
And Control ◽  
Stormwater Retention

The nitrogen (N) removal efficiency and effluent quality of two parallel stormwater retention ponds, one retrofitted with a floating treatment wetland (FTW) and one without any vegetation, was compared in a field trial. This study shows that inclusion of FTWs in stormwater retention ponds has potential to moderately improve N removal. Median FTW outlet event mean concentrations (EMCs) were lower than median inlet and control pond outlet EMCs for all species of N, except for NH4-N. Performance was statistically better from late spring to end autumn due to higher organic nitrogen (ON) removal and denitrification in presence of the FTW. Low dissolved oxygen (DO), higher temperature and increased organic matter (OM) and microbial activity below the FTW, likely facilitated the higher denitrification rates observed over this period. Greater sediment N accumulation in the FTW pond also contributed to its higher overall N removal. Higher OM availability in the FTW pond due to release of root exudates and supply of detritus from plant die-back may have contributed to floc formation in the water column, increasing particulate ON settlement. Enhanced ON mineralisation may also be responsible but was probably limited in summer due to the low DO induced by the FTW. Direct uptake by the plants appears to be of less importance.

scholarly journals The Nitrogen-Removal Efficiency of a Novel High-Efficiency Salt-Tolerant Aerobic Denitrifier, Halomonas Alkaliphile HRL-9, Isolated from a Seawater Biofilter

2019 ◽  
Vol 16 (22) ◽  
pp. 4451 ◽  
Author(s):  
Jilong Ren ◽  
Chenzheng Wei ◽  
Hongjing Ma ◽  
Mingyun Dai ◽  
Jize Fan ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Nitrogen Balance ◽  
High Efficiency ◽  
Aerobic Denitrification ◽  
Salt Tolerant ◽  
N Accumulation ◽  
Recirculating Aquaculture ◽  
N Removal ◽  
Recirculating Aquaculture Systems

Aerobic denitrification microbes have great potential to solve the problem of NO3−-N accumulation in industrialized recirculating aquaculture systems (RASs). A novel salt-tolerant aerobic denitrifier was isolated from a marine recirculating aquaculture system (RAS) and identified as Halomonas alkaliphile HRL-9. Its aerobic denitrification performance in different dissolved oxygen concentrations, temperatures, and C/N ratios was studied. Investigations into nitrogen balance and nitrate reductase genes (napA and narG) were also carried out. The results showed that the optimal conditions for nitrate removal were temperature of 30 °C, a shaking speed of 150 rpm, and a C/N ratio of 10. For nitrate nitrogen (NO3−-N) (initial concentration 101.8 mg·L−1), the sole nitrogen source of the growth of HRL-9, the maximum NO3−-N removal efficiency reached 98.0% after 24 h and the maximum total nitrogen removal efficiency was 77.3% after 48 h. Nitrogen balance analysis showed that 21.7% of NO3−-N was converted into intracellular nitrogen, 3.3% of NO3−-N was converted into other nitrification products (i.e., nitrous nitrogen, ammonium nitrogen, and organic nitrogen), and 74.5% of NO3−-N might be converted to gaseous products. The identification of functional genes confirmed the existence of the napA gene in strain HRL-9, but no narG gene was found. These results confirm that the aerobic denitrification strain, Halomonas alkaliphile HRL-9, which has excellent aerobic denitrification abilities, can also help us understand the microbiological mechanism and transformation pathway of aerobic denitrification in RASs.

A Method for Estimating Uptake and Production Rates for Urea in Seawater using [14C] Urea and [15N] Urea

1989 ◽  
Vol 46 (2) ◽  
pp. 198-202 ◽  
Author(s):  
Dennis A. Hansell ◽  
John J. Goering
Keyword(s):  
Bering Sea ◽  
Natural Populations ◽  
Particulate Fraction ◽  
Particulate Phase ◽  
N Accumulation ◽  
N Removal ◽  
Uptake Rates ◽  
Urea Production ◽  
15N Urea ◽  
Urea Method

Improved estimates of the rates of urea production and uptake by natural populations of phytoplankton were made after determining the change in 15N-atom% enrichment of urea during incubations. A [14C] urea method is described by which the change in enrichment is measured. Estimates of uptake rates are increased (relative to uptake rates determined without correction for isotope dilution) by up to 83% using a 15N accumulation model and by >210% using a 15N disappearance model. A discrepancy exists between [15N] urea removed from the aqueous phase and 15N accumulated in the particulate phase at stations occupied in the northeastern Bering Sea. The ability to find in the particulate fraction the 15N removed from solution as [15N] urea was improved by 72% following removal of the >20-μm particulate fraction. This corresponded to only a 4% reduction in the concentration of chlorophyll a and a 37% reduction in the concentration of particulate N. Removal of microzooplankton may have improved the efficiency of urea-N retention by phytoplankton.

scholarly journals Phosphorus Dynamics Associated With Organic Carbon Mineralization by Reduction of Sulfate and Iron in Sediment Exposed to Fish Farming

2021 ◽  
Vol 8 ◽  
Author(s):  
Jin-Sook Mok ◽  
Ayeon Choi ◽  
Bomina Kim ◽  
Sung-Uk An ◽  
Won-Chan Lee ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Water Column ◽  
Fish Farming ◽  
Fish Feed ◽  
Internal Source ◽  
Control Sediment ◽  
P Release ◽  
P Flux ◽  
The Impact ◽  
Total P

