scholarly journals Assessment of Nitrate Removal Capacity of Two Selected Eukaryotic Green Microalgae

Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2490
Author(s):  
Vaishali Rani ◽  
Gergely Maróti
Keyword(s):  
Nitrate Concentration ◽  
Nitrate Removal ◽  
Synthetic Wastewater ◽  
Green Microalgae ◽  
Chlorella Sp ◽  
Removal Capacity ◽  
High Nitrate Concentration ◽  
Chlamydomonas Sp ◽  
Carbohydrate Contents ◽  
Phosphate Medium

Eutrophication is a leading problem in water bodies all around the world in which nitrate is one of the major contributors. The present study was conducted to study the effects of various concentrations of nitrate on two eukaryotic green microalgae, Chlamydomonas sp. MACC-216 and Chlorella sp. MACC-360. For this purpose, both microalgae were grown in a modified tris-acetate-phosphate medium (TAP-M) with three different concentrations of sodium nitrate, i.e., 5 mM (TAP-M5), 10 mM (TAP-M10) and 15 mM (TAP-M15), for 6 days and it was observed that both microalgae were able to remove nitrate completely from the TAP-M5 medium. Total amount of pigments decreased with the increasing concentration of nitrate, whereas protein and carbohydrate contents remained unaffected. High nitrate concentration (15 mM) led to an increase in lipids in Chlamydomonas sp. MACC-216, but not in Chlorella sp. MACC-360. Furthermore, Chlamydomonas sp. MACC-216 and Chlorella sp. MACC-360 were cultivated for 6 days in synthetic wastewater (SWW) with varying concentrations of nitrate where both microalgae grew well and showed an adequate nitrate removal capacity.

scholarly journals Ammonium and phosphate removal using batch laboratory cultures by microalgae and cyanobacteria isolated from Costa Rica water bodies

2018 ◽  
Vol 66 (1-1) ◽  
pp. 83
Author(s):  
Manuel Campos-Rudin ◽  
Ana Margarita Silva-Benavides
Keyword(s):  
Costa Rica ◽  
Phosphate Concentration ◽  
Phosphate Removal ◽  
Green Microalgae ◽  
Wastewater Reclamation ◽  
Ammonium Removal ◽  
Chlorella Sp ◽  
High Concentrations ◽  
Chlamydomonas Sp ◽  
Synechocystis Sp

This research analyzed three green microalgae (Scenedesmus sp., Chlamydomonas sp., and Chlorella sp.) and two cyanobacteria (Synechocystis sp. as unicellular strain and Nostoc sp. as filamentous strain) native from Costa Rica to remove high concentrations of ammonium and phosphate. Cultures were exposed for 120 h to initial concentrations of 70 mgL-1 ammonium and 9 mgL-1 phosphate, under constant light intensity of 60 µmol m-2s-1. Chlorella sp. showed the highest growth rate, followed by Chlamydomonas sp. and the cyanobacteria Nostoc sp. In contrast, Scenedesmus sp. and Synechocystis sp. cultures grew less than the other ones. The highest percentage of ammonium removal was achieved with Chlorella sp. followed by Chlamydomonas sp. and Synechocystis sp., then Scenedesmus sp. and Nostoc sp. Microalgae removed totally the initial phosphate concentration within 72 h, while cyanobacteria Synechocystis sp. and Nostoc sp. removed phosphate partially. These microorganisms are promising for wastewater reclamation.

Denitrification under high nitrate concentration and alternating anoxic conditions

1999 ◽  
Vol 33 (15) ◽  
pp. 3311-3320 ◽  
Author(s):  
D Bilanovic ◽  
P Battistoni ◽  
F Cecchi ◽  
P Pavan ◽  
J Mata-Alvarez
Keyword(s):  
Nitrate Concentration ◽  
Anoxic Conditions ◽  
High Nitrate Concentration

Comparison of denitrification performances using PLA/starch with different mass ratios as carbon source

2015 ◽  
Vol 71 (7) ◽  
pp. 1019-1025 ◽  
Author(s):  
Chuanfu Wu ◽  
Danqi Tang ◽  
Qunhui Wang ◽  
Juan Wang ◽  
Jianguo Liu ◽  
...  
Keyword(s):  
Carbon Source ◽  
Groundwater Remediation ◽  
Nitrate Concentration ◽  
Starch Content ◽  
Nitrate Removal ◽  
Carbon Sources ◽  
National Standard ◽  
Biofilm Carrier ◽  
Carbon Release ◽  
Biological Nitrate Removal

