Application of culture-independent methods to assess the bacteria removal efficiency of subsurface flow constructed wetlands

2007 ◽  
Vol 56 (3) ◽  
pp. 217-222 ◽  
Author(s):  
M. Alexandrino ◽  
E. Grohmann ◽  
R. Szewzyk ◽  
U. Szewzyk
Keyword(s):  
Removal Efficiency ◽  
Constructed Wetlands ◽  
Subsurface Flow ◽  
Current Standard ◽  
Enteropathogenic Bacteria ◽  
Culture Independent ◽  
Wastewater Quality ◽  
Subsurface Flow Constructed Wetlands ◽  
Wastewater Samples ◽  
Bacteria Removal

The bacteriologic treatment efficiency of vertical and horizontal subsurface flow constructed wetlands (SFCWs) was analysed in two multistage wastewater treatment systems by culture dependent and independent methods. When assessed with standard cultivation procedures, bacteria removal efficiency of the vertical and horizontal SFCWs was similar. However, microscopic enumerations of the wastewater bacteria after DNA staining revealed a completely different removal pattern: bacteria removal efficiency of the horizontal SFCWs was in general low and erratic, whereas the vertical SFCWs displayed high bacteria removal rates. The discrepancies in the results obtained by bacteria enumeration and cultivation was due to a strong decrease in bacterial culturability after treatment by the horizontal SFCWs, leading to overestimation of the real bacterial concentrations in these effluents. Additionally, a PCR based approach for the detection of the enteropathogenic bacteria Campylobacter jejuni and Yersinia enterocolitica was tested in the wastewater samples. The methods were specific and reproducible in the analysed samples and could be carried out within 12 h, proving very adequate as an alternative to cultivation. This work recommends a review of the current standard methodology for wastewater quality surveillance, as well as of the design of SFCW.

Improvement of domestic wastewater quality by subsurface flow constructed wetlands

2000 ◽  
Vol 75 (1) ◽  
pp. 19-25 ◽  
Author(s):  
Srinivasan Neralla ◽  
Richard W Weaver ◽  
Bruce J Lesikar ◽  
Russell A Persyn
Keyword(s):  
Constructed Wetlands ◽  
Subsurface Flow ◽  
Domestic Wastewater ◽  
Wastewater Quality ◽  
Subsurface Flow Constructed Wetlands

ENERGY PRODUCTION FROM WASTEWATER USING HORIZONTAL AND VERTICAL SUBSURFACE FLOW CONSTRUCTED WETLANDS

2014 ◽  
Vol 13 (10) ◽  
pp. 2517-2523 ◽  
Author(s):  
Jose Villasenor Camacho ◽  
Maria del Carmen Montano Vico ◽  
Manuel Andres ◽  
Rodrigo Rodrigo ◽  
Francisco Jesus Fernandez Morales ◽  
...  
Keyword(s):  
Constructed Wetlands ◽  
Energy Production ◽  
Subsurface Flow ◽  
Subsurface Flow Constructed Wetlands

Field-Scale Studies of Subsurface Flow Constructed Wetlands for Stormwater Quality Enhancement

1997 ◽  
Vol 32 (1) ◽  
pp. 101-118 ◽  
Author(s):  
Q.J. ROCHFORT ◽  
W.E. Watt ◽  
J. Marsalek ◽  
B.C. Anderson ◽  
A.A. Crowder
Keyword(s):  
Organic Carbon ◽  
Constructed Wetlands ◽  
Suspended Solids ◽  
Nutrient Loading ◽  
Subsurface Flow ◽  
Reaction Rates ◽  
Pollutant Removal ◽  
Order Kinetic ◽  
Dissolved Metals ◽  
Subsurface Flow Constructed Wetlands

Abstract Two subsurface flow constructed wetlands were tested for pollutant removal performance in conjunction with an on-line stormwater detention pond, in Kingston Township, Ontario. The 4.9 m2 wetland cells were filled with 9 mm limestone gravel, and planted with cattail, common reed and spike rush. Changes in nutrient (total organic carbon, PO43- and NH4+), suspended solids and metal (Cu, Pb, Zn) concentrations were used to assess performance. Contaminant removal occurred through a combination of physical, chemical and biological means. As with any biological system, variation in performance of stormwater wetlands can be expected to occur as a result of fluctuations in contaminant loading, contact time and ambient environmental conditions. Storm pond effluent was delivered in continuous flow through the wetlands (during baseflow and event conditions), with a detention time of 1 to 3 days. The wetlands were able to maintain removal rates of up to 39% for orthophosphate even during the more severe conditions of fall dieback. Average removal of suspended solids (46%) and dissolved metals (Cu 50%) remained similar throughout all tests. Organic carbon was reduced by less than 10% during these tests. Low nutrient levels in the pond effluent were supplemented by spiking with sources of carbon, nitrogen and phosphorus during pulsed loading conditions. Daily sampling produced a time series, which illustrated the rates of decline in concentration of nutrients. First order kinetic assimilation rates ranged from 1.7 d-1 for NH4002B to 0.12 d-1 for organic carbon, which were noticeably lower when compared with municipal and industrial wastewater treatment rates. Three methods of sizing stormwater wetlands (impervious surface area, volumetric load and kinetic reaction rates) were compared using the same design storm and data from this study. From this comparison it was seen that the kinetic sizing approach proved to be the most versatile, and allowed for adaptation to northern climatic conditions and anticipated nutrient loading.

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