Microbial indicator removal in onsite constructed wetlands for wastewater treatment in the southeastern U.S.

2001 ◽  
Vol 44 (11-12) ◽  
pp. 177-182 ◽  
Author(s):  
E.C. Barrett ◽  
M.D. Sobsey ◽  
C.H. House ◽  
K.D. White

Seven onsite constructed wetlands for wastewater treatment in the coastal plains of Alabama and North Carolina were studied from September 1997 to July 1998. Each site was examined for its ability to remove a range of fecal contamination indicators from settled wastewater. Indicator organisms include total and fecal coliforms, enterococci, Clostridium perfringens, and somatic and male-specific (F+) coliphages. Four identical domestic wastewater treatment sites in Alabama were evaluated. In these sites the Log10 geometric mean reductions ranged between 0.5 and 2.6 for total and fecal coliforms, 0.1 and 1.5 for enterococci, 1.2 to 2.7 for C. perfringens, -0.3 and 1.2 for somatic coliphages, and -0.2 and 2.2 for F+ coliphages. Three unique designs were examined in North Carolina. Log10 geometric mean reductions ranged between 0.8 to 4.2 for total and fecal coliforms, 0.3 to 2.9 for enterococci, 1.6 to 2.9 for C. perfringens, -0.2 and 2.8 for somatic coliphages, and -0.1 and 1.5 for F+ coliphages. Somatic and F+ coliphage detection was highly variable from month to month.

Water ◽  
2016 ◽  
Vol 8 (9) ◽  
pp. 365 ◽  
Author(s):  
Eleanor Butterworth ◽  
Andrew Richards ◽  
Mark Jones ◽  
Gabriella Mansi ◽  
Ezio Ranieri ◽  
...  

2001 ◽  
Vol 44 (11-12) ◽  
pp. 223-230 ◽  
Author(s):  
T.A. Stentström ◽  
A. Carlander

The interest in constructed wetlands for municipal wastewater and stormwater treatment has recently increased but data for the reduction efficiency of indicator organisms are often restricted to the water phase. In a full-scale wastewater wetland in Sweden fecal coliforms and enterococci were reduced by 97-99.9% and coliphages by approximately 70%. The factors affecting the reduction are however less well understood. In two full-scale wetlands, for stormwater and wastewater treatment, an assessment has been done of the particle associated fraction of indicator organisms. No significant differences in the particle-associated numbers were seen between the inlet and the outlet of the wetlands, but the amounts of sedimenting particles varied between the two sites. In the stormwater wetland the amount of sedimenting particles at the outlet was 3% of the amount at the inlet, while the wastewater wetland had much lower particle removal efficiency. The reduction of suspended particles seems to be the main factor for bacterial elimination from the water phase, governed by vegetation and design. In the sediment, survival of presumptive E.coli, fecal enterococci, Clostridium and coliphages were long with T90-values of 27, 27, 252 and 370 days, respectively. The organisms can however be reintroduced by resuspension. Viruses in the water phase may be of main concern for a risk assessment of receiving waters.


2001 ◽  
Vol 44 (11-12) ◽  
pp. 399-405 ◽  
Author(s):  
L. Behrends ◽  
L. Houke ◽  
E. Bailey ◽  
P. Jansen ◽  
D. Brown

Scientists at the Tennessee Valley Authority (TVA), and in collaboration with the U.S. Environmental Protection Agency (EPA), are continuing to develop and refine an innovative wastewater treatment system referred to as reciprocating subsurface-flow constructed wetlands. Reciprocation relates to patented improvements in the design and operation of paired subsurface-flow constructed wetlands, such that contiguous cells are filled and drained on a frequent and recurrent basis. This operating technique turns the entire wetland system into a fixed-film biological reactor, in which it is possible to control redox potential in alternating aerobic and anaerobic zones. Reciprocating systems enable manipulation of wastewater treatment functions by controlling such parameters as hydraulic retention time, frequency of reciprocation, reciprocation cycle time, depth of reciprocation, and size and composition of substrate. These improved wetland technologies have been used for treating municipal/domestic wastewater, high strength animal wastewater, and mixed wastewater streams containing acids, recalcitrant compounds, solvents, antifreeze compounds, heavy metals, explosives, and fertilizer nutrients. Results from selected treatability studies and field demonstrations will be summarized with respect to conceptual design and treatment efficacy.


