Constructed wetlands for wastewater treatment in Estonia

1997 ◽  
Vol 35 (5) ◽  
pp. 323-330 ◽  
Author(s):  
Ülo Mander ◽  
Tõnu Mauring
Keyword(s):  
Organic Matter ◽  
Constructed Wetlands ◽  
Overland Flow ◽  
Aquatic Macrophyte ◽  
Root Zone ◽  
Vertical Flow ◽  
Average Output ◽  
Total N ◽  
Input Load ◽  
Total P

In Estonia many natural/semi-natural wetlands have been used for municipal or agricultural wastewater. During the last 6 years twelve constructed wetlands for wastewater purification were established. Budgets of organic matter (BOD), total-N and total-P of three systems (a sand/plant filter with vertical flow, established in 1992, area 90 m2, loading 3.8 g BOD m−2 d−1; a combined overland flow-vertical flow root-zone system on a Phalaris arundinacea-slope, 1989, 2400 m2 ha, 1 g BOD m−2 d−1; an aquatic macrophyte channel (bioditch), 140 m2, 40 g BOD m−2 d−1), located in southern Estonia, are analyzed. Except for nitrogen, the efficiency of the sand/plant filter was found satisfactory: 82%, 36%, and 74% for BOD5, total-N, and total-P, respectively. The poor performance with respect to nitrogen may be caused by weak vegetation. In thePhalaris -system, 65% of organic matter, 67% N, and 80% P was removed. The average output concentrations of this system were always lower than the recommended limits (BOD5 <10 mg l−1, total-N <10 mg l−1, and total-P <2 mg l−1). Due to the high input load, the BOD5, total-N, and total-P values in the outlet of the bioditch were high and extremely variable: 5–100, 6–16, and 1–4 mg l−1, respectively. To guarantee the recommendable output values from the bioditch, either a significant decrease of input load or an enlargement of the area of the wetlands would be needed. All results show that compared to other seasons the winter performance was not reduced.

Experiences with a top layer of gravel to enhance the performance of vertical flow constructed wetlands at cold temperatures

2009 ◽  
Vol 59 (6) ◽  
pp. 1111-1116 ◽  
Author(s):  
Guenter Langergraber ◽  
Alexander Pressl ◽  
Klaus Leroch ◽  
Roland Rohrhofer ◽  
Raimund Haberl
Keyword(s):  
Organic Matter ◽  
Constructed Wetlands ◽  
Common Reed ◽  
Treated Wastewater ◽  
Second Phase ◽  
Vertical Flow ◽  
Cold Temperatures ◽  
Main Layer ◽  
Gravel Layer ◽  
Filter Bed

In a first phase of this study it was shown that the Austrian effluent standards for organic matter could not be met in winter for vertical flow (VF) beds designed for and loaded with 27 g COD.m−2.d−1 (3 m2 per person equivalent). The aim of this second phase of the study was to investigate, if the performance of a constructed wetland can be enhanced, i.e. if the effluent requirements can be met, when an additional gravel layer (15 cm, 4–8 mm) is added on top of the main layer of the VF bed. The hypothesis was that this top layer would increase the thermal insulation and consequently the temperatures in the filter bed during cold periods, thus resulting in higher removal efficiencies during winter. Two VF beds were operated in parallel; one bed with such a 15 cm top layer, one without. Otherwise the construction of both beds was identical: surface area of about 20 m2, 50 cm main layer (grain size 0.06–4 mm, d10=0.2 mm; d60=0.8 mm), planted with common reed (Phragmites australis). The beds were intermittently loaded 4 times per day with mechanically pre-treated wastewater (hydraulic loading: 47 mm.d−1; median value of the influent concentration: 505 mg COD.L−1). Despite a better performance during the first winter, the bed with additional top layer showed in general a very unstable performance. It is assumed that the main reason for this was that the oxygen transfer was reduced by the additional top layer so far that suspended organic matter could not any longer be degraded in between loadings. Therefore clogging of the filter occurred.

scholarly journals Simulating measurable ecosystem carbon and nitrogen dynamics with the mechanistically-defined MEMS 2.0 model

