Design, construction and performance of a horizontal subsurface flow wetland system in Australia

2013 ◽  
Vol 68 (9) ◽  
pp. 1920-1925 ◽  
Author(s):  
Lise M. W. Bolton ◽  
Keith G. E. Bolton
Keyword(s):  
Subsurface Flow ◽  
Oxygen Demand ◽  
Extended Period ◽  
Secondary Level ◽  
Social Needs ◽  
Septic Tank ◽  
In Series ◽  
Horizontal Subsurface Flow ◽  
High Level ◽  
Wetland Cell

Malabugilmah is a remote Aboriginal community located in Clarence Valley, Northern NSW, Australia. In 2006, seven horizontal subsurface flow wetland clusters consisting of 3 m × 2 m wetland cells in series were designed and constructed to treat septic tank effluent to a secondary level (Total Suspended Solids (TSS) < 30 mg/L and Biochemical Oxygen Demand (BOD5) <20 mg/L) and achieve >50% Total Nitrogen (TN) reduction, no net Total Phosphorus (TP) export and ≥99.9% Faecal Coliform (FC) reduction. The wetland cell configuration allowed the wetlands to be located on steeper terrain, enabling effluent to be treated to a secondary level without the use of pumps. In addition to the water quality targets, the wetlands were designed and constructed to satisfy environmental, economic and social needs of the community. The wetland systems were planted with a local Australian wetland tree species which has become well established. Two wetland clusters have been monitored over the last 4 years. The wetlands have demonstrated to be robust over time, providing a high level of secondary treatment over an extended period.

Effects of intermittent loading on nitrogen removal in horizontal subsurface flow wetlands

2010 ◽  
Vol 62 (8) ◽  
pp. 1865-1871 ◽  
Author(s):  
Margaret G. Forbes ◽  
Joe C. Yelderman ◽  
Tina Potterton ◽  
Robert D. Doyle
Keyword(s):  
Control Cell ◽  
Subsurface Flow ◽  
Ammonia Removal ◽  
Septic Tank ◽  
N Removal ◽  
Order Of Magnitude ◽  
Septic Tank Effluent ◽  
Horizontal Subsurface Flow ◽  
Expanded Shale ◽  
Wetland Cell

Removal of CBOD5 and nitrogen from septic tank effluent was evaluated in four horizontal subsurface flow (HSSF) wetlands. An intermittently loaded cell was compared to a continuously loaded control cell, with both treatments receiving the same weekly volume. The intermittent cell was rapidly drained and “rested” for 24-hr, then refilled in steps, twice weekly. Two media with different particle sizes but similar porosities were also compared. The two media, light weight expanded shale and gravel, were both continuously loaded. As hypothesized, the wetland cell that was intermittently loaded had higher dissolved oxygen, greater ammonia removal, and greater nitrate production than the continuously loaded cells. Areal NH3-N removal for the intermittently loaded cell was 0.90 g m−2 d−1 compared to 0.47 g m−2 d−1 for the control. Ammonia removal was also higher in continuously loaded gravel cells than in cells with expanded shale. Ammonia-N removal was an order of magnitude lower in a similar SSF wetland that had been in operation for 3 years. However, CBOD5, total suspended solids, and total nitrogen did not vary substantially among the treatments.

scholarly journals Post-treatment of tannery wastewater using pilot scale horizontal subsurface flow constructed wetlands (polishing)

2017 ◽  
Vol 77 (4) ◽  
pp. 988-998 ◽  
Author(s):  
Tadesse Alemu ◽  
Andualem Mekonnen ◽  
Seyoum Leta
Keyword(s):  
Removal Efficiency ◽  
Batch Reactor ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Surface Flow ◽  
Tannery Wastewater ◽  
Treated Effluent ◽  
Horizontal Subsurface Flow ◽  
Pollutants Removal

Abstract In the present study, a pilot scale horizontal subsurface flow constructed wetland (CW) system planted with Phragmites karka; longitudinal profile was studied. The wetland was fed with tannery wastewater, pretreated in a two-stage anaerobic digester followed by a sequence batch reactor. Samples from each CW were taken and analyzed using standard methods. The removal efficiency of the CW system in terms of biological oxygen demand (BOD), chemical oxygen demand (COD), Cr and total coliforms were 91.3%, 90%, 97.3% and 99%, respectively. The removal efficiency for TN, NO3− and NH4+-N were 77.7%, 66.3% and 67.7%, respectively. Similarly, the removal efficiency of SO42−, S2− and total suspended solids (TSS) were 71.8%, 88.7% and 81.2%, respectively. The concentration of COD, BOD, TN, NO3−N, NH4+-N, SO42 and S2− in the final treated effluent were 113.2 ± 52, 56 ± 18, 49.3 ± 13, 22.75 ± 20, 17.1 ± 6.75, 88 ± 120 and 0.4 ± 0.44 mg/L, respectively. Pollutants removal was decreased in the first 12 m and increased along the CW cells. P. karka development in the first cell of CW was poor, small in size and experiencing chlorosis, but clogging was higher in this area due to high organic matter settling, causing a partial surface flow. The performance of the pilot CW as a tertiary treatment showed that the effluent meets the permissible discharge standards.

