Nitrate removal using different carbon substrates in a laboratory model

2011 ◽  
Vol 63 (11) ◽  
pp. 2700-2706 ◽  
Author(s):  
Seyyed Ebrahim Hashemi ◽  
Manouchehr Heidarpour ◽  
Behrouz Mostafazadeh-Fard
Keyword(s):  
Date Palm ◽  
Nitrate Concentration ◽  
Nitrate Removal ◽  
Carbon Sources ◽  
Water Velocity ◽  
Barley Straw ◽  
Laboratory Model ◽  
Rice Husks ◽  
Carbon Supply ◽  
Palm Leaf

Agricultural fields have been frequently identified as major contributors of nitrate leaching into surface and ground waters. Tile drains can act as direct pathways, transferring leached nitrate to surface water. Bioreactor filters are useful for the removal of nitrate from drainage waters; however, these filters require an external carbon supply to sustain denitrification. In this study, four organic carbon sources including wood, barley straw, rice husks, and date palm leaf, were used to enhance denitrification and the effects of water velocity and influent nitrate concentration on the nitrate removal were evaluated. Cumulative nitrate removal was highest for the date palm leaf treatments and was lowest for the wood treatments. The effects were in decreasing order for date palm leaf, barley straw, rice husks, and wood, respectively. The performance of the biofilters improved with increasing influent nitrate concentration and decreasing water velocity, allowing for high nitrate removal rates to be achieved. The results showed that all of the treatments had reduced the effluent nitrate concentrations below the USEPA maximum contaminant level for drinking water of 45 mg L−1 nitrate at the end of the study.

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 Khalasa Date Palm Leaf Fiber as a Potential Reinforcement for Polymeric Composite Materials

2020 ◽  
pp. 113501
Author(s):  
Elsadig Mahdi ◽  
Daniel R. Hernández Ochoa ◽  
Ashkan Vaziri ◽  
Aamir Dean ◽  
Murat Kucukvar
Keyword(s):  
Composite Materials ◽  
Date Palm ◽  
Polymeric Composite ◽  
Polymeric Composite Materials ◽  
Palm Leaf ◽  
Leaf Fiber

Nitrate Removal of Drainage Water with Barley Straw as a Bioreactor Filter

2010 ◽  
Author(s):  
Seyyed Ebrahim Hashemi ◽  
Manouchehr Heidarpour ◽  
Behrouz Mostafazadeh-Fard ◽  
Ali Madani ◽  
Sayed-Farhad Mousavi ◽  
...  
Keyword(s):  
Nitrate Removal ◽  
Drainage Water ◽  
Barley Straw

The vulnerability of Arctic shelf sediments to climate change

2015 ◽  
Vol 23 (4) ◽  
pp. 461-479 ◽  
Author(s):  
Robie W. Macdonald ◽  
Zou Zou A. Kuzyk ◽  
Sophia C. Johannessen
Keyword(s):  
Organic Carbon ◽  
Carbon Sources ◽  
The Arctic ◽  
Sedimentary Environments ◽  
Carbon Supply ◽  
Shelf Sediment ◽  
Wide Range ◽  
Metabolic Conditions ◽  
Shelf Sediments ◽  
Ocean Ecosystem

The sediments of the pan-Arctic shelves contribute an important component to the Arctic Ocean ecosystem by providing a habitat for biota (benthos), a repository for organic and inorganic non-conservative substances entering or produced within the ocean, a reactor and source of transformed substances back to the water column, and a mechanism of burial. Sediments interact with ice, ocean, and the surrounding land over a wide range of space and time scales. We discuss the vulnerability of shelf sediment to changes in (i) organic carbon sources, (ii) pathways of sediment and organic carbon supply, and (iii) physical and biogeochemical alteration (diagenesis). Sedimentary environments of the shelves and basins are likely to exhibit a wide variance in their response to global change because of their wide variation in sediment sources, processes, and metabolic conditions. In particular, the Chukchi and Barents shelves are dominated by inflowing waters from oceans to the south, whereas the interior shelves are more closely tied to terrigenous sources due to river inflow and coastal erosion.

Nitrate removal using Brevundimonas diminuta MTCC 8486 from ground water

2009 ◽  
Vol 60 (2) ◽  
pp. 517-524 ◽  
Author(s):  
S. Kavitha ◽  
R. Selvakumar ◽  
M. Sathishkumar ◽  
K. Swaminathan ◽  
P. Lakshmanaperumalsamy ◽  
...  
Keyword(s):  
Carbon Source ◽  
Ground Water ◽  
Nitrate Removal ◽  
Carbon Sources ◽  
Treatment Plant ◽  
Growth Conditions ◽  
Pilot Scale ◽  
Biological Removal ◽  
Treatment Processes ◽  
Brevundimonas Diminuta

Brevundimonas diminuta MTCC 8486, isolated from marine soil of coastal area of Trivandrum, Kerala, was used for biological removal of nitrate from ground water collected from Kar village of Pali district, Rajasthan. The organism was found to be resistance for nitrate up to 10,000 mg L−1. The optimum growth conditions for biological removal of nitrate were established in batch culture. The effect of carbon sources on nitrate removal was investigated using mineral salt medium (MSM) containing 500 mg L−1 of nitrate to select the most effective carbon source. Among glucose and starch as carbon source, glucose at 1% concentration increased the growth (182±8.24 × 104 CFU mL−1) and induced maximum nitrate reduction (86.4%) at 72 h. The ground water collected from Kar village, Pali district of Rajasthan containing 460±5.92 mg L−1 of nitrate was subjected to three different treatment processes in pilot scale (T1 to T3). Higher removal of nitrate was observed in T2 process (88%) supplemented with 1% glucose. The system was scaled up to 10 L pilot scale treatment plant. At 72 h the nitrate removal was observed to be 95% in pilot scale plant. The residual nitrate level (23±0.41 mg L−1) in pilot scale treatment process was found to be below the permissible limit of WHO.

The effect of water velocity on nitrate removal in vegetated waterways

2018 ◽  
Vol 215 ◽  
pp. 230-238 ◽  
Author(s):  
Giuseppe Castaldelli ◽  
Vassilis Aschonitis ◽  
Fabio Vincenzi ◽  
Elisa Anna Fano ◽  
Elisa Soana
Keyword(s):  
Nitrate Removal ◽  
Water Velocity ◽  
Effect Of Water

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.

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