A suitable carbon source is significant for biological nitrate removal from groundwater. In this study, slow-release carbon sources containing polylactic acid (PLA) and starch at 8:2, 7:3, 6:4, 5:5, 4:6, and 3:7 ratios were prepared using a blending and fusing technique. The PLA/starch blend was then used as a solid carbon source for biological nitrate removal. The carbon release rate of PLA/starch was found to increase with increased starch content in leaching experiments. PLA/starch at 5:5 mass ratio was found to have the highest denitrification performance and organic carbon consumption efficiency in semi-continuous denitrification experiments, and was also revealed to support complete denitrification at 50 mg-N/L influent nitrate concentration in continuous experiments. The effluent nitrate concentration was <2 mg NO3–-N/L, which met the national standard (GB 14848-93) for groundwater. Scanning electron microscopy results further showed that the surface roughness of PLA/starch increased with prolonged experimental time, which may be conducive to microorganism attachment. Therefore, PLA/starch was a suitable carbon source and biofilm carrier for groundwater remediation.

scholarly journals Performance of the anammox sequencing batch reactor treating synthetic and real landfill leachate

2018 ◽  
Vol 44 ◽  
pp. 00179 ◽  
Author(s):  
Mariusz Tomaszewski ◽  
Grzegorz Cema ◽  
Tomasz Twardowski ◽  
Aleksandra Ziembińska-Buczyńska
Keyword(s):  
Nitrogen Removal ◽  
Landfill Leachate ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Nitrogen Loading ◽  
Synthetic Wastewater ◽  
High Nitrogen ◽  
Removal Capacity ◽  
Anammox Activity ◽  
Anammox Process

The anaerobic ammonium oxidation (anammox) process is one of the most energy efficient and environmentally-friendly bioprocess for the treatment of the wastewater with high nitrogen concentration. The aim of this work was to study the influence of the high nitrogen loading rate (NLR) on the nitrogen removal in the laboratory-scale anammox sequencing batch reactor (SBR), during the shift from the synthetic wastewater to landfill leachate. In both cases with the increase of NLR from 0.5 to 1.1 – 1.2 kg N/m3d, the nitrogen removal rate (NRR) increases to about 1 kg N/m3d, but higher NLR caused substrates accumulation and affects anammox process efficiency. Maximum specific anammox activity was determined as 0.638 g N/g VSSd (NRR 1.023 kg N/m3d) and 0.594 g N/g VSSd (NRR 1.241 kg N/m3d) during synthetic and real wastewater treatment, respectively. Both values are similar and this is probably the nitrogen removal capacity of the used anammox biomass. This indicates, that landfill leachate did not influence the nitrogen removal capacity of the anammox process.

Denitrification of Nitrate-Rich Water Using Entrapped-Mixed-Microbial Cells Immobilization Technique

1992 ◽  
Vol 26 (3-4) ◽  
pp. 923-931 ◽  
Author(s):  
S. Nitisoravut ◽  
P. Y. Yang
Keyword(s):  
Exchange Process ◽  
Nitrate Removal ◽  
Cellulose Triacetate ◽  
Feed Concentration ◽  
Microbial Cells ◽  
Ion Exchange Process ◽  
Alternative Approach ◽  
High Nitrate Concentration ◽  
N Loading ◽  
One Year

A denitrification process was examined by using Entrapped-Mixed-Microbial Cells Immobilization (EMMCI) process. The mixed microbes were entrapped into a polymeric cellulose triacetate. The reactor was operated over one year with feed concentration ranging from 50 to 850 mg NO3-N/l. The hydraulic retention times (HRT) were also varied from 1.8 to 11.3 hours. Complete denitrification was obtained at an HRT of 2.6 to 11.3 hours. At an HRT of 1.8 hours, the maximum nitrate-N loading rate of 591.6 g/m3 ·h (based on carriers volume) was achieved with an 88.3% denitrification efficiency. Under high range of NaHCO3 concentrations from 10 to 20 g/l, the denitrification efficiency above 96% could be obtained. This EMMCI process has showed very promising results in respect to nitrate removal. It can be considered as an alternative approach tor direct treatment of nitrate-rich water or in a combination with an ion exchange process with an intent to eliminate the high nitrate concentration from the spent regenerant.

scholarly journals Experimental Analysis and Modeling of Nitrate Removal through Zero-Valent Magnesium Particles

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1276 ◽  
Author(s):  
Siciliano ◽  
Curcio ◽  
Limonti
Keyword(s):  
Nitrate Concentration ◽  
Nitrate Removal ◽  
Experimental Results ◽  
Process Efficiency ◽  
Main Reaction ◽  
Main Reaction Product ◽  
Nitrogen Forms ◽  
Sustainable Technologies ◽  
Batch Tests ◽  
Effects Of Ph