Mass transfer approach and the designing of horizontal subsurface flow constructed wetland systems treating waste stabilisation pond effluent

2018 ◽  
Vol 78 (12) ◽  
pp. 2639-2646 ◽  
Author(s):  
Anita M. Rugaika ◽  
Damian Kajunguri ◽  
Rob Van Deun ◽  
Bart Van der Bruggen ◽  
Karoli N. Njau
Keyword(s):  
Mass Transfer ◽  
Constructed Wetlands ◽  
Rate Constants ◽  
Removal Rate ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Organic Load ◽  
Mass Transfer Effect ◽  
Horizontal Subsurface Flow

Abstract Pilot-scale constructed wetlands (CWs) that allowed wastewater to flow with high interstitial velocities in a controlled environment were used to evaluate the possibility of using mass transfer approach to design horizontal subsurface flow constructed wetlands (HSSF-CWs) treating waste stabilisation ponds (WSPs) effluent. Since CW design considers temperature which is irrelevant in tropics, mass transfer approach could improve the design. HSSF-CWs were operated in batch recycle mode as continuous stirred tank reactors (CSTR) at different interstitial velocities. The overall removal rate constants of chemical oxygen demand (COD) at various interstitial velocities were evaluated in mesocosms that received pretreated domestic wastewater. The mean overall removal rate constants were 0.43, 0.69, 0.74 and 0.73 d−1 corresponding to interstitial velocities of 15.43, 36, 56.57 and 72 md−1, respectively. Results showed that the interstitial velocities up to 36 md−1 represented a range where mass transfer effect was significant and, above it, insignificant to the COD removal process. Since WSPs effluent has high flow rates and low organic load, it is possible to induce high interstitial velocities in a HSSF-CW treating this effluent, without clogging and overflow. The performance of these HSSF for tertiary treatment in tropical areas could be improved by considering flow velocity when designing.

Performance of horizontal subsurface flow constructed wetland in the removal of tanninsA paper submitted to the Journal of Environmental Engineering and Science.

2010 ◽  
Vol 37 (3) ◽  
pp. 496-501 ◽  
Author(s):  
K.N. Njau ◽  
M. Renalda
Keyword(s):  
Removal Efficiency ◽  
Constructed Wetland ◽  
Control Cell ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Outlet Concentration ◽  
Cod Removal Efficiency ◽  
Subsurface Flow Constructed Wetland ◽  
Horizontal Subsurface Flow

A horizontal subsurface flow constructed wetland (HSSFCW) was employed to remove tannins from the effluent of a tannins extracting company. Two HSSFCW cells with hydraulic retention time (HRT) of 9 d and packed with limestone were used. One cell without macrophytes was used as a control, while the second cell was planted with Phragmites mauritianus . Results indicated that HSSFCW was capable of treating tannin wastewater that has been seeded with primary facultative pond sludge. Tannins and chemical oxygen demand (COD) removal efficiency of 95.9% and 90.6% with outlet concentration of 27 mg/L and 86 mg/L, respectively, were obtained in the planted cell; while the tannins and COD removal efficiency of 91.1% and 89.5% with outlet concentration of 57 mg/L and 96 mg/L, respectively, were obtained in the control cell.

scholarly journals Assessment of the technological reliability of a hybrid constructed wetland for wastewater treatment in a mountain eco-tourist farm in Poland

2017 ◽  
Vol 75 (11) ◽  
pp. 2649-2658 ◽  
Author(s):  
Andrzej Jucherski ◽  
Maria Nastawny ◽  
Andrzej Walczowski ◽  
Krzysztof Jóźwiakowski ◽  
Magdalena Gajewska
Keyword(s):  
Wastewater Treatment ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Operational Reliability ◽  
Septic Tank ◽  
Clay Material ◽  
Lognormal Distributions ◽  
Total Nitrogen Removal ◽  
High Level ◽  
Test Treatment

The aim of the present study was to assess the technological reliability of a domestic hybrid wastewater treatment installation consisting of a classic three-chambered (volume 6 m3) septic tank, a vertical flow trickling bed filled with granules of a calcinated clay material (KERAMZYT), a special wetland bed constructed on a slope, and a permeable pond used as a receiver. The test treatment plant was located at a mountain eco-tourist farm on the periphery of the spa municipality of Krynica-Zdrój, Poland. The plant's operational reliability in reducing the concentration of organic matter, measured as biochemical oxygen demand (BOD5) and chemical oxygen demand (COD), was 100% when modelled by both the Weibull and the lognormal distributions. The respective reliability values for total nitrogen removal were 76.8% and 77.0%, total suspended solids – 99.5% and 92.6%, and PO4-P – 98.2% and 95.2%, with the differences being negligible. The installation was characterized by a very high level of technological reliability when compared with other solutions of this type. The Weibull method employed for statistical evaluation of technological reliability can also be used for comparison purposes. From the ecological perspective, the facility presented in the study has proven to be an effective tool for protecting local aquifer areas.

