Comparative Analysis of Nitrate Removal in Sub-Surface Flow Constructed Wetlands by Different External Carbon Sources

2014 ◽  
Vol 1073-1076 ◽  
pp. 779-783
Author(s):  
Patience Awhavbera ◽  
Lian Fang Zhao
Keyword(s):  
Carbon Source ◽  
Wheat Straw ◽  
Constructed Wetlands ◽  
Nitrate Removal ◽  
Waste Product ◽  
Carbon Sources ◽  
Surface Flow ◽  
Synthetic Wastewater ◽  
External Carbon Source ◽  
N Removal

External carbon sources provide additional nutrients that improve the efficiency of nitrate removal in constructed wetlands. Typha angustifolia L. were planted in four vertical subsurface-flow constructed wetlands. Different external carbon sources were fed into the columns, to investigate and compare their treatment of nitrate in synthetic wastewater, with initial influent C/N ratio of 1:1. Wetland A (WA) with 50g wheat straw as external carbon source, wetland B (WB) with 50g woodchips, wetland C (WC) with additional 10mg/L glucose and wetland D (WD) without external carbon source to serve as the control, were used in the lab-scale experimental study. WA, WB, WC and WD within a period of 24 days, cumulatively removed 109.38mg/L, 93.75mg/L, 85.14mg/L, and 64.01mg/L nitrate, respectively, from the influent. The nitrate-nitrogen (NO3–N) removal efficiency as aided by the external carbon sources was in the order: wheat straw > woodchips > glucose > control. Wheat straw treated 93% NO3–N, woodchips 78%, glucose 72% and the control 53%. The results indicate that WA, WB and WC outperformed the control system, due to the additional carbon sources. In general, the wheat straw had a better performance than wood chips and glucose. Thus, wheat straw as low cost biological waste product is recommended for the treatment of nitrate in wetlands.

scholarly journals Methane Emissions Driven by Adding a Gradient of Ethanol as Carbon Source in Integrated Vertical-Flow Constructed Wetlands

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 1086
Author(s):  
Xiaoling Liu ◽  
Jingting Wang ◽  
Xiaoying Fu ◽  
Hongbing Luo ◽  
Bruce C. Anderson ◽  
...  
Keyword(s):  
Carbon Source ◽  
Constructed Wetlands ◽  
Control Experiment ◽  
Ethanol Concentration ◽  
Removal Rate ◽  
Carbon Sources ◽  
Vertical Flow ◽  
Emission Flux ◽  
Rate Range ◽  
External Carbon Source

This work aims to investigate the methane emissions from integrated vertical-flow constructed wetlands (IVCWs) when ethanol is added as an external carbon source. In this study, a gradient of ethanol (0, 2, 4, 8, 16 and 32 mmol/L) was added as the carbon source in an IVCW planted with Cyperus alternifolius L. The results showed that the methane emission flux at an ethanol concentration of 32 mmol/L was 32.34 g CH4 m−2 day−1 less than that of the control experiment (0 mmol/L) and that the methane emission flux at an ethanol concentration of 16 mmol/L was 5.53 g CH4 m−2 day−1 less than that at 0 mmol/L. In addition, variations in the water quality driven by the different ethanol concentrations were found, with a redox potential range of −64 mV to +30 mV, a pH range of 6.6–6.9, a chemical oxygen demand (COD) removal rate range of 41% to 78%, and an ammonia nitrogen removal rate range of 59% to 82% after the ethanol addition. With the average CH4-C/TOC (%) value of 35% driven by ethanol, it will be beneficial to understand that CH4-C/TOC can be considered an ecological indicator of anthropogenic methanogenesis from treatment wetlands when driven by carbon sources or carbon loading. It can be concluded that adding ethanol as an external carbon source can not only meet the water quality demand of the IVCW treatment system but also stimulate and increase the average CH4 emissions from IVCWs by 23% compared with the control experiment. This finding indicates that an external carbon source can stimulate more CH4 emissions from IVCWs and shows the importance of carbon sources during sewage treatment processes when considering greenhouse emissions from treated wetlands.

Behavior of solid carbon sources for biological denitrification in groundwater remediation

2012 ◽  
Vol 65 (9) ◽  
pp. 1696-1704 ◽  
Author(s):  
Jianmei Zhang ◽  
Chuanping Feng ◽  
Siqi Hong ◽  
Huiling Hao ◽  
Yingnan Yang
Keyword(s):  
Carbon Source ◽  
Wheat Straw ◽  
Groundwater Remediation ◽  
Nitrate Removal ◽  
Carbon Sources ◽  
Batch Experiments ◽  
Denitrification Activity ◽  
Leaching Experiments ◽  
Potential Carbon ◽  
Stimulation Of

The present study was conducted to compare the behavior of wheat straw, sawdust and biodegradable plastic (BP) as potential carbon sources for denitrification in groundwater remediation. The results showed that a greater amount of nitrogen compounds were released from wheat straw and sawdust than from BP in leaching experiments. In batch experiments, BP showed higher nitrate removal efficiency and longer service life than wheat straw and sawdust, which illustrated that BP is the most appropriate carbon source for stimulation of denitrification activity. In column experiments, BP was able to support complete denitrification at influent nitrate concentrations of 50, 60, 70, 80, and 90 mg NO3−-N/L, showing corresponding denitrification rates of 0.12, 0.14, 0.17, 0.19, and 0.22 mg NO3−-N.L−1.d−1.g−1, respectively. These findings indicate that BP is applicable for use as a carbon source for nitrate-polluted groundwater remediation.

