Phosphate and ammonium removal by constructed wetlands with horizontal subsurface flow, using shale as a substrate

1997 ◽  
Vol 35 (5) ◽  
pp. 95-102 ◽  
Author(s):  
A. Drizo ◽  
C. A. Frost ◽  
K. A. Smith ◽  
J. Grace
Keyword(s):  
Phragmites Australis ◽  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Subsurface Flow ◽  
Ammonium Removal ◽  
Ammonium N ◽  
Horizontal Subsurface Flow ◽  
P Removal

The objective was to investigate the performance of constructed wetlands with horizontal subsurface flow, using shale as a substrate, in removal of phosphate (P) and ammonium (N) from sewage. Shale was selected on the basis of its physico-chemical properties and its potential for P removal, investigated in an earlier study. A laboratory-scale constructed wetland system (CWS) employing horizontal subsurface flow was set up in a greenhouse, with and without Phragmites australis (reeds), and its capacity for simultaneous phosphate and ammonium removal from a synthetic sewage was monitored over a period of ten months. Both the planted and unplanted systems showed an extremely high P removal of 98–100% over the whole period of investigation. Ammonium N was also completely removed in the planted tanks, whereas in the unplanted ones the rates of removal varied between 40 and 75%; removal of nitrate N varied between 85 and 95% in planted and between 45 and 75% in unplanted tanks. pH, Eh and temperature did not differ significantly among planted and unplanted tanks, but the inlet Eh was correlated with P removal (r2 = 0.73; p < 0.05). The presence of Phragmites australis contributed significantly (p < 0.05) to P and N removal. In addition the plants showed excellent growth (up to 2 m in the first year), with good root and rhizome development, and showed potential for heavy metal removal. It was concluded that the shale-based system (which uses a readily available material) shows promise as a substrate for constructed wetland systems.

scholarly journals Partition and Fate of Phthalate Acid Esters (PAEs) in a Full-Scale Horizontal Subsurface Flow Constructed Wetland Treating Polluted River Water

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 865 ◽  
Author(s):  
Lei Zheng ◽  
Tingting Liu ◽  
En Xie ◽  
Mingxue Liu ◽  
Aizhong Ding ◽  
...  
Keyword(s):  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Human Life ◽  
Subsurface Flow ◽  
Full Scale ◽  
Subsurface Flow Constructed Wetland ◽  
Horizontal Subsurface Flow ◽  
Butyl Phthalate ◽  
Acid Esters ◽  
Phthalate Acid Esters

When used as highly produced chemicals and widely used plasticizers, Phthalate acid esters (PAEs) have potential risks to human life and the environment. In this study, to assess the distribution and fate of PAEs, specifically inside a full-scale horizontal subsurface flow constructed wetland, four PAEs including dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), and bis (2-ethylhexyl) phthalate (DEHP) were investigated. In effluent, PAEs concentration decreased 19.32% (DMP), 19.18% (DEP), 19.40% (DBP), and 48.56% (DEHP), respectively. Within the wetland, PAEs partitioned in water (0.18–1.12 μg/L, 35.38–64.92%), soil (0.44–5.08 μg/g, 1.02–31.33%), plant (0.68–48.6 μg/g, 0.85–36.54%), air and biological transformation (2.72–33.21%). The results indicated that soil and plant adsorption contributed to the majority of PAE removal, digesting DMP (19.32%), DEP (19.18%), DBP (19.40%), and DEHP (48.56%) in constructed wetlands. Moreover, the adsorption was affected by both octanol/water partition coefficient (Kow) and transpiration stream concentration factors (TSCF). This work, for the first time, revealed the partition and fate of PAEs in constructed wetlands to the best of our knowledge.

scholarly journals PERFORMANCE AND SHORT TERM DURABILITY OF PALM KERNEL SHELL AS A SUBSTRATE MATERIAL IN A PILOT HORIZONTAL SUBSURFACE FLOW CONSTRUCTED WETLAND TREATING SLAUGHTERHOUSE WASTEWATER

2018 ◽  
Vol 4 (0) ◽  
Author(s):  
Nelson Mbanefo Okoye ◽  
Chimaobi Nnaemeka Madubuike ◽  
Ifeanyi Uba Nwuba ◽  
Sampson Nonso Ozokoli ◽  
Boniface Obi Ugwuishiwu
Keyword(s):  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Subsurface Flow ◽  
Palm Kernel ◽  
Typha Latifolia ◽  
Substrate Material ◽  
Slaughterhouse Wastewater ◽  
Palm Kernel Shell ◽  
Subsurface Flow Constructed Wetland ◽  
Horizontal Subsurface Flow

Wastewater treatment using constructed wetlands is one of the effective and low-cost technologies to improve the quality of slaughterhouse effluent. This study was carried out to investigate the suitability of palm kernel shell as a substrate material for constructed wetlands treating slaughterhouse wastewater. Rhizomes of Thalia Geniculata and Typha Latifolia were grown in four pilot horizontal subsurface flow constructed wetland beds filled with palm kernel shell and grave, and their growth and treatment performance evaluated. The results of the study showed that Thalia Geniculata survives and proliferates in palm kernel shell bed. The mean removal rates of 72.81% (BOD5), 89.87% (TSS), 39.42% (NH4-N), 60.79% (NO3-N) and 42.52% (PO43-) for the palm kernel shell were comparable to the values obtained for the gravel bed. The study proved that palm kernel shell, as a substrate material in constructed wetlands had the potentials to sustain the growth of some macrophytes, as well as the capacity to remove contaminants from wastewater.

