Biological Filters for Post-Denitrification

1993 ◽  
Vol 27 (5-6) ◽  
pp. 369-379 ◽  
Author(s):  
Svend-Erik Jepsen ◽  
Jes la Cour Jansen
Keyword(s):  
Carbon Source ◽  
Wastewater Treatment Plants ◽  
Removal Rate ◽  
Head Loss ◽  
Slow Increase ◽  
Loading Rates ◽  
Carrier Material ◽  
External Carbon Source ◽  
Removal Capacity ◽  
Biological Filters

Nitrifying wastewater treatment plants exist in many European countries. These plants can be extended for Total-Nitrogen removal by a post-denitrification stage using an external carbon source. A compact solution for this process is submerged biological filters. Two pilot plants have been used as post-denitrification reactors, a down-flow filter with expanded slate as carrier material (Biocarbone) and an up-flow filter with polystyrene pellets as carrier material (Biostyr). Nitrified wastewater was treated to a stable effluent quality from both pilot plants to below the Danish effluent standard which is 8 mg Tot-N/l. The pilot plants have been operated at different loading rates with acetate as external carbon source. Stable removal with effluent nitrate less than 5 mg NO3-N/l was obtained for loading rates up to more than 4 kg NO3-N/m3 d at 10-17°C. The removal capacity of the pilot plants has been shown to be independent of time from last backwash. The removal rate over different sections of the filters does not change within one operation cycle. The backwash removes the excess biomass and particles which cause the head loss, but the removal capacity remains in the filter. The head loss development in the two systems is quite different. In the Biostyr system, the head loss raises close to linear with time (load), while the Biocarbone shows slow increase in head loss with time until the surface is clogged by incoming particles and biomass growth. When this occurs, the nitrogen bubbles, which are produced in the lower part of the filter, are trapped just below the top layer. The void volume of the filter is occupied by nitrogen gas and the head loss increases very fast to the terminal head loss. This investigation has shown that both kinds of submerged filters are capable to serve as post-denitrification reactors to remove nitrate to the most stringent effluent standards.

scholarly journals Optimizing external carbon source addition in domestics wastewater treatment based on online sensoring data and a numerical model

2017 ◽  
Vol 75 (11) ◽  
pp. 2716-2725 ◽  
Author(s):  
Qibin Wang ◽  
Qiuwen Chen ◽  
Jing Chen
Keyword(s):  
Wastewater Treatment ◽  
Numerical Model ◽  
Carbon Source ◽  
Wastewater Treatment Plants ◽  
Pilot Scale ◽  
Fixed Dose ◽  
Carbon Addition ◽  
External Carbon Source ◽  
Wastewater Quality ◽  
Denitrification Reactor

The removal of total nitrogen in wastewater treatment plants (WWTPs) is often unsatisfactory for a variety of reasons. One possible measure to improve nitrogen removal is the addition of external carbon. However, the amount of carbon addition is directly related to WWTP operation costs, highlighting the importance of accurately determining the amount of external carbon required. The objective of this study was to obtain a low nitrate concentration in the anoxic zone of WWTPs efficiently and economically by optimizing the external carbon source dosage. Experiments were conducted using a pilot-scale pre-denitrification reactor at a Nanjing WWTP in China. External carbon source addition based on online monitoring of influent wastewater quality and a developed nitrification–denitrification numerical model was investigated. Results showed that carbon addition was reduced by 47.7% and aeration costs were reduced by 8.0% compared with those using a fixed-dose addition mode in the pilot reactor. The obtained technology was applied to the full-scale Jiangxinzhou WWTP in Nanjing with promising results.

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.

scholarly journals Enhance nitrogen removal in bioretention cells with addition of hydrothermal pre-treated pine barks as external carbon source

2021 ◽  
Author(s):  
Jing Tuo ◽  
Shiwei Cao ◽  
Muzi Li ◽  
Rong Guo
Keyword(s):  
Carbon Source ◽  
Nitrogen Removal ◽  
Removal Rate ◽  
Common Factor ◽  
Nutrients Removal ◽  
Fiber Structure ◽  
Effluent Quality ◽  
External Carbon Source ◽  
Carbon Release ◽  
Cod Removal Rate

Abstract The problem of poor carbon source is a common factor limiting the nutrients removal in bioretention cells (BRCs). This study aimed to investigate the feasibility of using modified biomass in BRCs filled with a mixture of fly ash ceramsite and pumice fillers to enhance nitrogen removal. Different pretreatment methods (hydrothermal-treated, acid-treated and alkali-treated) were attempted, and hydrothermal pretreatment showed a best performance in carbon release ability. The scanning electron microscopy showed that the lignin in hydrothermal pretreated pine barks (H-PBs) was destroyed, and the fiber structure became thinner with more irregular folds, which improved the accessibility of cellulose and attachment of microorganisms. The addition of H-PBs significantly enhanced the nutrients removal in BRCs, and the removal rates of TN and NO3−-N increased by 23.25% and 38.22% compared with those in BRC-A (without external carbon source), but the removal rate of NH4+-N was inferior to BRC-A. Besides, the large carbon release amount of H-PBs did not deteriorate the effluent quality, with COD removal rate of 87.98% in the 48 d. These results indicate that the BRCs by adding H-PBs could intensify the denitrification process.