Advances of External Carbon Source in Denitrification

2012 ◽  
Vol 518-523 ◽  
pp. 2319-2323 ◽  
Author(s):  
Guang Ying Liu ◽  
Huan Zhen Zhang ◽  
Wei Li ◽  
Xin Zhang
Keyword(s):  
Carbon Source ◽  
Slow Release ◽  
Removal Rate ◽  
Nitrate Removal ◽  
Carbon Sources ◽  
Electron Donors ◽  
Primary Sludge ◽  
External Carbon Source ◽  
The Media ◽  
Available Carbon

Carbon source used as electron donors is critical to heterotrophic denitrification. Addition of external carbon source is necessary when internal organics are deficient. A review was conducted on the use of external carbon source in denitrification. Traditional carbon sources such as methanol and ethanol, alternative carbon sources such as cellulose-rich materials, biodegradable polymers and primary sludge are included in external carbon sources. Present situation and problems of its biodegradability and effects in denitrification are summarized. Focus in external carbon source includes further study on the biodegradation mechanism of the media, slow release performance and nitrate removal rate of available carbon source and continuous research on new kinds of substrates. Recommendations on further study of carbon source are put forward.

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.

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.

Substrate Organic Matter to Improve Nitrate Removal in Surface-Flow Constructed Wetlands

2007 ◽  
Vol 36 (1) ◽  
pp. 194-207 ◽  
Author(s):  
Michael R. Burchell ◽  
R. Wayne Skaggs ◽  
Charles R. Lee ◽  
Steven Broome ◽  
George M. Chescheir ◽  
...  
Keyword(s):  
Organic Matter ◽  
Constructed Wetlands ◽  
Nitrate Removal ◽  
Surface Flow ◽  
Surface Flow Constructed Wetlands

Biological denitrification of drinking water using various natural organic solid substrates

2004 ◽  
Vol 48 (11-12) ◽  
pp. 489-495 ◽  
Author(s):  
S. Aslan ◽  
A. Türkman
Keyword(s):  
Drinking Water ◽  
Carbon Source ◽  
Wheat Straw ◽  
Nitrate Removal ◽  
Solid Particles ◽  
Effluent Water ◽  
Activated Carbon Adsorption ◽  
Organic Solid ◽  
Solid Substrates ◽  
Laboratory Reactor

Denitrification of drinking water was studied using various natural organic solid substrates (NOSS) such as poplar, hornbeam, pine shavings and wheat straw as a carbon source in a batch unit. The highest nitrate removal efficiency was observed with the wheat straw, so it was chosen as the carbon source for biodenitrification in an upflow laboratory reactor. In order to remove solid particles from the effluent water, a sand filter unit was placed after the denitrification reactor. The soluble DOC contents in the reactor affected the efficiency of nitrate elimination and nitrate concentration of the effluent water remained below acceptable values (50 mg/l NO3-). In order to remove colour, DOC and nitrate from the water, powdered activated carbon adsorption studies were performed in the batch unit.

Enhanced Heterotrophic Denitrification for the Treatment of Nitrate Contaminated Groundwater by Wheat Straw

2013 ◽  
Vol 316-317 ◽  
pp. 625-628
Author(s):  
Jian Mei Zhang ◽  
Chuan Ping Feng ◽  
Si Qi Hong ◽  
Hui Ling Hao
Keyword(s):  
Carbon Source ◽  
Wheat Straw ◽  
Carbon Sources ◽  
Complete Removal ◽  
Contaminated Groundwater ◽  
Column Experiments ◽  
Inlet Concentration ◽  
Reducing Conditions ◽  
Organic Carbon Sources ◽  
Heterotrophic Denitrification

The method of the heterotrophic denitrification remediation of nitrate-polluted groundwater involves the study of organic carbon sources as electron donor. The aim of the present study was to evaluate wheat straw for its ability to enhance denitrification in column experiments. The inlet concentration was 50.0 mgNO3--N/L and the column operated at the flow rate of 2.0 ml/min. The result showed that in the presence of wheat straw, highly reducing conditions were generated and complete removal of nitrate (>95%) was achieved, with less accumulation of nitrite. Consequently, wheat straw is an attractive carbon source for groundwater denitrification.

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