The expansion of the aquaculture industry has resulted in accumulation of phosphorus (P)-rich organic matter via uneaten fish feed. To elucidate the impact of fish farming on P dynamics, P speciation, and benthic P release along with partitioning of organic carbon (Corg) mineralization coupled to sulfate reduction (SR) and iron reduction (FeR) were investigated in the sediments from Jinju Bay, off the southern coast of South Korea, in July 2013. SR in the farm sediment was 6.9-fold higher than the control sediment, and depth-integrated (0–10 cm) concentrations of NH4+, PO43–, and H2S in pore water of the farm sediment were 2.2-, 3.3-, and 7.4-fold higher than that in control sediment, respectively. High biogenic-P that comprised 28% of total P directly reflected the impact of P-rich fish feed, which ultimately enhanced the bioavailability (58% of total P) of P in the surface sediment of the farm site. In the farm sediment where SR dominated Corg mineralization, H2S oxidation coupled to the reduction of FeOOH stimulated release of P bound to iron oxide, which resulted in high regeneration efficiency (85%) of P in farm sediments. Enhanced P desorption from FeOOH was responsible for the increase in authigenic-P and benthic P flux. Authigenic-P comprised 33% of total P, and benthic P flux to the overlying water column accounted for approximately 800% of the P required for primary production. Consequently, excessive benthic P release resulting directly from oversupply of P-rich fish feed was a significant internal source of P for the water column, and may induce undesirable eutrophication and harmful algal blooms in shallow coastal ecosystems.

scholarly journals Nitrite Accumulation at Low Copper Concentration in a Submerged Partial Bionitrification Reactor

2021 ◽  
Vol 43 (6) ◽  
pp. 419-427
Author(s):  
Sukru Aslan ◽  
Burhanettin Gurbuz
Keyword(s):  
Loading Rate ◽  
Accumulation Rate ◽  
Removal Rate ◽  
Synthetic Wastewater ◽  
Flow Mode ◽  
Nitrite Accumulation ◽  
N Accumulation ◽  
Operational Conditions ◽  
Support Materials ◽  
N Removal

Objectives : Effects of various Cu2+ concentrations in the synthetic wastewater on nitrite accumulation was investigated in a submerged partial biofilter reactor (SPBNR).Methods : Experiments were carried out at the constant operational conditions (T=35℃; pH=9.0 and DO=2.0 mg O2/L) by varying the concentrations between 5-50 mg Cu2+/L. The SPBNR, which was operated in an upward flow mode, set-up consisted of a cylindrical stainless steel. The support materials filling ratio was about 23% of the total reactor volume. The SPBNR was inoculated with microorganism drawn from a batch experimental biological reactor operated about one month by using the synthetic wastewater composition.Results and Discussion : Before exposure to Cu2+, the highest loading rate of 1.3 g NH4-N/(m2.day) was determined under the operational conditions. Addition of 5 µg Cu2+/L into the waters promoted the activity of organisms and the loading rate achieved to 1.6 g NH4-N/(m2.day). At the control operational condition, the ratio of NO2-N/NOx-N was determined as 0.74, while the ratio increased to 0.78 at the Cu2+ concentration of 5 µg/L.Conclusions : Results indicated that the ammonium oxidizing bacteria (AOB) is more stimulated than the nitrite oxidizing bacteria (NOB) at the concentration of 5 µg Cu2+/L. However, approximately equal NH4-N removal rate (ANRR) and NO2-N accumulation rate (NiAR) losses indicated that the AOB and NOB are approximately equally effected at the inlet concentrations of 35 and 50 µg Cu2+/L.

Performance and microbial community of a novel PVA/iron-carbon (Fe–C) immobilized bioreactor for nitrate removal from groundwater

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Qiong Wen ◽  
Junfeng Su ◽  
Guoqing Li ◽  
Tinglin Huang ◽  
Lei Xue ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
High Throughput Sequencing ◽  
Nitrate Removal ◽  
Sequencing Analysis ◽  
N Accumulation ◽  
N Removal ◽  
Carbon Nitrogen Ratio ◽  
Nitrogen Ratio ◽  
Denitrification Bioreactor ◽  
Main Component

Abstract An efficient immobilized denitrification bioreactor functioning under anaerobic conditions was developed by combining bacterial immobilization technology with iron-carbon (Fe–C) particles. The effects of key factors on nitrate (NO3 −–N) removal efficiency were invested, such as the carbon-nitrogen ratio (C/N), pH and hydraulic retention time (HRT). Experimental results show that 100.00% NO3 −–N removal efficiency and a low level of nitrite (NO2 −–N) accumulation less than 0.05 mg L−1 were obtained under the condition of a C/N ratio of 3, pH 7.0 and HRT of 6 h. Meteorological chromatographic analysis showed that the final product of denitrification was mainly nitrogen (N2). The main component of precipitation formed in the bioreactor was characterized as Fe3O4 by X-ray diffraction. High-throughput sequencing analysis indicated that the dominant bacterial class in the Fe–C bioreactor was Gammaproteobacteria, while the dominant genera were Zoogloea and Azospira, the relative abundances of which were as high as 23.25 and 15.43%, respectively.

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