Iterative design of a nitrate controller using an external carbon source in an activated sludge process

1998 ◽  
Vol 37 (12) ◽  
pp. 95-102 ◽  
Author(s):  
Pericles R. Barros ◽  
Bengt Carlsson
Keyword(s):  
Carbon Source ◽  
Activated Sludge ◽  
High Performance ◽  
Controller Design ◽  
Wastewater Treatment Plants ◽  
Design Procedure ◽  
Pole Placement ◽  
Activated Sludge Process ◽  
Suggested Approach ◽  
External Carbon Source

More stringent effluent and cost requirements are increasing the need for better control of wastewater treatment plants. In an activated sludge process, the nitrogen removal efficiency may be improved by adding an external carbon source. In this paper, automatic control of the nitrate level by regulating external carbon flow is discussed. More specifically, an iterative tuning procedure for the controller is outlined. Iterative controller design schemes aim at tuning high performance controllers of low complexity using closed loop data. The basic strategy used in this paper is an iterative pole placement controller design procedure. The suggested approach is compared with conventional design in a simulation study.

Effect of full and partial-bed configuration on carbon removal performance of biological aerated filters

2008 ◽  
Vol 58 (5) ◽  
pp. 977-983 ◽  
Author(s):  
Fatihah Suja ◽  
Tom Donnelly
Keyword(s):  
Comparative Study ◽  
Removal Rate ◽  
Organic Loading ◽  
Carbon Removal ◽  
Loading Rates ◽  
Removal Capacity ◽  
Organic Removal ◽  
Biomass Loss ◽  
The Masses

A comparative study to explore the characteristics of partially and fully packed biological aerated filters (BAFs) in the removal of carbon pollutant, reveals that the partial-bed reactor can perform comparably well with the full-bed reactor. The organic removal rate was 5.34 kg COD m−3 d−1 at Organic Loading Rates (OLR) 5.80±0.31 kg COD m−3 d−1 for the full-bed, and 5.22 kg COD m−3 d−1 at OLR 5.79±0.29 kg COD m−3 d−1 for the partial-bed. In the partial-bed system, where the masses of biomass were only 41–51% of those of the full-bed, the maximum carbon removal limit was still between 5 to 6 kg COD m−3 d−1. At organic loadings above 5.0 kg COD m−3 d−1, the carbon removal capacity in both systems was limited by the mass and activity of microorganisms. The SRT in the full and partial-bed reactors was primarily controlled by the biomass loss in the effluent and during backwash operation. The SRT was reduced from 20.08 days at OLR 4.18±0.20 kg COD m−3 d−1 to 7.62 days at OLR 5.80±0.31 kg COD m−3 d−1 in the full-bed, and from 7.17 days to 4.21 days in the partial-bed. After all, SRT values in the partial-bed were always lower than those in the full-bed.

scholarly journals Magnetic Fe3O4-Ag0 Nanocomposites for Effective Mercury Removal from Water

2020 ◽  
Vol 12 (13) ◽  
pp. 5489
Author(s):  
Vassilis J. Inglezakis ◽  
Aliya Kurbanova ◽  
Anara Molkenova ◽  
Antonis A. Zorpas ◽  
Timur Sh. Atabaev
Keyword(s):  
Solid Phase ◽  
Removal Rate ◽  
Average Diameter ◽  
Synthesis Process ◽  
Metallic Silver ◽  
Green Method ◽  
Slow Increase ◽  
Fast Kinetics ◽  
Removal Capacity ◽  
Magnetic Fe3o4

In this study, magnetic Fe3O4 particles and Fe3O4-Ag0 nanocomposites were prepared by a facile and green method, fully characterized and used for the removal of Hg2+ from water. Characterizations showed that the Fe3O4 particles are quasi-spherical with an average diameter of 217 nm and metallic silver nanoparticles formed on the surface with a size of 23–41 nm. The initial Hg2+ removal rate was very fast followed by a slow increase and the maximum solid phase loading was 71.3 mg/g for the Fe3O4-Ag0 and 28 mg/g for the bare Fe3O4. The removal mechanism is complex, involving Hg2+ adsorption and reduction, Fe2+ and Ag0 oxidation accompanied with reactions of Cl− with Hg+ and Ag+. The facile and green synthesis process, the fast kinetics and high removal capacity and the possibility of magnetic separation make Fe3O4-Ag0 nanocomposites attractive materials for the removal of Hg2+ from water.

