Fecal coliform removal in a lightly loaded surface-flow constructed treatment wetland polishing agricultural runoff

2013 ◽  
Vol 68 (4) ◽  
pp. 909-915 ◽  
Author(s):  
Marc W. Beutel ◽  
Victoria Whritenour ◽  
Elaine Brouillard
Keyword(s):  
Retention Time ◽  
Fecal Coliform ◽  
Hydraulic Retention Time ◽  
Agricultural Runoff ◽  
Surface Flow ◽  
Treatment Wetland ◽  
Loss Mechanism ◽  
Sedimentation Basin ◽  
The North ◽  
Loaded Surface

Constructed treatment wetlands can be an effective and sustainable method to remove pathogens that pose health risks from agricultural runoff. This study evaluated the removal of fecal coliform (FC) from agricultural runoff in a lightly loaded surface-flow treatment wetland prior to discharge to the Yakima River, Washington State, USA. The 1.6 ha system consisted of a sedimentation basin (1.4 d hydraulic retention time) followed by two wetlands (5–6 d hydraulic retention time). FC in inflow ranged from 100 to 1,000 cfu/100 mL. Mean annual FC log-removal in the sedimentation basin was 0.66 ± 0.17 (mean plus/minus standard deviation; n = 7). However, there was a comparable production of FC within the two wetlands where annual log-removal averaged −0.71 ± 0.39 in the north wetland and −0.57 ± 0.17 in the south wetland. FC removal in the sedimentation basin weakly correlated with turbidity removal (R2 = 0.13, p < 0.01, n = 61), suggesting that settling was an important FC loss mechanism. FC removal in the wetlands negatively correlated with temperature (R2 = 0.27–0.33, p < 0.01, n = 26) indicating that survival and/or reproduction was an important FC production mechanism. Muskrat colonization in the wetlands in 2007 and 2008 corresponded with a marked increase in FC in wetland outflow. Results suggest that, regardless of the presence of muskrats, sedimentation basins alone are more effective than a combined sedimentation basin–wetland system in removing FC from dilute agricultural runoff.

Removal of Total Coliform and TSS for Hospital Wastewater by Optimizing the Role of Typha Angustifolia and Fine Sand-Gravel Media in Horizontal Sub Surface Flow Constructed Wetland

2021 ◽  
Vol 12 (1) ◽  
pp. 20-31
Author(s):  
Abdul Gani Akhmad
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Fine Sand ◽  
Pilot Scale ◽  
Total Coliform ◽  
Surface Flow ◽  
Pollutant Removal ◽  
Typha Angustifolia ◽  
Hospital Wastewater

This study aims to evaluate the performance of a pilot-scale HSSF-CW utilizing Typha angustifolia and fine sand-gravel media in removing total coliform and TSS from hospital wastewater. Three pilot-scale HSSF-CW cells measuring 1.00 x 0.45 x 0.35 m3 were filled with gravel sand media with a diameter of 5 - 8 mm as high as 35 cm with a submerged media depth of 0.30 m. There were three treatments, namely the first cell (CW1) without plants, the second cell (CW2) was planted with a density of 12 Typha angustifolia plants, and the third cell (CW3) was planted with a density of 24 Typha angustifolia plants. The three HSSF-CW cells received the same wastewater load with total coliform and TSS contents of 91000 MPN / 100 mg and 53 mg / L, respectively, with Hydraulic Loading Rates 3,375 m3 per day. Wastewater was recirculated continuously to achieve the equivalent HSSF-CW area requirement. The experimental results show that the performance of CW3 is more efficient than CW1 and CW2 in total coliform and TSS removal for hospital wastewater. The pollutant removal efficiency at CW3 reached 91.76% for total coliform with one day hydraulic retention time and 81.00% for TSS with two days of hydraulic retention time. This study concludes that the HSSF-CW system using sand-gravel media with a diameter of 5 - 8 mm with a submerged media depth of 0.30 m and planted with Typha angustifolia with a tighter spacing proved to be more efficient in removing total coliform and TSS from hospital wastewater.

The effect of hydraulic retention time on the removal of pollutants from sewage treatment plant effluent in a surface-flow wetland system

Wetlands ◽  
10.1672/13 ◽  
2005 ◽  
Vol 25 (2) ◽  
pp. 375-391 ◽  
Author(s):  
Sylvia Toet ◽  
Richard S. P. Logtestijn ◽  
Ruud Kampf ◽  
Michiel Schreijer ◽  
Jos T. A. Verhoeven
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Surface Flow ◽  
Wetland System

scholarly journals ANALYSIS OF A WETLAND SYSTEM IN THE POST-TREATMENT OF WASTEWATER

2014 ◽  
Vol 3 (1) ◽  
Author(s):  
Carlos Eduardo Zacarkim ◽  
Luciano Caetano De Oliveira ◽  
Nayara Symanski ◽  
Fernando Rodolfo Espinoza Quinõnes ◽  
Soraya Moreno Palácio ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Retention Time ◽  
Treatment Process ◽  
Hydraulic Retention Time ◽  
Low Cost ◽  
Surface Flow ◽  
Wastewater Treatment Process ◽  
Wetland System ◽  
Simple Technology ◽  
Conventional Systems

The study was based on a surface flow wetland system, using the macrophyte Eicchornia crassipes. The use of wetlands as an alternative in the wastewater treatment process has been employed due to the handling and simple technology, addition to the low cost compared to conventional systems. Three hydraulic retention times, they are 4, 6 and 8 days were analyzed. In general the system showed significant results in relation to removals of nutrients for all TRH reviews, where the hydraulic retention time of 6 days achieved the best performance. The proposed system achieved 79.91% reductions for COD, 83.51% of Total Phosphorus, Total Nitrogen 67.93%, 87.7% chromium and 52% Sulfur.

