Tertiary treatment in a vertical flow reed bed system – a full scale pilot plant for 200–600 P.E.

1997 ◽  
Vol 35 (5) ◽  
pp. 223-230 ◽  
Author(s):  
Monika Schönerklee ◽  
Ferdinand Koch ◽  
Reinhard Perfler ◽  
Raimund Haberl ◽  
Johannes Laber
Keyword(s):  
Pilot Plant ◽  
Oxygen Demand ◽  
Operational Reliability ◽  
Full Scale ◽  
Vertical Flow ◽  
Tertiary Treatment ◽  
N Removal ◽  
Hydraulic Load ◽  
Reed Bed ◽  
One Year

In Strengberg, Lower Austria, a vertical flow reed bed system (gravel/sand) was chosen as a new type of tertiary treatment which was designed as a full scale pilot plant with various possibilities of operational use. The surface of the vertical flow pilot plant amounts to about 600 m2 and is divided into four beds whereby two different depths of substrate are used. The application of the conventional plant effluent is carried out in intermittent flushes and at changeable time intervals. Final nitrification and partial denitrification and elimination of phosphorus are the main goals to be achieved. In the framework of the present research project the load limits will be determined by gradually raising the influent load. The efficiency and operational reliability within the whole year period (summer/winter) are considered to be an important factor for establishing general dimensioning approaches. The pilot plant has been in operation for more than one year now. Different operational stages up to a hydraulic load of 1.3 m2.p.e.−1 (i.e. 0.75 m2.p.e.−1) were carried out. The average chemical oxygen demand (COD) of the reed bed effluents varied from 1 to 20 mg.1−1. Not surprisingly the ammonium (NH4-N) results showed more variation. Results, thus far, indicate NH4-N removal efficiencies between 40% and 90%.

Experiences from the full-scale implementation of a new two-stage vertical flow constructed wetland design

2013 ◽  
Vol 69 (2) ◽  
pp. 335-342 ◽  
Author(s):  
Guenter Langergraber ◽  
Alexander Pressl ◽  
Raimund Haberl
Keyword(s):  
Constructed Wetland ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Full Scale ◽  
Vertical Flow ◽  
Effluent Water ◽  
Two Stage ◽  
Vertical Flow Constructed Wetland ◽  
Hydraulic Load ◽  
Public Holidays

This paper describes the results of the first full-scale implementation of a two-stage vertical flow constructed wetland (CW) system developed to increase nitrogen removal. The full-scale system was constructed for the Bärenkogelhaus, which is located in Styria at the top of a mountain, 1,168 m above sea level. The Bärenkogelhaus has a restaurant with 70 seats, 16 rooms for overnight guests and is a popular site for day visits, especially during weekends and public holidays. The CW treatment system was designed for a hydraulic load of 2,500 L.d−1 with a specific surface area requirement of 2.7 m2 per person equivalent (PE). It was built in fall 2009 and started operation in April 2010 when the restaurant was re-opened. Samples were taken between July 2010 and June 2013 and were analysed in the laboratory of the Institute of Sanitary Engineering at BOKU University using standard methods. During 2010 the restaurant at Bärenkogelhaus was open 5 days a week whereas from 2011 the Bärenkogelhaus was open only on demand for events. This resulted in decreased organic loads of the system in the later period. In general, the measured effluent concentrations were low and the removal efficiencies high. During the whole period the ammonia nitrogen effluent concentration was below 1 mg/L even at effluent water temperatures below 3 °C. Investigations during high-load periods, i.e. events like weddings and festivals at weekends, with more than 100 visitors, showed a very robust treatment performance of the two-stage CW system. Effluent concentrations of chemical oxygen demand and NH4-N were not affected by these events with high hydraulic loads.

Septage dewatering in vertical-flow constructed wetlands located in the tropics

2001 ◽  
Vol 44 (2-3) ◽  
pp. 181-188 ◽  
Author(s):  
T. Koottatep ◽  
C. Polprasert ◽  
N. T.K. Oanh ◽  
U. Heinss ◽  
A. Montangero ◽  
...  
Keyword(s):  
Constructed Wetlands ◽  
Low Cost ◽  
Drainage System ◽  
Oxygen Demand ◽  
Free Water ◽  
Total Solid ◽  
Solid Loading ◽  
Flow Mode ◽  
Vertical Flow ◽  
N Removal

