The Microbiology Associated with Glycol Removal in Constructed Wetlands

1999 ◽  
Vol 40 (3) ◽  
pp. 99-107 ◽  
Author(s):  
S. Chong ◽  
H. Garelick ◽  
D. M. Revitt ◽  
R. B. E. Shutes ◽  
P. Worrall ◽  
...  

During the winter months, the application of large quantities of glycol based anti- and de-icers to aircraft and runways poses a serious threat to receiving waters because of their toxicity and BOD effect. The orthodox approach has been to store runoff waters in aerated lagoons before discharge to receiving waters or to sewage treatment works. In the development of a pollution control strategy for Heathrow Airport Ltd. (HAL), a combination of alternative methods for treatment are being considered, and amongst these is the use of constructed wetlands on a pilot scale. Results from this study indicate that most constructed wetland plants and substrate micro-organism populations throughout the beds are not adversely affected by airport runoff or exposure to shock-loads of glycols at initial total concentrations of 1180mg/1 and 632mg/1 in the subsurface and surface flow reedbeds respectively. Apart from Typha spp, the aquatic macrophytes have adapted well to the exposure to airport runoff. Glycol removal efficiencies have improved as the beds have matured, and average removal efficiencies of 78% for the sub-surface system and 54% for the surface system have been recorded. Complimentary monitoring of substrate micro-organism populations prior to and after glycol dosings have shown that aerobic microbial groups of bacteria, fungi and actinomyctes, are present in higher numbers (105−107 CFU/g substrate dry weight) than their anaerobic counterparts (103−105 CFU/g substrate dry weight). In the laboratory, studies have shown fungi and bacteria to be most tolerant of glycol, with several strains able to utilise these compounds.

1997 ◽  
Vol 36 (8-9) ◽  
pp. 385-390 ◽  
Author(s):  
D. M. Revitt ◽  
R. B. E. Shutes ◽  
N. R. Llewellyn ◽  
P. Worrall

The relative efficiencies of pollutant removal from airport runoff by three different designs of pilot scale reedbed treatment systems located at Heathrow airport are described. The sub-surface flow and surface flow systems generally performed more effectively than the rafted systems for reduction of BOD, COD, total ammonia, nitrate, phosphate and metal concentrations. The variable removal efficiencies are explained in terms of the physical, chemical and biological processes which are relevant to each reedbed system.


2013 ◽  
Vol 68 (10) ◽  
pp. 2271-2278 ◽  
Author(s):  
Israa Abdulwahab Al-Baldawi ◽  
Siti Rozaimah Sheikh Abdullah ◽  
Nurina Anuar ◽  
Fatihah Suja ◽  
Mushrifah Idris

One of the appropriate development technology options for the treatment of wastewater contaminated with diesel is constructed wetlands (CWs). Throughout 72 days of exposure, sampling was carried out for monitoring of physical parameters, plant growth and the efficiency of total petroleum hydrocarbon (TPH) removal, as an indication for diesel contamination, to assess the pilot-scale performance. Four pilot CWs with a horizontal sub-surface flow system were applied using the bulrush of Scirpus grossus. The CWs were loaded with different diesel concentrations of 0, 0.1, 0.2 and 0.25% (Vdiesel/Vwater). The TPH removal efficiencies were 82, 71, and 67% at the end of 72 days for diesel concentrations of 0.1, 0.2, and 0.25% respectively. In addition, the high removal efficiency of total suspended solids and chemical oxygen demand (COD) were 100 and 75.4% respectively, for a diesel concentration of 0.1%. It was concluded that S. grossus is a potential plant that can be used in a well-operated CW for restoring 0.1% diesel-contaminated water.


2011 ◽  
Vol 6 (3) ◽  
Author(s):  
C. T. Avellán ◽  
D. P. L. Rousseau ◽  
P. N. L. Lens

The 3600 dairy farms in south-western Uruguay, with about 750,000 cows in 2008, play an important economic role. Only about 200 of the farms have a sewage treatment system, since no legal regulations for the disposal of effluents exist, the cost of construction is high and neither direct benefits nor incentives are given. The current systems are mainly lagoons that often lack maintenance, resulting in the eutrophication of rivers. One of our goals was to implement a low cost, robust surface flow constructed wetland using native plants, in order to test the acceptance and willingness to pay of the farmers and to see if the effluent water quality met the national standards even if operating under the lack of maintenance. Within a small catchment, 6 farmers attended a seminar series on water(shed) quality, importance of wetlands and sewage treatment options, explaining the functioning of constructed wetlands and the costs of construction. One of the farmers decided to construct a double lagoon system followed by a surface flow CW using Scirpus americanus. However, construction of the ponds occurred by the farmer himself resulting in inadequate dimensioning. The exceptionally dry summer 2008/2009 also delayed planting but by now plants have established themselves and other emergent macrophytes have followed. So far visual water quality as well as biodiversity has improved. Furthermore, farmers and technicians have become interested in the use of CW and other implementations are envisioned. Also, the legislation on dairy farm effluent is about to change which will boost the necessity for all kinds of sewage systems.


2021 ◽  
Vol 13 (22) ◽  
pp. 12456
Author(s):  
Tao Wang ◽  
Liping Xiao ◽  
Hongbin Lu ◽  
Shaoyong Lu ◽  
Xiaoliang Zhao ◽  
...  