2011 ◽  
Vol 63 (4) ◽  
pp. 654-659 ◽  
Author(s):  
F. Zurita ◽  
M. A. Belmont ◽  
J. De Anda ◽  
J. R. White

The aim of this study was to evaluate the domestic wastewater treatment efficiency as well as the survivability of commercially valuable ornamental plants in subsurface flow wetlands (SSFW) for domestic wastewater (DWW) treatment in laboratory and pilot wetland studies. The laboratory scale study included five different species (Zantedeschia aethiopica, Strelitzia reginae, Anthurium andreanum, Canna hybrids and Hemmerocallis dumortieri) that were evaluated in horizontal flow subsurface treatment cells. All the plants survived during the 6-month experimental period demonstrating high wetland nutrient treatment efficiency. In order to validate and expand these preliminary results, a pilot-scale wetland study was carried out in SSFWs under two different flow regimes (horizontal and vertical flow). Four ornamental species were tested during a 1-year period: Zantedeschia aethiopica, Strelitzia reginae, Anthurium andreanum and Agapanthus africanus. The removal efficiencies were significantly higher in the vertical subsurface-flow constructed wetlands (VFCW) for all pollutants, except for nitrate (NO3-N), total nitrogen (TN) and total suspended solids (TSS). These results show that it is feasible to use select non-wetland plants with high market value in SSFWs without reducing the efficiency of the wastewater treatment system, although future work should continue in order to apply this technology in a large scale. The added value of floriculture in treatment wetlands can help to promote the use of constructed wetlands (CW) for domestic wastewater treatment in developing countries where economical resources are scarce and water pollution with DWW is common.


2020 ◽  
pp. 559-587
Author(s):  
David de la Varga ◽  
Manuel Soto ◽  
Carlos Alberto Arias ◽  
Dion van Oirschot ◽  
Rene Kilian ◽  
...  

Constructed Wetlands (CWs) are low-cost and sustainable systems for wastewater treatment. Traditionally they have been used for urban and domestic wastewater treatment, but in the last two decades, the applications for industrial wastewater treatment increased due to the evolution of the technology and the extended research on the field. Nowadays, CWs have been applied to the treatment of different kind of wastewaters as such as refinery and petrochemical industry effluents, food industry effluents including abattoir, dairy, meat, fruit and vegetables processing industries, distillery and winery effluents, pulp and paper, textile, tannery, aquaculture, steel and mixed industrial effluents. In this chapter, the authors present the main types of CWs, explain how they work and the expected performances, and describe the principal applications of CWs for industrial wastewater treatment with particular attention to suspended solids, organic matter and nutrient removal. A review of these applications as well as some case studies will be discussed.


2017 ◽  
Vol 75 (10) ◽  
pp. 2268-2280 ◽  
Author(s):  
A. S. Tilak ◽  
Suhas P. Wani ◽  
A. Datta ◽  
M. D. Patil ◽  
M. Kaushal ◽  
...  

Ageratum conyzoides were evaluated in field scale subsurface flow constructed wetlands (CWs) to quantify its nitrogen (N) and phosphorus (P) uptake and compare with wetland plants (Pistia stratiotes, Typha latifolia and Canna indica). The two-field scale subsurface flow CWs, located in the International Crops Research Institute for Semi-Arid Tropics, received wastewater from an urban colony. The CW1 and CW2 had the same dimensions (length:10 m, width:3 m, total depth:1.5 m and sand and gravel:1 m), similar flow rates (3 m3/d), hydraulic loading rates (HLRs-10 cm/d) and hydraulic retention time (HRT-5 days) from July 2014–August 2015. The vegetation in both CWs consisted of Pistia stratiotes, Typha latifolia, Canna indica, and Ageratum conyzoides, respectively. The CW1 (% reduction with respect to concentrations) reduced total suspended solids (TSS) (68%), NH4-N (26%), NO3-N (30%), soluble reactive P (SRP) (20%), chemical oxygen demand (COD) (45%) and fecal coliforms (71%), while the CW2 (%-reduction with respect to concentrations) reduced TSS (63%), NH4-N (32%), NO3-N (26%), SRP (35%), COD (39%) and fecal coliforms (70%). Ageratum conyzoides can be used in combination with Pistia stratiotes, Typha latifolia and Canna indica to enhance removal of excessive N, P and fecal coliforms from domestic wastewater.


Sign in / Sign up

Export Citation Format

Share Document