Comparison of nitrogen elimination rates of different constructed wetland designs

2011 ◽  
Vol 64 (5) ◽  
pp. 1122-1129 ◽  
Author(s):  
Eriona Canga ◽  
Sara Dal Santo ◽  
Alexander Pressl ◽  
Maurizio Borin ◽  
Guenter Langergraber

In this paper the nitrogen elimination rates of different constructed wetland (CW) designs reported in literature are compared with those obtained for outdoor and indoor 2-stage vertical flow (VF) systems. The outdoor system is located about 150 km west of Vienna. Both stages are planted with Phragmites australis and the system has been operated for 4 years continuously. During this period the average value of the nitrogen elimination rate was 3.30 g N m−2 d−1. The indoor system comprises three parallel operated 2-stage VF systems and is located in the technical lab hall at BOKU University. The design of the indoor system resembles the outdoor system. However, there are a few differences: (1) the indoor systems are not planted, and (2) different filter media have been used for the main layer of the first stages. With the indoor system the highest nitrogen elimination rate achieved was 2.24 g N m−2 d−1 for the system with zeolite and impounded drainage layer. Similar results have been found in France for treating raw wastewater with VF and horizontal flow (HF) beds in series with nitrogen elimination rates of 1.89 and 2.82 g N m−2 d−1 for differently designed HF beds. The highest nitrogen elimination rates of 15.9 g N m−2 d−1 reported were for pilot-scale VF CWs treating high-strength synthetic wastewater (total nitrogen of 305 mg L−1 in the influent) in Thailand. It has been shown that the outdoor two-stage VF CW system has one of the highest nitrogen elimination rates of CWs treating domestic wastewater.

2011 ◽  
Vol 64 (5) ◽  
pp. 1137-1141 ◽  
Author(s):  
Guenter Langergraber ◽  
Alexander Pressl ◽  
Klaus Leroch ◽  
Roland Rohrhofer ◽  
Raimund Haberl

In the first two years of operation a nitrogen removal efficiency of 53% and a high average elimination rate of 1,000 g N m−2 yr−1 could be observed for a two-stage vertical flow (VF) constructed wetland (CW) system. The two-stage system consists of two VF beds with intermittent loading operated in series, each stage having a surface area of 10 m2. The first stage uses sand with a grain size of 2–3.2 mm for the 50 cm main layer and has a drainage layer that is impounded; the second stage sand with a grain size of 0.06–4 mm and a conventional drainage layer (with free drainage). The two-stage VF system was designed for and operated with an organic load of 40 g COD m−2 d−1 (i.e. 2 m2 per person equivalent). Data from the following years of operation showed that from the third year nitrogen elimination increased and stabilized. The median values of the nitrogen elimination rate in the first five years of operation have been 3.51, 2.76, 4.20, 3.84 and 4.07 g N m−2 d−1, the median value of the last three years being 3.8 g N m−2 d−1 and 1,380 g N m−2 yr−1, respectively, and the nitrogen removal >60%. It can be assumed that the vegetation as well as the biofilm development in the two-stage VF CW system plays the major role for the enhancement of the nitrogen elimination rate.


2005 ◽  
Vol 51 (10) ◽  
pp. 327-334 ◽  
Author(s):  
A. Bick ◽  
J.G.P. Tuttle ◽  
S. Shandalov ◽  
G. Oron

