Effect of carbon source and nitrate concentration on denitrification of high-nitrate wastewater

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.

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Nitrate Removal of Fluidized-Bed Biofilm Reactors Using Starch / Polyvinyl Alcohol Blends as Carbon Source and Carrier Simultaneously at Low Temperature

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.501-504.2089 ◽

2014 ◽

Vol 501-504 ◽

pp. 2089-2092

Author(s):

Hai Hong Zhou ◽

Fang He

Keyword(s):

Drinking Water ◽

Controlled Release ◽

Low Temperature ◽

Carbon Source ◽

Polyvinyl Alcohol ◽

Fluidized Bed ◽

Nitrate Concentration ◽

Nitrate Removal ◽

Biofilm Reactors ◽

Resident Time

A kind of controlled-release carbon source, starch / polyvinyl alcohol blends (SPVA), was used as both carbon source and biofilm supporter in laboratory-scale fluidized-bed biofilm reactors (FBBRs) to remove nitrate from groundwater. Results show: when the influent nitrate concentration was 100 mg-N /L, FBBRs packed with SPVA can effectively remove nitrate from groundwater at the condition of temperature 20 °C, hydraulic resident time (HRT) 4 h. The effluent nitrate can meet with the Chinese drinking water standards at low temperature (15-2 °C) by adjusted the HRT of FBBRs. The denitrification rate declined nonlinearly with the decrease of temperature and changed sharply in the range of 20-15 °Cand 10-5 °C.

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Influence of ORP variation, carbon source and nitrate concentration on denitrifying phosphorus removal by DPB sludge from dephanox process

Water Science & Technology ◽

10.2166/wst.2004.0632 ◽

2004 ◽

Vol 50 (10) ◽

pp. 153-161 ◽

Cited By ~ 9

Author(s):

Y.Y. Wang ◽

Y.Z. Peng ◽

C.Y. Peng ◽

S.Y. Wang ◽

W. Zeng

Keyword(s):

Carbon Source ◽

Phosphorus Removal ◽

Turning Point ◽

Nitrate Concentration ◽

Phosphorus Uptake ◽

Phosphorus Release ◽

Denitrifying Phosphorus Removal ◽

External Carbon Source ◽

High Nitrate Concentration ◽

On Line

The effect of added carbon source and nitrate concentration on the denitrifying phosphorus removal by denitrifying phosphorus removal bacteria sludge was systematically studied using batch experiments, at the same time the variation of ORP was investigated. Results showed that the denitrifying and phosphorus uptake rate in the anoxic phase increased with the high initial anaerobic carbon source addition. However, once the initial COD concentration reached a certain level, which was in excess of the PHB saturation of Poly-p bacteria, residual COD carried over to the anoxic phase inhibited the subsequent denitrifying phosphorus uptake. This was equal to supplementing the external carbon source to the anoxic phase, furthermore the higher the external carbon source concentration the more powerful the inhibition caused. High nitrate concentration in the anoxic phase increased the initial denitrifying phosphorus rate. Once the nitrate was exhausted, phosphate uptake changed to phosphate release. Moreover, the time of this turning point occurred later with the higher nitrate addition. On the other hand, through on-line monitoring the variation of the ORP with different initial COD concentration, it was found that ORP could be used as a control parameter for phosphorus release, but it is impossible to utilize ORP for controlling the dinitrification and anoxic phosphorus uptake operations.

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Effect of Nitrate on Inducement of Denitrifying Phosphate-Accumulating Organisms

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.864-867.201 ◽

2013 ◽

Vol 864-867 ◽

pp. 201-204

Author(s):

Li Qing Zhang ◽

Gang Zhang

Keyword(s):

Carbon Source ◽

Linear Relationship ◽

Removal Efficiency ◽

Uptake Rate ◽

Nitrate Concentration ◽

Phosphorus Uptake ◽

Phosphorus Release ◽

Anoxic Condition ◽

Batch Experiments ◽

Nitrate Consumption

Denitrifying phosphate accumulating (DNPA) was investigated by controlling the concentration of nitrate in anoxic stage with batch experiments. A linear relationship between the quantity of phosphorus uptaken and the consumption of nitrate was shown under anoxic condition with the same concentration of carbon source. Based on the slope of the line between phosphorus release quantity and nitrate consumption, nitrate concentration was adjusted in the anoxic stage. Excellent DNPA performance had been achieved rapidly. The removal efficiency of phosphorus was above 95%, and nitrate more than 96%. According to the maximum phosphorus uptake rate of anoxic or aerobic, it was calculated that the percent of DNPAOs to PAOs was increased from 22% to 79% after cultivation.