Constructed wetlands (CWs) have been proven to be an effective low-cost treatment system, which utilizes the interactions of emergent plants and microorganisms in the removal of pollutants. CWs for wastewater treatment are normally designed and operated in horizontal-flow patterns, namely, free-water surface or subsurface flow, while a vertical-flow operation is normally used to treat sludge or septage having high solid contents. In this study, three pilot-scale CW beds, each with a surface area of 25 m2, having 65 cm sand-gravel substrata, supported by ventilated-drainage system and planting with narrow-leave cattails (Typha augustifolia), were fed with septage collected from Bangkok city, Thailand. To operate in a vertical-flow mode, the septage was uniformly distributed on the surface of the CW units. During the first year of operation, the CWs were operated at the solid loading rates (SLR) and application frequencies of, respectively, 80-500 kg total solid (TS)/m2.yr and 1-2 times weekly. It was found that the SLR of 250 kg TS/m2.yr resulted in the highest TS, total chemical oxygen demand (TCOD) and total Kjeldahl nitrogen (TKN) removal of 80, 96 and 92%, respectively. The TS contents of the dewatered septage on the CW beds were increased from 1-2% to 30-60% within an operation cycle. Because of the vertical-flow mode of operation and with the effectiveness of the ventilation pipes, there were high degrees of nitrification occurring in the CW beds. The nitrate (NO3) contents in the CW percolate were 180-250 mg/L, while the raw septage had NO3 contents less than 10 mg/L. Due to rapid flow-through of the percolates, there was little liquid retained in the CW beds, causing the cattail plants to wilt, especially during the dry season. To reduce the wilting effects, the operating strategies in the second year were modified by ponding the percolate in the CW beds for periods of 2 and 6 days prior to discharge. This operating strategy was found beneficial not only for mitigating plant wilting, but also for increasing N removal through enhanced denitrification activities in the CW beds. During these 2 year operations, the dewatered septage was not removed from the CW beds and no adverse effects on the septage dewatering efficiency were observed.

Compact vertical flow constructed wetland systems - first two years’ performance

2003 ◽  
Vol 48 (5) ◽  
pp. 15-23 ◽  
Author(s):  
C.M. Weedon
Keyword(s):  
Oxygen Transfer ◽  
Transfer Rate ◽  
Oxygen Transfer Rate ◽  
Oxygen Demand ◽  
Phosphate Removal ◽  
Normal Operation ◽  
Vertical Flow ◽  
Average Percentage ◽  
Load Rate ◽  
Reed Bed

In order to move towards optimising wastewater treatment performance by vertical down-flow reed beds, user and installer demands were applied to design, resulting in the “compact vertical flow reed bed” (CVF bed). Performance data are presented for the two years since commissioning a CVF bed and pond system serving eight residents. Particular emphasis was placed on investigating oxygen transfer rate and susceptibility to hydraulic overloading. Average percentage concentration reduction effected by single passage through the bed exceeded 97% for suspended solids and biochemical oxygen demand, and 90% for ammoniacal nitrogen and total Kjeldahl nitrogen. The occurrence of nitrification and denitrification (up to 58%) within the same bed was clearly indicated. Percentage ortho-phosphate removal averaged 92% over the first 17 months’ operation and thereafter fell to approximately 45%. Faecal coliform density underwent an almost four log reduction. Oxygen transfer rate within the reed bed was between 28-36 gO2/m2.d. Normal operation was maintained until six times dry weather hydraulic load rate was exceeded, at which point surface flooding occurred. The capacity of a single vertical flow reed bed to achieve effective treatment of domestic sewage was demonstrated, with no requirement for reduced load rates, promising substantial advantages over established approaches.

scholarly journals Performance of a French system of vertical flow wetlands (first stage) operating with an extended feeding cycle

2019 ◽  
Vol 80 (8) ◽  
pp. 1443-1455 ◽  
Author(s):  
Camila Maria Trein ◽  
Jorge Alejandro García Zumalacarregui ◽  
Mirene Augusta de Andrade Moraes ◽  
Marcos von Sperling
Keyword(s):  
Oxygen Demand ◽  
Climatic Conditions ◽  
Nitrification Rate ◽  
Vertical Flow ◽  
Intensive Monitoring ◽  
The Third ◽  
Treatment Performance ◽  
N Removal ◽  
Feeding Cycle ◽  
Deposit Layer

Abstract The aim of this work was to evaluate the treatment performance in the first stage of a vertical flow constructed wetland – French system (VCW-FS) over an extended feeding period (seven days), in two parallel units, for a population equivalent (p.e.) around 100 inhabitants (total of 0.6 m²·p.e.−1), under Brazilian tropical climatic conditions. One of the units had a greater surface sludge deposit layer, accumulated over nine years of operation, while the other unit had its sludge removed prior to the experiments. Four intensive monitoring campaigns covering all days of the feeding cycle were undertaken and the results were compared with those obtained from the conventional monitoring. The results indicated that, over the days of the feeding cycle, dissolved oxygen concentrations decreased, but were still kept at sufficiently high values for the removal of organic matter. Therefore, chemical oxygen demand (COD) removal, although not high, remained acceptable for compliance with local discharge standards during the whole the period. The NH4+-N removal efficiency and NO3−-N production were higher at the beginning of the feeding cycle, as a result of the more well-established aerobic conditions, with the nitrification rate decreasing from the third day of feeding. The sludge deposit seemed to hinder liquid percolation, especially at the end of the feeding cycle, thus affecting oxygen transfer. Due to the variability of the results over the feeding cycle, if sampling is to be done once a week, it is important to identify the sampling day that best represents the system's performance.