Study on Surface Flow Constructed Wetland Treating Slightly Polluted River Water in the High Latitude and Cold Region

2013 ◽  
Vol 726-731 ◽  
pp. 3501-3505 ◽  
Author(s):  
Zhi Gang Zhao ◽  
Yong Xiang Zhang ◽  
Shuo Jia Peng ◽  
Zhi Yuan Li ◽  
Wei Yao Li
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Surface Flow ◽  
Polluted Water ◽  
Cold Region ◽  
Polluted River ◽  
N Removal ◽  
Wetland System ◽  
Removal Efficiencies ◽  
Effects Of Temperature

Surface flow wetland with Reed planted in it was employed to treat micro-polluted water in Xinkai river, and effects of temperature, hydraulic retention time and growth of plants on the performance of surface flow wetland were studied. The results showed that COD removal of surface flow wetland was influenced by growth of plants and temperature, hydraulic retention time affected the performance of surface flow wetland obviously. NH4+-N removal of surface flow wetland was excellent and stable. Most of the area of the wetland system was under anaerobic or anoxic, Concentration of NO2--N and NO3--N in effluent stayed low. The denitrification was fully conducted but nitrification became a constraining factor. TP removal performance of surface flow wetland was ordinary. When Temperature was greater than 16°C, the hydraulic retention time was greater than the 3d and plants grew well, removal efficiencies of CODNH4+-N and TP were 22.45%,70.10% and 55.80% with concentration below 30.21mg/L1.82mg/L and 0.36mg/L, and the standards of Surface Water Grade V were satisfied.

Reducing hydraulic short-circuiting in maturation ponds to maximize pathogen removal using channels and wind breaks

2003 ◽  
Vol 48 (2) ◽  
pp. 153-162 ◽  
Author(s):  
B.J. Lloyd ◽  
C.A. Vorkas ◽  
R.K. Guganesharajah
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Plug Flow ◽  
Surface Flow ◽  
Faecal Coliform ◽  
Coliform Bacteria ◽  
Faecal Coliforms ◽  
Log Reduction ◽  
Time Flow ◽  
The Impact

This paper reports the impact of four sequential maturation pond interventions on the removal of thermotolerant “faecal” coliform bacteria at a full scale WSP system in tropical Colombia. Each intervention was designed to increase hydraulic retention time and was followed by continuous physico-chemical logging and meteorological monitoring, and simultaneous tracer studies to define hydraulic retention time, flow paths and dispersion. Inlet and outlet monitoring showed that, primarily due to hydraulic short-circuiting, the open maturation pond only achieved a 90% reduction in thermotolerant “faecal” coliforms. By contrast, an in-pond batch decay rate study for thermotolerant faecal coliforms showed that a 1 log (90%) reduction was achieved every 24 hours for 4 days at 26°C, so that the maximum theoretical efficiency would be a 2.6 log reduction (99.7%) if hydraulic efficiency was perfect for plug flow. The second intervention was the conversion of the maturation pond to a parallel series of three open channels to attempt to control short-circuiting and convert to plug flow. The channels raised performance to 96%. The introduction of top baffles, at the end of the first and second channels, to attempt to further reduce the effect of surface and sub-surface flow on short-circuiting, actually reduced performance to 92.64%, and were removed. The final intervention, a 2.1 m high wind break around the maturation channels raised efficiency to 98.13%; this performance is almost a half log (0.47) greater than the efficiency (95.1%) predicted from Marais' equation for a completely mixed reactor, and 0.77 log greater than recorded in the open pond. The results have fundamental implications for improving WSP efficiency, for meeting re-use guidelines, for savings in land area and improvement of design of WSPs; they also highlight short-comings in the indiscriminate use of the Marais design equation for faecal coliform removal.

scholarly journals Treatment of Piggery Wastewater by Three Grass Species Growing in a Constructed Wetland

2017 ◽  
pp. 75-83 ◽  
Author(s):  
Supaporn Pongthornpruek
Keyword(s):  
Wastewater Treatment ◽  
Constructed Wetland ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Oxygen Demand ◽  
Surface Flow ◽  
Grass Species ◽  
Vetiver Grass ◽  
Piggery Wastewater ◽  
Wastewater Quality

The study aimed to investigate the efficiency of piggery wastewater treatment by the surface flow constructed wetland with three different grass species; bulrush (Scirpus spp.), cattail (Typha angustifoliaL.), and vetiver grass (Vetiveria zizanioides L.). All pilot units were used for wastewater treatment by the flowing surface water system, giving a system carrying capacity of several 0.18 m3 d-1 of HLR with a 5 day hydraulic retention time (HRT). The results showed that the cattail pilot showed improvement in several wastewater quality indicators: biochemical oxygen demand (BOD), chemical oxygen demand (COD) and total kjeldahl nitrogen (TKN) with efficiencies of 80.59, 84.11 and 88.08 %, respectively. The vetiver grass was most efficient of the three grasses in treating total phosphorus (TP). The efficiency of constructed wetland treatment using bulrush and cattail for TP was not significantly different. The piggery wastewater treatment with a 5 day HRT was able to reduce the dirtiness in wastewater but ultimately was unable to meet the wastewater quality standard. Thus, the periods for hydraulic retention time should be increased to establish the optimal retention time for effective wastewater treatment.

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