2021 ◽  
Author(s):  
Yao Zhang ◽  
Jocelyn M. Lavallee ◽  
Andy D. Robertson ◽  
Rebecca Even ◽  
Stephen M. Ogle ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Water ◽  
Root Zone ◽  
Ecosystem Respiration ◽  
Gross Primary Production ◽  
Total N ◽  
Calibration And Validation ◽  
Biogeochemical Models ◽  
Lower Accuracy ◽  
C Stocks

Abstract. For decades, predominant soil biogeochemical models have used conceptual soil organic matter (SOM) pools and only simulated them to a shallow depth in soil. Efforts to overcome these limitations have prompted the development of new generation SOM models, including MEMS 1.0, which represents measurable biophysical SOM fractions, over the entire root zone, and embodies recent understanding of the processes that govern SOM dynamics. Here we present the result of continued development of the MEMS model, version 2.0. MEMS 2.0 is a full ecosystem model with modules simulating plant growth with above and below-ground inputs, soil water, and temperature by layer, decomposition of plant inputs and SOM, and mineralization and immobilization of nitrogen (N). The model simulates two commonly measured SOM pools – particulate and mineral-associated organic matter (POM and MAOM), respectively. We present results of calibration and validation of the model with several grassland sites in the U.S. MEMS 2.0 generally captured the soil carbon (C) stocks (R2 of 0.89 and 0.6 for calibration and validation, respectively) and their distributions between POM and MAOM throughout the entire soil profile. The simulated soil N matches measurements but with lower accuracy (R2 of 0.73 and 0.31 for calibration and validation of total N in SOM, respectively) than for soil C. Simulated soil water and temperature were compared with measurements and the accuracy is comparable to the other commonly used models. The seasonal variation in gross primary production (GPP; R2 = 0.83), ecosystem respiration (ER; R2 = 0.89), net ecosystem exchange (NEE; R2 = 0.67), and evapotranspiration (ET; R2 = 0.71) were well captured by the model. We will further develop the model to represent forest and agricultural systems and improve it to incorporate new understanding of SOM decomposition.

scholarly journals Vertical flow constructed wetlands subject to load variations: an improved design methodology connected to outlet quality objectives

2015 ◽  
Vol 72 (5) ◽  
pp. 817-823 ◽  
Author(s):  
C. Boutin ◽  
S. Prost-Boucle
Keyword(s):  
Organic Matter ◽  
Constructed Wetlands ◽  
Oxygen Demand ◽  
Nitrification Rate ◽  
Vertical Flow ◽  
Design Standards ◽  
Rural Villages ◽  
Vertical Flow Constructed Wetlands ◽  
Nitrogen Concentrations ◽  
Improved Design

This study surveyed four campsites and four rural villages of major tourist interest, called tourist-interest or ti-villages, that were monitored for several years, generating over 70 performance balances for vertical flow constructed wetlands (VFCWs) that were intentionally scaled down for experimental trials. The wastewater effectively qualifies as domestic sewage, although relatively concentrated, with the campsites presenting particularly high nitrogen concentrations (122 gTKN L–1) (TKN: total Kjeldahl nitrogen). The applied daily loads were also particularly high, with some combinations of load parameters (hydraulic load, organic matter, TKN) leading to 400% overloading. Even under those drastic conditions, the quality of effluent remained excellent on the characteristic organic matter parameters, with removal performances always over 85%. Analysis of the dataset points to two major design thresholds: for campsites, in order to maintain a 73% nitrification rate even at the height of the summer season, the load applied onto the first stage filter in operation could achieve up to 600 gCOD m–2 day–1 (COD: chemical oxygen demand). For tourist-interest villages, in order to maintain an 85% nitrification rate, the load applied onto the second stage filter in operation could achieve up to 22 gTKN m–2.day–1. Here, VFCWs were demonstrated to robustly handle a massive increase in loads applied, providing the construction and operation stringently follow design standards and practices.