In many regions dairy farms and milk processing industries discharge large quantities of their wastes to the surroundings posing serious environmental risks. This problem is mostly faced in small dairy farms and isolated communities lacking both central collection and conventional wastewater treatment systems. Dairy wastewater is characterized by high concentrations of organic matter, solids, nutrients, as well as fractions of dissolved inorganic pollutants, exceeding those levels considered typical for high strength domestic wastewaters. With the purpose of treating the combined dairy and domestic wastewater from a small dairy farm in the Negev Desert of Israel, the use of a recent emerging technology of Immersed Membrane BioReactor (IMBR) was evaluated over the course of 500 test hours, under a variety of wastewater feed quality conditions (during the test periods, the feed BOD5 ranged from 315 ppm up to 4,170 ppm). The overall performance of a pilot-scale Ultrafiltration (UF) IMBR process for a combined domestic and dairy wastewater was analyzed based on the Data Envelopment Analysis (DEA) method. The IMBR performance in terms of membrane performance (permeate flux, transmembrane pressure, and organic removal) and DEA model (Technical Efficiency) was acceptable. DEA is an empirically based methodology and the research approach has been found to be effective in the depiction and analysis for complex systems, where a large number of mutual interacting variables are involved.


2021 ◽  
Vol 319 ◽  
pp. 01065
Author(s):  
Aziz Taouraout ◽  
Abdelkader Chahlaoui ◽  
Khadija Ouarrak ◽  
Hicham Aaziz ◽  
Driss Belghyti

Wastewater and human excreta are threatening the quality of groundwater and watercourses in rural areas of Morocco. The new sanitation approach that has advantage to solve the problems of pathogens of human waste at source and offering the possibility of reusing them after treatment is called Ecological Sanitation (EcoSan) could be an alternative solution to the conventional one. It is in this perspective that our study made an investigation on economic, ecological, sustainable sanitation techniques adapted to the Moroccan context. Indeed, a survey was carried out at Dayet Ifrah village to assess the population appreciation of the EcoSan structures installed. Survey results showed that these structures have been generally accepted by almost all users and non-users (95%). On the other hand, a pilot-scale system composed by two types of filters (vertical constructed wetland and vertical Multi-Soil-Layering) have been installed in order to treat domestic wastewater coming from a single household and their performance was evaluated. The filters showed good performance to remove organic pollution (> 84.5%) and orthophosphate (> 68%). The reduction of ammonium were 84.5% and 35.3% for vertical Multi-Soil-Layering and vertical constructed wetland, respectively. The quality of the wastewater treated was evaluated in accordance with the standard of the rejection limit value adopted by Morocco.


2011 ◽  
Vol 6 (3) ◽  
Author(s):  
P. K. Sharma ◽  
T. Inoue ◽  
K. Kato ◽  
H. Ietsugu ◽  
K. Tomita ◽  
...  

A real scale hybrid constructed wetland (CW) system (656 m2), with a configuration of VFA-VFB-HF beds constructed in series is operating since November 2006 in northern Hokkaido, Japan. The system was experimented to assess its capability in purifying 4.5 m3d−1 of high strength milking parlor wastewater under colder climate. Annual mean air temperature at site was recorded as 6.4 oC (extremes vary as -22.8 oC at lowest and 30.6 oC at highest). From the monthly sampling from November 2006 to January 2010, average loading and removal rates of TSS, CODcr, BOD5, TN and TP were 5.4 g m−2 d−1 (98%), 30.3 g m−2 d−1 (88%), 11.5 g m 2 d−1 (89%), 1.2 g m−2 d−1 (76.4%) and 0.2 g m−2 d−1 (76%). System did not stop for a single day, efficiently worked even during snow covered periods and was tolerant to the load fluctuations.


2007 ◽  
pp. 419-428
Author(s):  
R.M. Al-Sa 'ed ◽  
N. Mahmoud ◽  
A. Abu-Madi ◽  
O.R. Zimmo

This paper evaluates the feasibility of using local rock filter as natural media in waste stabilization ponds, A pilot-scale algae-rock filter ponds (ARPs) system was investigated, in parallel with algae-based ponds (ABPs) over a period of 6 months to evaluate the treatment efficacy of both systems. Each system entailed 4 equal ponds in series and was continuously fed with domestic wastewater from Birzeit University. The removal rates of organic matter, nutrients and faecal coliforms were monitored within each treatment system. The results obtained revealed that ARPs system was more efficient in the removal of organic matter (TSS and COD; 86% and 84%, respectively) and fecal coliforms (4 log10) than ABPs (81%, 81%, 3 log10, respectively). Nitrogen was reduced in the ARPs to an average of24 mg N/1; in contrast the ABPs effluent contained 32 mg N/1. Compared to ABP system, passive aerated ARPs option is an efficient, a low-cost and land-saving alternative with effluent quality suitable for restricted agricultural use in rural areas.


