Evaluation of extremely shallow vertical subsurface flow constructed wetland for nutrient removal

2009 ◽  
Vol 59 (2) ◽  
pp. 295-301 ◽  
Author(s):  
T. Taniguchi ◽  
K. Nakano ◽  
N. Chiba ◽  
M. Nomura ◽  
O. Nishimura
Keyword(s):  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Nutrient Removal ◽  
Phosphorus Removal ◽  
Sewage Treatment ◽  
Subsurface Flow ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Basic Nitrogen ◽  
Reed Bed

Mesocosm-scale vertical subsurface flow constructed wetlands (SSF, 0.5 m length, 0.3 m width) with different reed-bed thickness, including standard SSF (SD, 0.6 m deep), shallow SSF (S, 0.3 m deep) and extremely shallow SSF (ES, 0.075 m deep) were set up at sewage treatment plant and their nutrient removal efficiencies from the sewage plant effluent were compared under three hydraulic loading rate (HLR) conditions of 0.15, 0.45 and 0.75 m3 m−2 d−1. A very interesting characteristics was found for the extremely shallow SSF, in which a high nitrogen removal efficiency was obtained despite the effective hydraulic retention time was only 1/8 times as long as the standard SSF. The results of kinetic analysis confirmed that the high volumetric nitrogen removal efficiency observed in the extremely shallow SSF did not depend on high response against the water temperature but on much higher basic nitrogen removal activity compared with other SSF. The phosphorus removal depending on the adsorption to sand in the reed-bed filter was, however, the lowest in the extremely shallow SSF although the volumetric removal efficiency was much higher compared with other SSF. Results of morphological analysis of rhizosphere collected from respective reed-bed suggested that the extremely shallow SSF lead to a very high-density rhizosphere, resulting in a high basic nitrogen removal activity and volumetric phosphorus removal efficiency.

Possibilities for increased nutrient removal with a final filtration stage

1996 ◽  
Vol 33 (12) ◽  
pp. 147-153
Author(s):  
M. Rothman ◽  
J. Hultgren
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Nutrient Removal ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
High Concentrations ◽  
Winter Time ◽  
Filtration Stage

Bromma sewage treatment plant (STP) is one of three plants in Stockholm. To meet more stringent requirements for nutrient removal the plant has been extended with a final filtration stage. Earlier it has not been possible to operate the plant with nitrification during winter time. Bad settling properties of the activated sludge have led to bulking sludge and high concentrations of BOD and phosphorus in the effluent. With the filter stage it is now possible to reduce the load on the biological stage by by-passing part of the flow directly to the filters. The result has been very promising and it seems that the plant can meet the new demands for nitrogen removal without extension of the aerated volumes.

Impact of cold and dilute sewage on pre-fermentation - a case study

2001 ◽  
Vol 43 (11) ◽  
pp. 109-117 ◽  
Author(s):  
D. Bixio ◽  
P. van Hauwermeiren ◽  
C. Thoeye ◽  
P. Ockier
Keyword(s):  
Phosphorus Removal ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
High Rate ◽  
Cold Weather ◽  
Biological Nutrient Removal ◽  
Municipal Sewage ◽  
Biological Phosphorus Removal ◽  
Primary Sludge

The municipal sewage treatment plant (STP) of the city of Ghent (Belgium) has to be retrofitted to a 43%-increase in the nitrogen treatment capacity and to phosphorus removal. Cold weather, dilute sewage and a critical COD over N ratio make the retrofit a challenge for full biological nutrient removal. The potential for fermentation of primary sludge to alter those critical feed sewage characteristics was experimentally evaluated. The idea was that the pinpoint introduction of fermentate could optimise the available reactors by achieving high-rate denitrification and enhanced biological phosphorus removal. The fermentation process was evaluated with a bench scale apparatus. At 20°C (heated process), the hydrolysis yield - expressed in terms of soluble COD - varied from 11% to 24% of the total sludge COD. The fermentation yield expressed in VFA COD varied from 8% to 13% of the total sludge COD. The efficiency of heated fermentation of primary sludge was lower during cold and wet weather, due to the different sewage characteristics, as a result of extended dilution periods and low temperature. The raw sewage, the primary effluent and the fermentate were fractionated according to the requirements for the IAWQ Activated Sludge Model No. 2d. The results clearly show that fermentation in the sewer played an important role and temperature was the driving parameter for the characteristics of the dissolved COD. Instead, the weather flow conditions were the driving parameter for the characteristics of the suspended COD. The results of the detailed fractionation were used as background for process evaluation. The final scenario choice for the retrofit depends on a cost-efficiency calculation.

scholarly journals Performance of sewage treatment plant with septic tank, anaerobic filter and constructed wetland with Typha spp

2019 ◽  
Vol 14 (7) ◽  
pp. 1
Author(s):  
Paulo Fortes Neto ◽  
Nara Lucia Perondi Fortes ◽  
Elizabeth Da Costa Neves Fernandes de Almeida Duarte ◽  
Rita Do Amaral Fragoso ◽  
Ana Catarina Marcos Henriques ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Constructed Wetland ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Climatic Conditions ◽  
Effluent Treatment ◽  
Septic Tank ◽  
Anaerobic Filter ◽  
Before And After

  The study reports the performance of a sanitary effluent treatment constituted by a septic tank, anaerobic filter and constructed wetland. The study monitored nutrient’s, carbonaceous material’s and thermotolerant coliform’s (CT) removal efficiency during 12 months. The treatment system included a septic tank, an anaerobic filter and a horizontal subsurface flow constructed wetland cultivated with Typha spp. Effluent samples were monthly collected before and after the septic tank, anaerobic filter and wetland. The removal efficiency for N-NH+4 was 37.6%, 66.3% for total P, 37% for COD, 54% for BOD and 99.4% for CT. The anaerobic filter and wetland were more efficient than the septic tank. P-total reduction was higher in the constructed wetland than in the anaerobic filter. Climatic conditions influenced the evaluated constituent’s removal being the highest values during hot months.

Enhanced nitrogen removal in trickling filter plants

2013 ◽  
Vol 67 (10) ◽  
pp. 2273-2280 ◽  
Author(s):  
Y. Dai ◽  
A. Constantinou ◽  
P. Griffiths
Keyword(s):  
Rural Communities ◽  
Nitrogen Removal ◽  
Pilot Trial ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Ammonium Concentration ◽  
Trickling Filter ◽  
Solids Retention ◽  
Plant Trial

The Beaudesert Sewage Treatment Plant (STP), originally built in 1966 and augmented in 1977, is a typical biological trickling filter (TF) STP comprising primary sedimentation tanks (PSTs), TFs and humus tanks. The plant, despite not originally being designed for nitrogen removal, has been consistently achieving over 60% total nitrogen reduction and low effluent ammonium concentration of less than 5 mg NH3-N/L. Through the return of a NO3−-rich stream from the humus tanks to the PSTs and maintaining an adequate sludge age within the PSTs, the current plant is achieving a substantial degree of denitrification. Further enhanced denitrification has been achieved by raising the recycle flows and maintaining an adequate solids retention time (SRT) within the PSTs. This paper describes the approach to operating a TF plant to achieve a high degree of nitrification and denitrification. The effectiveness of this approach is demonstrated through the pilot plant trial. The results from the pilot trial demonstrate a significant improvement in nitrogen removal performance whilst maximising the asset life of the existing infrastructure. This shows great potential as a retrofit option for small and rural communities with pre-existing TFs that require improvements in terms of nitrogen removal.

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