Constructed wetlands for the treatment of raw wastewater: the French experience

2014 ◽  
Vol 9 (3) ◽  
pp. 430-439 ◽  
Author(s):  
S. Troesch ◽  
F. Salma ◽  
D. Esser
Keyword(s):  
Organic Matter ◽  
Constructed Wetlands ◽  
Suspended Solids ◽  
Oxygen Demand ◽  
Vertical Flow ◽  
Small Communities ◽  
Vertical Flow Constructed Wetlands ◽  
French Experience ◽  
Raw Wastewater

Vertical flow constructed wetlands for small communities (<5,000 population equivalent) have been successfully developed in France since the 1990s (currently about 3'000 plants are in operation). This paper summarizes the results and efficiencies of 70 plants designed and built by Epur Nature or SINT. The results show clearly that the design performs well for organic matter removal and nitrification and makes sludge management easy. Therefore if well designed, such systems can achieve an outlet quality of BOD5 < 20 mg/L, chemical oxygen demand <90 mg/L, suspended solids <30 mg/L and TKN < 15 mg/L. In addition, some new configurations involving a French vertical first stage fed with raw sewage, patented by Epur Nature, are presented as an aid to reduce the global footprint.

Effect of density of Tephrosia candida stands on soil characteristics

2016 ◽  
Author(s):  
Zhiyang Lie ◽  
Zhuomin Wang ◽  
Li Xue
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Ph Value ◽  
Soil Nutrient ◽  
Stand Density ◽  
Nutrient Content ◽  
Total N ◽  
One Year ◽  
Tephrosia Candida ◽  
Total P

With one-year-old Tephrosia candida trees as experimental material, influence of stand density on soil nutrient content and enzyme activity was studied. The results showed that density had little influenced on pH value in 2, 4 and 8 trees m2 stands. The contents of soil organic matter, effective nitrogen and effective phosphorus significantly increased in 2 trees m2 stands. The contents of soil organic matter and effective nitrogen significantly increased, whereas total N, total P, total K, effective N, effective P and effective K significantly decreased in 4 trees/m2 stand. Soil organic matter and nutrients except for total P significantly decreased in 8 trees m2 stand. Among the three density stands, the activities of urease, catalase and phosphatase were the lowest in 8 trees m2 stand.

scholarly journals Karakteristik habitat dan pola pertumbuhan kepiting kelapa (Birgus latro) di Pulau Ternate dan Kabupaten Halmahera Barat Provinsi Maluku Utara

DEPIK ◽  
2016 ◽  
Vol 5 (2) ◽  
Author(s):  
Rugaya H. Serosero ◽  
Suryani . ◽  
Rina .
Keyword(s):  
Organic Matter ◽  
Air Temperature ◽  
Organic Matter Content ◽  
Environmental Parameters ◽  
Matter Content ◽  
Growth Patterns ◽  
Habitat Characteristics ◽  
Total N ◽  
Substrate Texture ◽  
Total P

