Abstract
A global performance evaluation of an experimental Horizontal SubSurface Flow Constructed Wetlands (HSSF) was made after 6 years of functioning. This wetland is situated in French prealpine mountain, at 720 m elevation. The HSSF process treatment consists in a three-stage system dimensioned for 350 People Equivalent. Different helophytes were planted such as Typha latifolia, Phragmites australis and Scirpus maritimus. The mean hydraulic residence time for sewage was closed to 4–5 days, but in summer the mean pollutant residence time increases to 6 days due to an important evapotranspiration. There is no clogging of the gravel matrix and the hydraulic conductivity was very good and stabilized. Removal pollutant efficiency was determinate at each stages. There was a high removal of total suspended solids (TSS) all year around with an average of 95.6% (±3.6). More than 80% of removal occurred in the first stage. Physical processes (decantation, filtration) associated with biological oxidation were the principal factors of this removal. For COD and BOD5, removal efficiency in the first stage were close to 60% on average and more than 90% at the outlet of the wetland. These results are similar to those observed with SSFW in many cases. Influence of temperature seems very weak because there were no significant seasonal variations of the process efficiency. Minimum effluent quality standards (30 mg l−1 TSS; 120 mg l−1 COD; 40 mg l−1 BOD5) were always respected. In cold periods, nutrients uptake was reduced but remained up to 60% in average. Mean bacterial removal efficiency was about two order of magnitude (99%) but can reach up to five order of magnitude in summer. These cyclic variations follow a sinusoidal variation around an annual mean. Pollutants removals were correlated to their respective loadings and no limits has been observed except for nitrogen. These results confirm that SSFW, an ecotechnology, should be considered as an alternative to conventional treatment methods (activated sludge, fixed biofilm) for small communities even in mountainous area.
Similar content being viewed by others
References
AFNOR, 1995. Essais écotoxicologiques. Recueil des normes Françaises. AFNOR Edition. Paris: 387 pp.
Agence de l'Eau, 1999. Epuration des eaux usées par des filtres plantés de macrophytes. Etude Bibliographique Agence de l'Eau RMC, Lyon: 79 pp.
APHA, 1992. Standard Methods for the Examination of Water and Wastewater. 18th edn. American Public Health Association, Washington D.C.: 868 pp.
Batchelor, A., W. C. Scott & A. Wood, 1990. Constructed wetlands research in South Africa. In Cooper, P. F. & B. C. Findlater (eds), Constructed Wetlands in Water Pollution Control. Adv. Pollut. Control 11: 373–382.
Bhattarai, R. R. & D. M. Griffin, 1999. Results of tracer test in rock-plant filters. J. Env. Eng. 125: 117–125.
Boutin, C., A. Liénard & D. Esser, 1997. Development of a new generation of reed-bed filters in France: first results. Wat. Sci. Technol. 35: 315–322.
Brix, H., 1997. Do macrophytes play a role in constructed treatment wetlands? Wat. Sci. Technol. 35: 11–17.
Decamp, O., A. Warren & R. Sandoz, 1999. The role of ciliated protozoa in subsurface flow wetlands and their potential as bioindicators. Wat Sci. Technol. 40: 91–98.
Drizo, A., C. A. Frost, K. A. Smith & J. Grace, 1997. Phosphate and ammonium removal by constructed wetlands with horizontal subsurface flow using shale as a substrate. Wat. Sci. Technol. 35: 95–102.
Drizo, A., C. A. Frost, J. Grace & K. A. Smith, 2000. Phosphate and ammonium distribution in a pilot-scale constructed wetland with horizontal subsurface flow using shale as substrate. Wat. Res. 34: 2483–2490.
Goldminc, M. & C. Moncel, 1998. Une station d'épuration écologique, ça existe. Vie et Santé 1: 58–61.
Gopal, B., 1999. Natural and constructed wetlands for wastewater treatment: potentials and problems. Wat. Sci. Technol. 40: 27–35.
Green, M. B. & J. Upton, 1995. Constructed reed beds-appropriate technology for small communities. Wat. Sci. Technol. 32: 339–348.