scholarly journals Removal of Emerging Pollutants in Horizontal Subsurface Flow and Vertical Flow Pilot-Scale Constructed Wetlands

Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2200
Author(s):  
Georgios D. Gikas ◽  
Vassiliki A. Papaevangelou ◽  
Vassilios A. Tsihrintzis ◽  
Maria Antonopoulou ◽  
Ioannis K. Konstantinou
Keyword(s):  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Subsurface Flow ◽  
Pilot Scale ◽  
Emerging Pollutants ◽  
Feeding Strategies ◽  
Vertical Flow ◽  
University Campus ◽  
Removal Efficiencies ◽  
Horizontal Subsurface Flow

We assessed constructed wetland (CW) performance in the removal of six emerging pollutants (EPs) from university campus wastewater. The EPs considered were: diethyl phthalate (DEP), di-isobutyl phthalate (DIBP), di-n-octyl phthalate (DNOP), bis(2-ehtylxexyl) phthalate (DEHP), tris(1-chloro-2-propyl) phosphate (TCPP) and caffeine (CAF). Six pilot-scale CWs, i.e., three horizontal subsurface flow (HSF) and three vertical flow (VF), with different design configurations were used: two types of plants and one unplanted for both the HSF and the VF, two hydraulic retention times (HRT) for the HSF, and two wastewater feeding strategies for the VF units. The results showed that the median removals in the three HSF-CWs ranged between 84.3 and 99.9%, 79.0 and 95.7%, 91.4 and 99.7%, 72.2 and 81.0%, 99.1 and 99.6%, and 99.3 and 99.6% for DEP, DIBP, DNOP, DEHP, TCPP, and CAF, respectively. In the three VF-CWs, the median removal efficiencies range was 98.6–99.4%, 63.6–98.0%, 96.6–97.8%, 73.6–94.5%, 99.3–99.5% and 94.4–96.3% for DEP, DIBP, DNOP, DEHP, TCPP and CAF, respectively. The study indicates that biodegradation and adsorption onto substrate were the most prevalent removal routes of the target EPs in CWs.

Effects of sorption, sulphate reduction, and Phragmites australis on the removal of heavy metals in subsurface flow constructed wetland microcosms

2007 ◽  
Vol 56 (3) ◽  
pp. 193-198 ◽  
Author(s):  
E. Lesage ◽  
D.P.L. Rousseau ◽  
A. Van de Moortel ◽  
F.M.G. Tack ◽  
N. De Pauw ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Phragmites Australis ◽  
Constructed Wetland ◽  
Metal Removal ◽  
Subsurface Flow ◽  
High Strength ◽  
Sulphate Reduction ◽  
Separate Experiment ◽  
Subsurface Flow Constructed Wetland ◽  
Removal Of Heavy Metals

The removal of Co, Ni, Cu and Zn from synthetic industrial wastewater was studied in subsurface flow constructed wetland microcosms filled with gravel or a gravel/straw mixture. Half of the microcosms were planted with Phragmites australis and half were left unplanted. All microcosms received low-strength wastewater (1 mg L−1 of Co, Ni, and Zn, 0.5 mg L−1 Cu, 2,000 mg L−1 SO4) during seven 14-day incubation batches. The pore water was regularly monitored at two depths for heavy metals, sulphate, organic carbon and redox potential. Sorption properties of gravel and straw were assessed in a separate experiment. A second series of seven incubation batches with high-strength wastewater (10 mg L−1 of each metal, 2,000 mg L−1 SO4) was then applied to saturate the substrate. Glucose was added to the gravel microcosms together with the high-strength wastewater. Sorption processes were responsible for metal removal during start-up, with the highest removal efficiencies in the gravel microcosms. The lower initial efficiencies in the gravel/straw microcosms were presumably caused by the decomposition of straw. However, after establishment of anaerobic conditions (Eh∼−200 mV), precipitation as metal sulphides provided an additional removal pathway in the gravel/straw microcosms. The addition of glucose to gravel microcosms enhanced sulphate reduction and metal removal, although Phragmites australis negatively affected these processes in the top-layer of all microcosms.

scholarly journals Greenhouse Gas Emissions From a Horizontal Subsurface Flow Constructed Wetland for Wastewater Treatment in Small Villages

2020 ◽  
Keyword(s):  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Subsurface Flow ◽  
Green Technology ◽  
Nitrous Oxide Emissions ◽  
Gas Emissions ◽  
Horizontal Subsurface Flow ◽  
One Year

<p>Constructed wetlands with a land-intensive, low energy and less operational requirement have been used as a sustainable green technology for treating wastewaters. But are constructed wetlands sustainable? The objectives of the present study are to evaluate one year monitored horizontal subsurface flow constructed wetland’s treatment efficiency from May 2017 to May 2018 and to estimate the greenhouse gas emissions (GHG) in terms of N2O and CH4. As field data show the average removal efficiencies are low but are all within the effluent standard for water quality. One year average of high suspended solids (91.1 %), high total nitrogen (%85.6), low total phosphorous (22.4% TP), low organic matter (43.1% BOD5 &amp; 35.9% COD) removals are obtained. One year average methane and nitrous oxide emissions at the outlet of constructed wetland are calculated as 17.52 and 0.29 kg/d, respectively.</p>

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