Abstrak. Penelitian ini bertujuan untuk mengetahui karakteristik habitat dan pola pertumbuhan kepiting kelapa (Birgus latro) di Takome Pulau Ternate dan Idamdehe Kecamatan Jailolo Propinsi Maluku Utara. Penelitian ini dilaksanakan pada bulan April-Juli 2014. Data yang dikumpulkan adalah tekstur substrat dengan metode pipet, penentuan kandungan nitrat danfosfat tanah dengan metode spektofotometer, pengukuran panjang + rostrum (cp+r) kepiting kelapa dan pola pertumbuhannya. Selain it juga diukur suhu udara, suhu lubang dan kelembaban udara. Hasil penelitian menunjukkan bahwa Idamdehe memiliki karakteristik pantai yang curam, bahkan di beberapa lokasi penangkapan sangat terjal, sedangkan  di lokasi Takome Pulau Ternate memiliki karakteristik pantai yang lebih landai. Tekstur substrat di lokasi Takome Pulau Ternate terdiri atas pasir (55,76 %), debu (18,4%) dan liat (25,84%) dan Stasiun Idamdehe memiliki tekstur pasir (49,17%), debu (25,61%) dan liat (25,22%)dankandungan bahan organik substrat (Total N) di Takome adalah 0,31% dan total P adalah 0,09% sedangkan di Idamdehe Total N adalah 0,19% dan Total P 0,02%. Suhu udara di lokasi Idamdehe berkisar 26-280C dan di Takome 27-280C. Kelembaban udara 73%-98% di Idamdehe dan 71%-90% di Takome. Parameter lingkungan berupa suhu udara, kelembaban udara, tekstur substrat dan kandungan bahan organik di kedua lokasi penelitian mendukung kehidupan kepiting kelapa di habitat alaminya. Pola pertumbuhan kepiting kelapa di kedua lokasi Idamdehe adalah allometrik negatif.Kata kunci: Karakteristik habitat, Idamdehe, Takome, Birgus latro, isometrik, allometrik negatifAbstract. This objectives of the present study were to evaluate the habitat characteristics and growth patterns of the coconut crabs in Takome and Idamdehe waters North Maluku Province. This study was conducted during April-July 2014. The collected data were the substrate texture, nitrate and phosphate contents of soil using spectrophotometric method, length + rostrum (cp+r) of coconut crabs and the growth patterns. In addition, the air temperature, hole temperature and humidity were also recorded during the study. The results showed that Idamdehe waters has precipitous coast, indeed very precipitous in several catching locations, while Takome waters in Ternate Island has sloping coast. The substrate texture of Takome waters in Ternate Island consisted of sands (55.76%), dusts (18.4%) and clays (25.84%), while Idamdehe waters has the substrate texture that consisted of sands (49.17%), dusts (25.61 %) and clays (25.22%). As for organic matter contents of the substrate, Takome waters has 0.31% in total N and 0.09% in total P, while Idamdehe waters has 0.19% in total N and 0.02 % in total P. The air temperature in Idamdehe waters ranged between 26-280C and in Takome waters ranged between 27-280C. Air humidity in Idamdehe waters was 73%-98% and in Takome waters was 71%-90%. The environmental parameters such as temperature, humidity, substrate texture and organic matter content in both locations are suitable for coconut crab growing. The growth pattern of coconut crabs in Idamdehe and Sulamadaha waters were allometric negative pattern.Keywords: Habitat characteristics, Idamdehe, Takome, Birgus latro, isometric, negative allometric.

Influence of pH on the formation of organic and mineral colloïds and the associated release of various elements from surface sludge deposits of vertical flow constructed wetlands.

2020 ◽  
Author(s):  
Camille Banc ◽  
Mathieu Gautier ◽  
Blanc Denise ◽  
Lupsea-Toader Maria ◽  
Marsac Rémi ◽  
...  
Keyword(s):  
Trace Elements ◽  
Organic Matter ◽  
Constructed Wetlands ◽  
Organic Molecules ◽  
Major And Trace Elements ◽  
Vertical Flow ◽  
Colloidal Transport ◽  
Vertical Flow Constructed Wetlands ◽  
Neutralizing Capacity ◽  
Colloidal Carrier