The pollution of water by nitrates represents an important environmental and health issue. The development of sustainable technologies that are able to efficiently remove this contaminant is a key challenge in the field of wastewater treatment. Chemical denitrification by means of zero-valent metallic elements is an interesting method to reduce the oxidized forms of nitrogen. Compared to other metallic reactants, zero-valent magnesium (ZVM) has many profitable aspects, but its use for nitrate removal has scarcely been investigated. In the present work, several batch tests were conducted to examine the concurrent effects of pH, initial nitrate concentration and Mg0 quantity on process performance. The experimental results proved that at pH 3, for a given initial nitrate concentration, the dose of ZVM largely influences process efficiency. In particular, with a ratio between Mg0 and initial N-NO3− amount (Mg/NNi) of 0.33 g/mg, it is possible to obtain complete denitrification within 30 min. Beyond this ratio, no further improvement of treatment was observed. The experiments allowed us to identify the nitrogen forms produced during the treatment. Nitrogen gas was generally the main reaction product, but the trends of the different compounds (NO3−, NO2−, NH4+ and N2) notably changed in response to the modification of operating parameters. Moreover, the results demonstrated that, in a highly acidic environment, when treating solutions with a low nitrate concentration, process performances are unsatisfactory even when using a high Mg/NNi ratio. By increasing the process pH to 5 and 7, a significant denitrification decline occurred. Furthermore, at these pH levels, the enhancement of nitrate concentration caused a progressive process deterioration. Through detailed analysis of experimental results, reactions kinetics and new mathematical equations, able to describe the trends of different nitrogen forms, have been defined. Moreover, reactions pathways have been proposed. Finally, the characterization of exhausted material allowed us to identify the corrosion products formed during the treatment.

Concurrent increases of PM2.5 and Ozone observed in Seoul, May 2019

2020 ◽  
Author(s):  
Jeewon Son ◽  
Sunggu Kang ◽  
Joo-ae Kim ◽  
Junsu Gil ◽  
Meehye Lee ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Nitrate Concentration ◽  
Heterogeneous Reactions ◽  
Biomass Combustion ◽  
Scanning Mobility Particle Sizer ◽  
High Nitrate Concentration ◽  
The Mean ◽  
Reactive Gases ◽  
Particle Sizer ◽  
Vertical Winds

<p> In Seoul, PM<sub>2.5</sub> concentrations were frequently elevated with O<sub>3</sub> in May 2019. The most abundant constituent of PM<sub>2.5</sub> was nitrate, which was the best correlated with OC (organic carbon) as well as NH<sub>4</sub><sup>+</sup>. An intensive experiment was conducted in the eastern part of Seoul from March 29 to June 19, 2019. Measurement was made for PM<sub>2.5 </sub>and its chemical composition including NO<sub>3</sub><sup>-</sup>, SO<sub>4</sub><sup>2-</sup>, NH<sub>4</sub><sup>+ </sup>, OC, EC (elemental carbon), and reactive gases including O<sub>3</sub>, NO, NO<sub>2</sub>, CO, HONO, HNO<sub>3</sub>, NH<sub>3</sub>, and SO<sub>2</sub>, and meteorological variables including vertical winds and mixed layer height (MLH). The particle number concentration was measured using SMPS (Scanning Mobility Particle Sizer). All measurements were averaged for 1 hour according to the resolution of PM<sub>2.5</sub> chemical composition. For the entire experiment, the mean mass concentrations of PM<sub>2.5</sub>, NO<sub>3</sub><sup>-</sup>, SO<sub>4</sub><sup>2-</sup>, NH<sub>4</sub><sup>+</sup>, OC, and EC were 20.40 μg/m<sup>3</sup>, 4.07 μg/m<sup>3</sup>, 2.62 μg/m<sup>3</sup>, 2.01 μg/m<sup>3</sup>, 4.01 μg/m<sup>3</sup>, and 1.04 μg/m<sup>3</sup>, respectively. For reactive gases, the mean concentration was 1.03 ppbv for HONO, 0.70 ppbv for HNO<sub>3</sub>, 14.87 ppbv for NH<sub>3</sub>, 2.77 ppbv for SO<sub>2</sub>, and 48.79 ppbv for O<sub>3</sub>. </p><p> The maximum PM<sub>2.5</sub> concentration of 72.81 μg/m<sup>3 </sup>was observed under the influence of weak Asian dust event in the end of April. In May, there were three distinct episodes with highly enhanced PM<sub>2.5</sub>. In the early May, the maximum nitrate concentration (36.11 μg/m<sup>3</sup>) was observed with high HONO (2.41 ppbv) on 4 May. In the middle of May, PM<sub>2.5</sub> was raised with SO<sub>4</sub><sup>2-</sup> under stagnant condition. On 25 May, PM<sub>2.5</sub> was raised up to 92 μg/m<sup>3 </sup>with high nitrate concentration (18.56 μg/m<sup>3</sup>) , when O<sub>3</sub> reached 205 ppbv. In this episode, O<sub>3</sub> concentration remained around 90 ppbv at night and OC and EC were well correlated with highly enhanced K<sup>+</sup>. Thus, the concurrent enhancement of PM<sub>2.5</sub> and O<sub>3</sub> was likely due to the influence of aged biomass combustion plume laden air transported from southeast China. At the same time, HNO<sub>3</sub> and HONO concentration was highly elevated, indicating that heterogeneous reactions played a role.</p>

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