2018 ◽  
Vol 56 (4) ◽  
pp. 482 ◽  
Author(s):  
Hiep Trung Nguyen ◽  
Hong Tuyet Thi Le ◽  
Nga Thi Dinh ◽  
Tuan Dinh Phan

The aim of this study was to evaluate the performance of a down-flow hanging sponge (DHS) system in treating domestic wastewater. A pilot-scale of DHS system with a capacity of 60 L was designed and fabricated from polyvinyl chloride (PVC). The dimensions of DHS system are 1.5 m in height and square surface with 0.2 m in width, consists of three identical segments connected vertically in series. Each segment was filled by polyurethane sphere containing sponge. The total area of sponge and polyurethane sphere was 3,300 m2 m-3, density at 150 kg m-3, void ratio at 90%. DHS system was operated at ambient temperature within 82 days and stepwise increased of organic f rate from 0.5 to 1 and 1.5 kg COD m-3 d-1. The results showed that, this system performed well throughout the operational period and achieve the maximum removal of COD, BOD5, NH4+-N, and TN as 80%, 83%, 65% and 60%. The effluent of wastewater from DHS system achieved the requirement for National technical regulation on domestic wastewater of Vietnam type B QCVN 14:2008/BTNMT. In conclusion, the performance of DHS system indicated a high potential for application in removing organic matter and converting nitrogen ammonia to nitrogen nitrate, however it did not perform well for the removal of total nitrogen, it is necessary to study further by providing an anoxic zone in the system to enhance the treatment of nutrient in wastewater.


1992 ◽  
Vol 26 (9-11) ◽  
pp. 2225-2228 ◽  
Author(s):  
F. Çeçen ◽  
I. E. Gönenç

Design criteria for nitrification and denitrification of high-strength nitrogenous wastes have been derived by pilot-scale experiments in two submerged filters in series. Molasses proved to be a suitable carbon source in denitrif ication. It has been shown that oxygen is the rate limiting substrate in nitrification and that maximum denitrification rates can only be achieved at an influent COD/NOX−N ratio of approximately 5.


2013 ◽  
Vol 448-453 ◽  
pp. 604-607 ◽  
Author(s):  
Hong Jie Sun ◽  
Xin Nan Deng ◽  
Rui Chen

Research was conducted on pilot-scale, two-stage batch-flow constructed wetland systems for domestic wastewater treatment. Synthetic domestic wastewater was treated in a pre-acidification reactor with a hydraulic retention time (HRT) of 3 hours and the average removal rate of chemical oxygen demand (COD) and ammonia-nitrogen (NH4-N) reached 30% and 13.6%, respectively. The first-stage constructed wetland operated with up-flow and batch feed and drain. One cycle was 12h, including 6h feed and 6h drain. With HRT of 3 days, the effluent COD concentrations fluctuated from 32.5 mg/L to 103.4 mg/L, removal rates varied from 60% to 88%; effluent NH4-N concentrations were in the range of 4.8 mg/L to 10.8 mg/L, removal rates varied from 50% to 70%. The second-stage constructed wetland operated with down-flow, which one cycle was 24h, including 12h feed and 12h drain. With HRT of 1 day, effluent COD concentrations varied from 15.7 mg/L to 48.7 mg/L, removal averaged 53.2%; effluent NH4-N concentrations ranged from 0 mg/L to 0.4 mg/L, average removal exceeded 99%. The spatial variation of COD and NH4-N in the first-stage constructed wetland demonstrated that entrainment of air during draining of constructed wetland could strengthen the removal of COD and NH4-N. Temperature had no significant effect on COD degradation while obviously affected the removal of NH4-N.


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