<p>In the treatment of raw domestic wastewaters in vertical flow constructed wetlands (VFCW), a sludge layer is formed at the surface of the first-stage filters by the retention of wastewater’s suspended solids. The deposits constituting this layer is now known to accumulate and degrade a large variety of contaminants during regular conditions of operation. The potential release of the contaminants from the sludge deposits under disturbed conditions or during off-site sludge reuse is therefore a major concern. This study investigated the influence of organic colloids on the mobilization of major and trace elements bound to VFCW surface sludge deposits.   </p><p>Although the role of organic and/or mineral colloidal carrier phases in the transport of elements in natural systems has been extensively studied, little is known in contrast on the production of colloidal carrier phases from anthropic materials and media such as the sludge deposits considered here.</p><p>The acid/base neutralizing capacity (environmental assessment procedure ANC/BNC) (CEN/TS 14429) was carried out to assess the release at different pHs. Samples of sludge deposits were contacted with solutions in a wide pH range and the suspensions filtered through 0.45 µm acetate cellulose filters were subsequently analyzed. In addition, the suspensions were also treated by ultrafiltration using successively membranes of decreasing pore size (30 kDa, 10 kDa and 3 kDa). The leached organic molecules were thereby divided into three groups: (i) large colloids (30 kDa-0.45 µm), (ii) small colloids (10 kDa-3 kDa) and (iii) truly dissolved fraction (< 3 kda). The permeates were analyzed for major and trace elements and organic particles. UV-vis spectra were also recorded to evaluate organic matter aromaticity.  </p><p>Results showed that the molecular weight of the organic matter released was pH-dependent. Under very acidic conditions, the release of dissolved and poorly aromatic organic matter was mostly observed. At natural pH, close to neutrality, the sludge deposits released mostly large organic colloids. At higher pHs, the release of larger organic colloids was observed associated with an increase in the aromaticity of organic molecules.</p><p>The major and trace mineral elements released were found in the different fractions analyzed, depending on  their affinity with the organic colloidal carrier phases described previously. A first group of elements (As, P, B, V, Na, K) were mostly found in solution, and therefore poorly affected by colloidal transport regardless of pH conditions.  A second group (Co, Cu, Ni, Cd, Zn) was found to be relatively uniformly distributed in the fractions associated with the large and small colloids as well as in the dissolved fraction. A third group (Cr, Ba, Mn, Ca, Li, Mg, Sr) was mostly associated to large organic and/or mineral colloids.  </p><p>The results obtained in this study are a contribution to a better description of colloidal production and the release of associated elements and contaminants from VFCW sludge deposits. This is a key issue in the assessment of environmental risks related to the operation of the treatment plants or the reuse of the sludge material.</p>

The Effects of N and P Addition on the Soil Properties of a Eucalyptus urophylla Stand

2014 ◽  
Vol 700 ◽  
pp. 314-322
Author(s):  
Qiu Jing Li ◽  
Li Xue ◽  
Hong Yue Chen
Keyword(s):  
Organic Matter ◽  
Soil Bacteria ◽  
Eucalyptus Urophylla ◽  
N Addition ◽  
N Content ◽  
Total N ◽  
Available N ◽  
Biochemical Indices ◽  
P Addition ◽  
Total P

The effects of N and P addition on soil organic matter and nutrients, microbe and enzyme were investigated in a Eucalyptus urophylla stand to provide basis for soil management. Contents of organic matter, available P of N, P and N + P addition was significantly greater than the control, total N content of N and N+P addition was significant greater than the control, contents of total P, total K and available K of P and N + P addition was significantly greater than the control, available N content of N addition was significantly greater than the control, whereas that of P addition was significantly smaller than the control. N addition significantly increased the soil actinomyces number and urease activity, but had no significant effect on the number of soil bacteria and fungus, activities of phosphatase and catalase. Number of soil bacteria, fungus and actinomyces, activities of urease, phosphatase and catalase significantly increased after P addition, and biochemical indices except for bacteria number significantly increased after N + P addition.

scholarly journals Seasonal changes of contamination removal in constructed wetlands systems

2019 ◽  
pp. 327-338
Author(s):  
Magdalena Gajewska ◽  
Piotr Kowalik ◽  
Hanna Obarska-Pempkowiak
Keyword(s):  
Organic Matter ◽  
Constructed Wetlands ◽  
Seasonal Changes ◽  
Biological Treatment ◽  
Mechanical Treatment ◽  
Organic Matter Decomposition ◽  
Horizontal Flow ◽  
Municipal Sewage ◽  
Vertical Flow ◽  
Measurement Period

The investigation was carried out at two different hybrid constructed wetlands, whichtreated municipal sewage after mechanical treatment from small villages in PomeranianRegion, In all facilities first step of biological treatment were horizontal flow beds, Themain difference concerns configuration of the facilities and sewage distributions systemsinto vertical flow beds, The measurement period was divided into vegetation (from Aprilto October) and outside vegetation seasons (from November to March) for all analysedfacilities.The results allowed for estimation of efficiency removal of different contaminations inboth measurements seasons. Comparison of the amount of sewage and loads ofcontamination inflowing and outflowing from the facilities are presented. Achievedresults make it possible to estimate the rate of organic matter decomposition and nitrogenremoval in vegetation and outside vegetation seasons.

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