Performance and behaviour of planted and unplanted units of a horizontal subsurface flow constructed wetland system treating municipal effluent from a UASB reactor

2013 ◽  
Vol 68 (7) ◽  
pp. 1495-1502 ◽  
Author(s):  
Jocilene Ferreira da Costa ◽  
André Cordeiro de Paoli ◽  
Martin Seidl ◽  
Marcos von Sperling
Keyword(s):  
Suspended Solids ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Post Treatment ◽  
Filter Medium ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Horizontal Subsurface Flow

A system composed of two horizontal subsurface flow constructed wetlands operating in parallel was evaluated for the post-treatment of UASB (upflow anaerobic sludge blanket) reactor effluent, for a population equivalent of 50 inhabitants per unit. One unit was planted with cattail (Typha latifolia) and the other was unplanted. The study was undertaken over a period of 4 years, comprising monitoring of influent and effluent constituents together with a full characterization of the behaviour of the units (tracer studies, mathematical modelling of chemical oxygen demand (COD) decay, characterization of solids in the filter medium). The mean value of the surface hydraulic load was 0.11 m3m−2d−1, and the theoretical hydraulic retention time was 1.1 d in each unit. Using tracer tests with 82Br, dispersion number (d) values of 0.084 and 0.079 for the planted and unplanted units were obtained, indicating low to moderate dispersion. The final effluent had excellent quality in terms of organic matter and suspended solids, but the system showed low capacity for nitrogen removal. Four-year mean effluent concentration values from the planted and unplanted units were, respectively: biochemical oxygen demand (BOD5): 25 and 23 mg L−1; COD: 50 and 55 mg L−1; total suspended solids (TSS): 9 and 9 mg L−1; N-ammonia: 27 and 28 mg L−1. The COD decay coefficient K for the traditional plug-flow model was 0.81 and 0.84 d−1 for the planted and unplanted units. Around 80% of the total solids present in the filter medium were inorganic, and most of them were present in the interstices rather than attached to the support medium. As an overall conclusion, horizontal subsurface flow wetlands can be a very suitable post-treatment method for municipal effluents from anaerobic reactors.

scholarly journals PHOSPHORUS REMOVAL FROM DOMESTIC WASTEWATER IN HORIZONTAL SUBSURFACE FLOW CONSTRUCTED WETLAND AFTER 8 YEARS OF OPERATION – A CASE STUDY

2004 ◽  
Vol 12 (4) ◽  
pp. 126-131 ◽  
Author(s):  
Agnieszka Karczmarczyk
Keyword(s):  
Sorption Capacity ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Phosphorus Sorption ◽  
Fine Grained ◽  
Hydraulic Load ◽  
Horizontal Subsurface Flow ◽  
Al And Fe Oxides

Horizontal subsurface flow constructed wetlands can effectively treat high levels of biochemical oxygen demand (BOD) and suspended solids. They are also effective as phosphorus trap but usually for a short time. This phenomenon was observed in the presented case study, an example of subsurface flow reed bed filled with “improved” site soil where it was assumed that the permeability of bed would increase as a result of reed penetration. Fine grained site soil was initially effective trap for phosphorus from wastewater. However, during operation clogging of bed media proceeded and phosphorus sorption capacity used up. In general, the longevity of subsurface flow wetlands as phosphorus sinks depends on the hydraulic load, phosphorus load and the type of the media used in bed construction. To be effective as phosphorus sorbent, substrate should contain high levels of Ca, Al and Fe oxides and possess suitable sorption capacity, quick time of reaction and suitable permeability.