Effects of a saturated layer and recirculation on nitrogen treatment performances of a single stage Vertical Flow Constructed Wetland (VFCW)

2013 ◽  
Vol 68 (7) ◽  
pp. 1461-1467 ◽  
Author(s):  
S. Prigent ◽  
J. Paing ◽  
Y. Andres ◽  
F. Chazarenc
Keyword(s):  
Constructed Wetland ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Single Stage ◽  
Vertical Flow ◽  
Saturated Layer ◽  
Vertical Flow Constructed Wetland ◽  
Hydraulic Load ◽  
Nitrogen Concentrations ◽  
Kjeldahl Nitrogen

Upgrades to enhance nitrogen removal were tested in a 2 year old pilot vertical flow constructed wetland in spring and summer periods. The effects of a saturated layer and of recirculation were tested in particular. Two pilots (L = 2 m, W = 1.25 m, H = 1.2 m), filled with expanded schist (Mayennite®), were designed with hydraulic saturated layers of 20 and 40 cm at the bottom. Each pilot was fed with raw domestic wastewater under field conditions according to a hydraulic load of 15–38 cm d−1 (i.e. 158–401 g COD (chemical oxygen demand) m−2 d−1) and to recirculation rates ranging from 0% up to 150%. The initial load during the first 2 years of operation resulted in an incomplete mineralized accumulated sludge leading to total suspended solids (TSS), COD and biochemical oxygen demand (BOD5) release. A 40 cm hydraulic saturated layer enabled an increase of 5–10% total nitrogen (TN) removal compared to a 20 cm saturated layer. Recirculation allowed the dilution of raw wastewater and enhanced nitrification in a single stage. A design of 1.8 m² pe−1 (48 cm d−1, 191 g COD m−2 d−1) with a 40 cm saturated layer and 100% recirculation enabled the French standard D4 (35 mg TSS L−1, 125 mg COD L−1, 25 mg BOD5 L−1), nitrogen concentrations below 20 mg TKN (total Kjeldahl nitrogen) L−1 and 50 mg TN L−1, to be met.

Dewatering and Mineralization of Sludge from Secondary Sedimentation Tank in a Constructed Sludge Drying Reed Bed

2012 ◽  
Vol 209-211 ◽  
pp. 1111-1115
Author(s):  
Chun Zhang ◽  
Jie Deng ◽  
Wei Zhang
Keyword(s):  
Heavy Metals ◽  
Removal Rate ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Bottom Layer ◽  
Heavy Metal Concentration ◽  
The European Union ◽  
Sedimentation Tank ◽  
Reed Bed ◽  
One Year

The dewatering and mineralization of sludge in the constructed reed bed was investigated in this study.The sludge from the secondary sedimentation tank is from in the wastewater treatment plant in Yiyang city,Hunan province.Anaerobic pond and oxidation ditch biological treatment processes is accepted there.The performance of the system was monitored for one year. Total Solids (TS), Volatile Solids(VS), Chemical Oxygen Demand, nutrients (TKN) and Total Phosphorus(TP), heavy metals in the sludge were analysed.The removal rate of COD,NH4-N,and TP of the percolated fluid for the first cycle was also monitored. TS content reached 36.5% for the surface layer and 37.8% for the bottom layer at the end of the examination period.Sludge stabilization in the bed was also observed(VS content decreased to 31.3% and 13.4% respectively for the surface and bottom layer).Concentration of nutrients of the sludge accumulated in the bed also decreased. The heavy metal concentration meets the European Union standards for heavy metals in case of agricultural disposal of the treated sludge.

Treatment of high organic content wastewater from food-processing industry with the French vertical flow constructed wetland system

2015 ◽  
Vol 72 (1) ◽  
pp. 70-76 ◽  
Author(s):  
J. Paing ◽  
V. Serdobbel ◽  
M. Welschbillig ◽  
M. Calvez ◽  
V. Gagnon ◽  
...  
Keyword(s):  
Food Processing ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Full Scale ◽  
Organic Load ◽  
Organic Loading Rate ◽  
Vertical Flow ◽  
Food Processing Industry ◽  
Processing Industry ◽  
The Mean