The quality of micropolluted water is unstable and its substrate concentration fluctuates greatly. The goal is to predict the concentration effect on the treatment of nitrogen in a river with an actual low C/N ratio for the proposed full-scale Xiaoyi River estuary wetland, so that the wetland project can operate stably and perform the water purification function effectively in the long term. Two pilot-scale multistage constructed wetland–pond (MCWP) systems (S1 and S2, respectively) based on actual engineering with the same “front ecological oxidation ponds, two-stage horizontal subsurface flow constructed wetlands and surface flow constructed wetlands (SFCWs) as the core and postsubmerged plant ponds” as the planned process were constructed to investigate the effect of different influent permanganate indexes (CODMn) and total nitrogen (TN) contents on nitrogen removal from micropolluted river water with a fixed C/N ratio from summer to winter in the field. The results indicate that the TN removal rate in the S1 and S2 systems was significant (19.56% and 34.84%, respectively). During the process of treating this micropolluted water with a fixed C/N ratio, the influent of S2 with a higher CODMn concentration was conducive to the removal of TN. The TN removal rate in S2 was significantly affected by the daily highest temperature. There was significant nitrogen removal efficiency in the SFCWs. The C/N ratio was a major determinant influencing the nitrogen removal rate in the SFCWs. The organic matter release phenomenon in SFCWs with high-density planting played an essential role in alleviating the lack of carbon sources in the influent. This research strongly supports the rule that there is seasonal nitrogen removal in the MCWPs under different influent substrate concentrations, which is of guiding significance for practical engineering.


2020 ◽  
Vol 24 (06) ◽  
pp. 91-102
Author(s):  
Zahraa S. Aswad ◽  
◽  
Ahmed H. Ali ◽  
Nadia M. Al-Mhana ◽  
◽  
...  

A vertical subsurface flow constructed wetland (VSSFCW) and a free surface flow constructed wetland (FSFCW) were set for the objective of comparison the performance of two systems in order to make a decision of the better one for future installation of wastewater treatment system and power generation. Both of the constructed wetlands were planted with Cyperus Alternifolius. During the observation period (19 days or 456 hours), environmental conditions such as pH, temperature, total chemical oxygen demand (COD), phosphate (PO4), nitrate (NO3) ,total suspended solids (TSS), total dissolved solids (TDS), Pb, Cu, and Cd removal efficiencies of the systems were determined. According to the results, final removal efficiencies for the VSSF and FWSF, respectively, were: COD (94.3% and 94.3%),PO4 (84.3% and 75.3%), NO3 (100% and 100%), TSS (96.8% and 85.6%), Pb (65.8% and 81.4%), Cu (more than 94.7% and 89.4%), Cd (85.7% and 88%). The treatment performances of the VSSF were better than that of the FWSF with regard to the removal of suspended solids and nutrients. In FWSF systems, electricity generation performed better than VSSF of 31.4 mV especially with batch system during one wastewater feed is loaded among all of the nineteen days with maximum voltage of 33.7 mV and decreased gradually as oxygen depletion in cathode chamber and less metabolism processes has occurred.


2005 ◽  
Vol 51 (11) ◽  
pp. 175-181 ◽  
Author(s):  
B. Tunçsiper ◽  
S.Ç. Ayaz ◽  
L. Akça ◽  
A. Samsunlu

In this study, nitrogen removal was investigated in pilot-scale subsurface flow (SSF) and in free water surface flow (FWS) constructed wetlands installed in the campus of TUBITAK-Marmara Research Center, Gebze, near Istanbul, Turkey. The main purposes of this study are to apply constructed wetlands for the protection of water reservoirs and to reuse wastewater. Experiments were carried out at continuous flow reactors. The effects of the type of plants on the removal were investigated by using emergent (Canna, Cyperus, Typhia spp., Phragmites spp., Juncus, Poaceae, Paspalum and Iris.), submerged (Elodea, Egeria) and floating (Pistia, Salvina and Lemna) marsh plants at different conditions. During the study period HLRs were 30, 50, 70, 80 and 120 L m2 d−1 respectively. The average annual NH4-N, NO3-N, organic N and TN treatment efficiencies in SSF and FWS wetlands are 81% and 68%, 37% and 49%, 75% and 68%, 47% and 53%, respectively. Nitrification, denitrification and ammonification rate constant (k20) values in SSF and FWS systems have been found as 0.898 d−1 and 0.541 d−1, 0.488 d−1 and 0.502 d−1, 0.986 d−1 and 0.908 respectively. Two types of the models (first-order plug flow and multiple regression) were tried to estimate the system performances


2011 ◽  
Vol 6 (3) ◽  
Author(s):  
C. H. Sim ◽  
H. S. Eikaas ◽  
S. H. Chan ◽  
J. Gan

Five native plant species (Typha angustifolia, Scirpus mucronatus, Lepironia articulata, Eleocharis dulcis and Phragmites karka) were investigated for their nutrient removal efficiencies in shallow pond systems in Sg Buloh Wetland Reserve with water depth 0.12-0.30 m of a total 160 m2 in area size. The project aimed to investigate nutrient removal rates, removal efficiencies, nutrient storage in plant biomass, and plant growth. Pond water quality before and after planting in fully vegetated ponds improved significantly at 24.4% TP and 64.4% TN reduction in Pond 6. Scirpus mucronatus, Typha angustifolia, Lepironia articulata and Eleocharis dulcis showed high growth rates. Phragmites karka showed low growth rate due to pest attack by aphids. Nutrient concentration in stem/leaf samples of the 5 species were within the ranges of 1% to 3% of dry weight for nitrogen and 0.1% to 0.3% of dry weight for phosphorus. Average daily mass removal rates ranged from 3.5-9.6 kg P ha−1 day−1 and 13.5-33.5 kg N ha−1 day−1. This field trial showed that the 4 species Lepironia articulata, Eleocharis dulcis, Typha angustifolia and Scirpus mucronatus are suitable species in surface flow wetland or shallow pond systems for nutrient removal in tropical environments.


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