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An/OSBR Process for Phosphorus Removal Effect of Different Sludge Load and Nitrate Concentration Condition

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.864-867.1886 ◽

2013 ◽

Vol 864-867 ◽

pp. 1886-1889

Author(s):

Xiao Yan Tian ◽

Liang Wang

Keyword(s):

Carbon Source ◽

Linear Relationship ◽

Phosphorus Removal ◽

Nitrate Concentration ◽

Phosphorus Concentration ◽

Biological Phosphorus Removal ◽

Nitrate Concentrations ◽

Biological Phosphorus ◽

Anaerobic Reaction ◽

Concentration Condition

Based on An / OSBR, the paper explores the different sludge loading and nitrate concentrations under the conditions of An / OSBR effects of biological phosphorus removal systems.The influent phosphorus concentration constant at 10 ± 0.5mg / L, in order to compare the end of the anaerobic and effluent TP concentration.The results showed that: ①With the increasing of nitrate concentrations , PAOs release phosphorus in the anaerobic reaction zone is decreased, nitrate appears to reduce the synthesis of PHB, which is due to PHB synthesis and denitrification requires a simple carbon source as hydrogen donor, resulting in competition;② With the COD sludge load increases, the effluent TP concentration decreased, when the COD sludge load ≥ 0.46mgCOD/mgMLSS · d, the effluent TP concentrations is less than 1mg / L;③ When the reaction temperature was 25 °C and 15 °C , the releasing phosphorus in anaerobic and COD sludge load have a good correlation,Linear relationship between the two were: y = 0.72 +71.91 x ( 25 °C), y = 2.81 +73.33 x (15 °C);

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Effects of Nitrate Concentration on Heterotrophic Denitrification in Wastewater Using Poly (Butylene Succinate) as a Carbon Source and Carrier

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.665.469 ◽

2014 ◽

Vol 665 ◽

pp. 469-478

Author(s):

Guo Zhi Luo ◽

Wen Jing Sun ◽

Qian Liu ◽

Yu Hu ◽

Hong Xin Tan

Keyword(s):

Carbon Source ◽

Nitrate Nitrogen ◽

Nitrate Concentration ◽

Morphological Changes ◽

Carbon Sources ◽

High Concentration ◽

Butylene Succinate ◽

Weight Losses ◽

Biofilm Carrier ◽

Heterotrophic Denitrification

Biodegradable polymer pellets (BDPs) can act as biofilm carrier and as water insoluble carbon source for denitrification simultaneously, which is accessible only by enzymatic attack. It is expected that organic carbon source for heterotrophic denitrification by using BDPs will not be overdose or shortage. The current batch experiment was conducted to examine if the PBS would supply enough carbon source to the denitrification with high concentration nitrate. The initial nitrate nitrogen (NO3--N) concentrations were 100 mg NO3-N/l (T1), 300 mg NO3-N/l (T2) and 500 mg NO3-N/l (T3) respectively. The results showed that the initial nitrate concentrations have significant effects on the removal of nitrate nitrogen and total nitrogen (TN) using PBS as carbon source. The efficiencies of removal of nitrate and TN in T1 were almost 100%. The amounts of NO3--N and TN that were removed in T2 were 286.60±6.66 mg NO3-N/g PBS (in dry wt), which was significantly higher than that of T1 and T3. Accumulation of ammonium and nitrite were observed in T2 and T3. The morphological changes and the weight losses observed for PBS granules indicated that good degradation occurred in static denitrification environments. But the insufficient of carbon sources for denitrification in T2 and T3 was observed.

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Morphological Characterization of Mycobacteriophage R1

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100051281 ◽

1974 ◽

Vol 32 ◽

pp. 254-255

Author(s):

B. L. Soloff ◽

T. A. Rado

Keyword(s):

Carbon Source ◽

Stationary Phase ◽

Growth Phase ◽

Minimal Medium ◽

Morphological Characterization ◽

Logarithmic Growth Phase ◽

Complete Lysis ◽

Lysogenic Culture ◽

Logarithmic Growth

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.

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