Slow-Release Carbon Source Composite Materials’ Preparation and Used for Denitrification in Groundwater

2013 ◽  
Vol 658 ◽  
pp. 217-222
Author(s):  
Fan Yang ◽  
He Li Wang
Keyword(s):  
Composite Materials ◽  
Carbon Source ◽  
Organic Carbon ◽  
Slow Release ◽  
Removal Rate ◽  
Nitrate Pollution ◽  
Carrier Material ◽  
N Level ◽  
N Removal ◽  
Organic Carbon Source

Four kinds of slow-release carbon source composite materials were prepared and used as carbon source and biofilm attachment carrier for groundwater nitrate pollution bioremediation. Their performances were detected through static and continuous experiments. The results showed that: In the static experiments, HB20 and HB40 had general release carbon ability, their CODMn were 5.42 and 12.83 mg/L respectively; In the continuous experiments, NO3-N removal rate of HLE decreased from 57.9% to 13.1% within 30 days, the denitrification endurance was not good. Organic carbon source can be released continuously by HBE which had the best denitrifying effect. In the operation of 66 days, above 96.0% NO3-N was removed and NO2-N level was below 0.02mg/L when influent NO3-N =30.0mg/L and HRT=24h. HBE was the most suitable carbon source carrier material which was used in groundwater nitrate pollution bioremediation.

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.

scholarly journals Assessment of brewery wastewater treatment by an attached growth bioreactor

2020 ◽  
Vol 3 (1) ◽  
pp. 32-45
Author(s):  
Jack Budgen ◽  
Pierre Le-Clech
Keyword(s):  
Wastewater Treatment ◽  
Heterotrophic Bacteria ◽  
Treatment Time ◽  
Wastewater Treatment Plants ◽  
Removal Rate ◽  
New Technology ◽  
Brewery Wastewater ◽  
Attached Growth ◽  
Loading Rates ◽  
Craft Beer

Abstract Craft beer is a rapidly growing market globally, placing an increased burden on wastewater treatment plants. To avoid discharge fees, new technology is required to make the on-site treatment of brewery wastewater affordable. This study assessed the application of a novel attached growth bioreactor (AGBR) to treat brewery wastewater to a discharge target (1,500 mg sCOD/L). Specifically, the impacts of the single-pass residence time (HRTsingle-pass), organic loading and media height were investigated. A HRTsingle-pass of 67 min demonstrated the shortest required time to meet the discharge target and the lowest final effluent concentration after 120 hr treatment time. Long HRTsingle-pass demonstrated slower biomass development, while smaller HRTsingle-pass caused an earlier rise in dissolved oxygen (DO) which hindered organic removal by heterotrophic bacteria. The sCOD removal rate increased with loading rates, however plateaued at 65 g sCOD/m2/day for loading rates above 300 g sCOD/m2/day. The media became flooded with biomass for feed strengths above 6.0 g sCOD/L. Greater media height provided additional surface area for biomass development, but marginally decreased the sCOD removal rate (g/m2/day) due to an earlier introduction of DO. Power consumption and footprint considerations found the greater media height to be the preferred choice for breweries.

Treatment of wastewater containing high phenol concentrations using stabilisation ponds enriched with activated sludge

2005 ◽  
Vol 51 (12) ◽  
pp. 257-260 ◽  
Author(s):  
M.S. Ramos ◽  
J.L. Dávila ◽  
F. Esparza ◽  
F. Thalasso ◽  
J. Alba ◽  
...  
Keyword(s):  
Carbon Source ◽  
Activated Sludge ◽  
Sole Carbon Source ◽  
Removal Rate ◽  
Phenol Removal ◽  
Removal Rates ◽  
Loading Rates ◽  
Waste Stabilisation Ponds ◽  
Maximum Value ◽  
Removal Efficiencies

Treatment of wastewater containing high phenol concentrations (up to 4,000 mg/l, 1,600 kg/ha.d) in laboratory-scale stabilisation ponds enriched with activated sludge was studied. Phenol was biodegraded efficiently, even when fed as the sole carbon source. At influent concentrations of 1,000, 1,300, 1,600, 1,900, 2,500, 3,000 and 4,000 mg/l of phenol (loading rates of 400, 520, 640, 760, 1,000, 1,200 and 1,600 kg phenol/ha.d), the phenol removal efficiencies were 92, 89, 81, 81, 76, 65 and 22%, respectively. At 4,000 mg/l of phenol, the enriched ponds were significantly inhibited. The maximum phenol removal rate observed was 780 kg/ha.d, which is 7.7 times higher than the maximum value reported for attached-growth waste stabilisation ponds. All along the experiments, the enriched ponds showed removal rates 1.8–20.5 times higher than the values observed in control pond (not enriched). The results suggest that enrichment is an effective method to increase xenobiotic removal rates of stabilisation ponds.

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