Abstract This study aimed at determining the treatment performances of a full-scale vertical flow constructed wetlands designed to treat wastewater from a food-processing industry (cookie factory), and to study the influence of the organic loading rate. The full-scale treatment plant was designed with a first vertical stage of 630 m², a second vertical stage of 473 m² equipped with a recirculation system and followed by a final horizontal stage of 440 m². The plant was commissioned in 2011, and was operated at different loading rates during 16 months for the purpose of this study. Treatment performances were determined by 24 hour composite samples. The mean concentration of the raw effluent was 8,548 mg.L−1 chemical oxygen demand (COD), 4,334 mg.L−1 biochemical oxygen demand (BOD5), and 2,069 mg.L−1 suspended solids (SS). Despite low nutrients content with a BOD5/N/P ratio of 100/1.8/0.5, lower than optimum for biological degradation (known as 100/5/1), mean removal performances were very high with 98% for COD, 99% for BOD5 and SS for the two vertical stages. The increasing of the organic load from 50 g.m−2.d−1 COD to 237 g.m−2.d−1 COD (on the first stage) did not affect removal performances. The mean quality of effluent reached French standards (COD < 125 mg.L−1, BOD5 < 25 mg.L−1, SS < 35 mg.L−1).

scholarly journals Effectiveness of septage pre-treatment in vertical flow constructed wetlands

2017 ◽  
Vol 76 (9) ◽  
pp. 2544-2553 ◽  
Author(s):  
Beata Karolinczak ◽  
Wojciech Dąbrowski
Keyword(s):  
Constructed Wetlands ◽  
Municipal Wastewater ◽  
Oxygen Demand ◽  
Vegetation Period ◽  
Ammonia Nitrogen ◽  
Vertical Flow ◽  
Municipal Wastewater Treatment ◽  
Vertical Flow Constructed Wetlands ◽  
Hydraulic Load ◽  
Pre Treatment

Abstract Septage is wastewater stored temporarily in cesspools. A periodic supply of its significant quantities to small municipal wastewater treatment plants (WWTPs) may cause many operational problems. In the frame of the research, it has been proposed to utilize vertical flow constructed wetlands for pre-treatment of septage prior to its input to the biological stage of a WWTP. The aim of the work was to assess the effectiveness of pre-treatment in relation to factors such as: seasonality, hydraulic load, pollutants load of the VF bed and interactions between these factors. The results proved that application of a VF bed to septage pre-treatment can significantly reduce the concentration of pollutants (biochemical oxygen demand (BOD5): 82%, chemical oxygen demand (COD): 82%, total suspended solids (TSS): 91%, total nitrogen (TN): 47%, ammonia nitrogen (NH4-N): 70%), and thus decrease the loading of the biological stage of a WWTP. The mathematical models of mass removal process were created. They indicate that in case of all analysed parameters, removed load goes up with the increase of load in the influent. However, with the increase of hydraulic load, a decrease of the removed BOD5, COD, TSS and total phosphorus, and in vegetation period an increase of TN, can be observed in terms of load. There are no statistically significant effects of seasonality.

scholarly journals Coupling of Reed Bed Filters and Ponds: An Example in France

1993 ◽  
Vol 28 (10) ◽  
pp. 159-167 ◽  
Author(s):  
A. Liénard ◽  
C. Boutin ◽  
R. Bois
Keyword(s):  
Residence Time ◽  
Removal Rate ◽  
Tertiary Treatment ◽  
Nitrogen And Phosphorus ◽  
Effective Surface ◽  
Treatment Stage ◽  
Usual Residence ◽  
Hydraulic Load ◽  
Reed Bed ◽  
Raw Wastewater

The study of wastewater treatment series based on the use of macrophyte beds, in accordance with a design initially developed in Germany by Dr. Seidel, was initiated by CEMAGREF in 1983. The number of plants constructed was deliberately limited and they were subject to regular assessments and improvements. It was thus shown that only reed bed filters that were drained and alternately fed, were able to handle a pollutant load of the order of 80 g COD m-2 day-1 with satisfactory treatment reliability over a period of several years. The Gensac la Pallue plant, in the Charente department, is original since it combines this type of filter in the first treatment stage with three microphyte ponds designed with a low theoretical residence time of 21 days (compared with the usual residence time of 30 days in tertiary treatment). The whole treatment series only occupies an effective surface area of approximately 6 m2 per p.e. (about 1 m2 and 5 m2 for filters and ponds respectively). After 5 years of operation and monitoring, it has been clearly established that filters dosed with raw wastewater at a rate of 65 g of COD and 30g of TSSm-3 per day, regularly achieve a removal rate of 70 to 85 % of these same elements without clogging. The daily hydraulic load that the filter can withstand in service regularly exceeded 2 metres in the month of November 1992. The ponds finish the treatment and this article limits itself to analysing results relating to the elimination of nutrient, which reaches 35% for nitrogen and 55% for phosphorus. Residence times that are too short in winter, in conjunction with a large part of the sewerage system being of combined type, can sometimes temporarily lead to an increase in the amounts of nitrogen and phosphorus discharged to the natural environment.

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