Green, M. B., P. Griffin, J. K. Seabridge & D. Dhobie, 1997a. Removal of bacteria in subsurface flow wetlands. Wat. Sci. Technol. 35: 109–116.
Green, M., E. Friedler & I. Safrai, 1997b. Investigation of alternative method for nitrification in constructed wetlands. Wat. Sci. Technol. 35: 67–70.
Haberl, R., R. Perfler, & H. Mayer, 1995. Constructed wetlands in Europe. Wat. Sci. Technol. 32: 305–315.
Haberl, R., 1999. Constructed wetlands: a chance to solve wastewater problems in developing countries. Wat. Sci. Technol. 40: 11–17.
Kadlec, R. H. & R. L. Knight, 1996. Treatment Wetlands. Lewis Publishers, New York: 893 pp.
Kadlec, R. H., 1999. Chemical, physical and biological cycles in treatment wetlands. Wat. Sci. Technol. 40: 37–44.
Lakatos, G., M. K. Kiss & P. Juhasz, 1997. Application of constructed wetlands for wastewater treatment in Hungary.Wat. Sci. Technol. 35: 331–336.
Newman, J. M., J. C. Clausen & J. A. Neafsey, 2000. Seasonal performance of a wetland constructed to process dairy milkhouse wastewater in Connecticut. Ecol. Eng. 14: 181–189.
Ottava, V., J. Balcarova & J. Vymazal, 1997. Microbial characteristics of constructed wetlands. Wat. Sci. Technol. 35: 117–123.
Persson, J., N. L. G. Somes & H. F. Wong, 1999. Hydraulic efficiency of constructed wetlands and ponds. Wat. Sci. Technol. 40: 291–300.
Peterson, S. B. & J. M. Teal, 1996. The role of plants in ecologically engineered wastewater treatment systems. Ecol. Eng. 6: 137–148.
Reed, S. C. & D. S. Brown, 1995. Subsurface flow wetlands: a performance evaluation. Wat. Env. Res. 67: 244–248.
Rivera, F., A. Warren, E. Ramiraz, O. Decamp, P. Bonillo, E. Csallegos, A. Calderon & T. Sanchez, 1995. Removal of pathogens from wastewater by the root zone method (RZM). Wat. Sci. Technol. 32: 211–218.
Seidel, K., 1976. Macrophytes and water purification. In Tourbier, J. & R. W. Pierson, (eds), Biological Control of Water Pollution. University of Pensylvania Press, Philadelphia: 552–559.
Sauter, G. & K. Leonard, 1997. Wetland design methods for residential wastewater treatment. J. am. Wat. Res. Ass. 33: 155–162.
U.S. Environmental Protection Agency, 1993. Subsurface Flow Constructed Wetlands for wastewater treatment: a technology assessment. EPA/832/R-93-008.
Verhoeven, J. T. A. & A. F. M. Meuleman, 1998. Wetlands for wastewater treatment: opportunities and limitations. Ecol. Eng. 12: 5–12.
Vymazal, J., 1996. Constructed wetlands for wastewater treatment in the Czech Republic the first 5 years experience. Wat. Sci. Technol. 34: 159–164.
Vymazal, J., H. Brix, P. F. Cooper, M. B. Green, R. Haberl, 1998 Removal mechanisms and types of constructed wetlands. In Vymazal, J. H. (ed.), Constructed Wetlands for Wastewater Treatment in Europe. Backhuys Publishers, Leiden: 17–66.
White, K. D. & G. Burken, 1999. Natural treatment and On Site processes. Wat. Env. Res. 71: 676–685.
World Health Organization, 1989. Wastewater utilization in agriculture and aquaculture: sanitary recommendations. Technical Report no. 778, Geneva: 82 pp.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Merlin, G., Pajean, JL. & Lissolo, T. Performances of constructed wetlands for municipal wastewater treatment in rural mountainous area. Hydrobiologia 469, 87–98 (2002). https://doi.org/10.1023/A:1015567325463
Issue Date:
DOI: https://doi.org/10.1023/A:1015567325463