Nutrient removal from on-site wastewater in horizontal subsurface flow constructed wetlands in Ireland

2011 ◽  
Vol 6 (3) ◽  
Author(s):  
N. O'Luanaigh ◽  
L. W. Gill
Keyword(s):  
Subsurface Flow ◽  
Septic Tank ◽  
Tertiary Treatment ◽  
Total N ◽  
Annual Total ◽  
Isotope Studies ◽  
Horizontal Subsurface Flow ◽  
Domestic Effluent ◽  
15N Stable Isotope ◽  
Total P

Two horizontal subsurface flow wetlands were constructed on separate sites in Ireland - one to provide secondary treatment and the other to provide a tertiary treatment for single house domestic effluent. A comprehensive analysis over three years provided a robust characterisation of the internal dynamics of the systems with respect to N and P removal. The removal of Total N was only 29% and 30% in the secondary and tertiary treatment wetlands respectively and revealed a drop off in performance over time with a higher release of org-N during summer periods. 15N stable isotope studies confirmed that 35% of the ammonium from the septic tank was passing straight through the process without taking part in any biogeochemical processes. However, the study showed that influent N in both wetlands was being biologically assimilated into organic nitrogen (biomass or plants) and then released again as soluble ammonium – so-called nitrogen “spiraling”. Removal of Total P in the wetlands averaged 45% and 28% respectively. The results also showed that if the annual above ground stem matter was completely removed it would only account for 8.4% and 1.3% of the annual total P-load to the respective wetlands. Accordingly the effluent PO4-P concentrations were still found to be >5 mg/l on average.

scholarly journals Efficiency of horizontal subsurface flow constructed wetlands cultivated with grasses of different root systems

2020 ◽  
Vol 20 (8) ◽  
pp. 3318-3329
Author(s):  
Fernanda Lamede Ferreira de Jesus ◽  
Antonio Teixeira de Matos ◽  
Mateus Pimentel de Matos
Keyword(s):  
Constructed Wetlands ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Root Systems ◽  
Sodium Concentration ◽  
Pollutant Removal ◽  
Organic Loading Rate ◽  
Vetiver Grass ◽  
Horizontal Subsurface Flow ◽  
Subsurface Flow Constructed Wetlands

Abstract The objective of this study was to evaluate the influence of stoloniferous and fasciculated root systems, of Tifton 85 and vetiver grass respectively, on pollutant removal for primary treatment of sewage in horizontal subsurface flow constructed wetlands (HSSF-CWs). For this, three HSSF-CWs measuring 4 m × 1 m × 0.25 m, filling with gneiss gravel # 0 (D60 of 7.0 mm and 48.4% porosity) as substrate, were used. One unit was cultivated with Tifton 85 grass (HSSFT-CW), one with vetiver grass (HSSFV-CW) and one remained uncultivated (HSSFC-CW) as a control. Sewage was applied at a flow rate of 0.53–0.80 m3 d−1, corresponding to an organic loading rate of approximately 350 kg ha−1 d−1 (biochemical oxygen demand – BOD), which resulted in a hydraulic retention time of 0.6–0.9 day. The HSSFV-CW was more efficient than the HSSFC-CW in removing dissolved solids (measured as electrical conductivity) and reducing the total suspended solids (TSS), BOD5, turbidity and sodium concentration, while the HSSFT-CW was not superior in any way. The results indicate that cultivation of vetiver grass provided increased efficiency for removing pollutants from sewage when compared with Tifton 85-grass, in the HSSF-CW.

Experimental study of a novel hybrid constructed wetland for water reuse and its application in Southern China

2011 ◽  
Vol 64 (11) ◽  
pp. 2177-2184 ◽  
Author(s):  
J. Zhai ◽  
H. W. Xiao ◽  
K. Kujawa-Roeleveld ◽  
Q. He ◽  
S. M. Kerstens
Keyword(s):  
Constructed Wetland ◽  
Water Reuse ◽  
Southern China ◽  
Sewage Treatment ◽  
Subsurface Flow ◽  
Circulatory System ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Municipal Sewage ◽  
Horizontal Subsurface Flow

A new type of hybrid constructed wetland (CW), consisting of both vertical-baffled flow wetland (VBFW) and horizontal subsurface flow wetland (HSFW), has been deployed in Southern China to naturally accelerate the removal of organic matter and nitrogen. The hybrid CW system is characterised by a combination of continuous baffled flow vertical wetland and ‘S’ pattern horizontal subsurface flow wetland with natural aeration ditches to increase the concentration of dissolved oxygen in the HSFW bed. An internal circulatory system from the HSFW effluent back to the VBFW may optionally be operated to enhance the biological denitrification effect. Cyperus alternifolius is the main macrophyte in the wetland bed. The performance of the hybrid CW was studied with a pilot-scale system and three full-scale systems for municipal sewage treatment in Southern China. The results suggest that this new hybrid CW can achieve removal efficiencies of chemical oxygen demand, suspended solids, ammonia nitrogen, total nitrogen, and total phosphorus of better than 83.6, 95.0, 71.7, 64.5 and 68.1% respectively, with a specific wetland bed area of 0.70–0.93 m2 PE−1. The mean effluent concentrations of these parameters would meet the regulatory discharge limits for wastewater treatment systems (GB18918, 2002) and reuse in the context of agricultural irrigation solutions in China.

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