This work has examined the effects of pH on the treatment efficiency and biomass production rate of water hyacinth ponds (WHP) treating domestic wastewater. Experiments were carried out outdoor in WHP, working under batch and subtropical environmental conditions, using pre-treated sewage with pH varying from 5 to 9. It was observed that the plants regulated the pH of the medium to within 6.4 to 7.1 during the treatment processes independently of influent wastewater pH ranges. This adjustment reduced the treatment performances and the biomass production in ponds, the alkaline conditions in ponds being less favorable to the activities of the plants. The optimal removal and biomass production was achieved with influent pH of 7 lying in the above interval. So the optimum influent pH for the growth of plants and the removal of nutrients and organic matters in WHP is within pH 6.4 to pH 7.1.
Center, T., Hill, M., Cordo, H. and Julien, M. (2002) Waterhyacinth. In: Van Driesche, R., et al., Eds., Biological Control of Invasive Plants in the Eastern United States, United States Forest Service, Washington DC, 41-64.
Gopal, B. (1987) Water hyacinth. Elsevier Science Publishers, Amsterdam.
Coetzee, J., Hill, M., Julien, M., Center, T. and Cordo, H. (2009) Eichhornia crassipes (Mart.) Solms-Laub. (Pontederiaceae). In: Muniappan, R., Reddy, G.V.P. and Raman, A., Eds., Biological Control of Tropical Weeds using Arthropods, Cambridge University Press, New York, 183-210. https://doi.org/10.1017/CBO9780511576348.011
Malik, A. (2007) Environmental Challenge vis a vis Opportunity: The Case of Water Hyacinth. Environment International, 33, 122-138. https://doi.org/10.1016/j.envint.2006.08.004
Nesic, N. and Jovanovic, L. (2010) Potential Use of Water Hyacinth (E. crassipens) for Wastewater Treatment in Serbia.
Singhal, V. and Rai, J.P.N. (2003) Biogas Production from Water Hyacinth and Channel Grass Used for Phytoremediation of Industrial Effluents. Bioresource Technology, 86, 221-225. https://doi.org/10.1016/s0960-8524(02)00178-5
Wang, Z., Zhang, Z., Zhang, J., Zhang, Y., Liu, H. and Yan, S. (2012) Large-Scale Utilization of Water Hyacinth for Nutrient Removal in Lake Dianchi in China: The Effects on the Water Quality, Macrozoobenthos and Zooplankton. Chemosphere, 89, 1255-1261. https://doi.org/10.1016/j.chemosphere.2012.08.001
Polprasert, C., Kessomboon, S. and Kanjanaprapin, W. (1992) Pig Wastewater Treatment in Water Hyacinth Ponds. Water Science & Technology, 26, 2381-2384.
Chunkao, K., Nimpee, C. and Duangmal, K. (2012) The King’s Initiatives Using Water Hyacinth to Remove Heavy Metals and Plant Nutrients from Wastewater through Bueng Makkasan in Bangkok, Thailand. Ecological Engineering, 39, 40-52. https://doi.org/10.1016/j.ecoleng.2011.09.006
McLay, C. (1976) The Effect of pH on the Population Growth of Three Species of Duckweed: Spirodela oligorrhiza, Lemna minor and Wolffia arrhiza. Freshwater Biology, 6, 125-136. https://doi.org/10.1111/j.1365-2427.1976.tb01596.x
Bisson, M., Gay, G., Guillard, D., Ghillebaert, F. and Tack, K. (2009) Sélénium et ses composés. I NERIS-Fiche de données toxicologiques et environnementales des substances chimiques.
Pichard, A., Bisson, M., Houeix, N., Gay, G., Lacroix, G., Lefevre, J., Magaud, H., Migne, V., Morin, A. and Tissot, S. (2005) Fiche de données toxicologiques et environnementales des substances chimiques: Cuivre & ses dérivés. Institut national de l'environnement industriel et des risques, Verneuil-en-Halatte.
Téllez, T.R., López, E., Granado, G.L., Pérez, E.A., López, R.M. and Guzmán, J.M.S. (2008) The Water Hyacinth, Eichhornia crassipes: An Invasive Plant in the Guadiana River Basin (Spain). Aquatic Invasions, 3, 42-53.
Allgayer, R. (2006) Plantes d'aquarium. Editions Artemis, Chamalières.
Azov, Y. and Goldman, J.C. (1982) Free Ammonia Inhibition of Algal Photosynthesis in Intensive Cultures. Applied and Environmental Microbiology, 43, 735-739.
ASCECNA (2008) Données pluviométriques de Cotonou: Station de l’Aéroport de Cotonou. L’Agence pour la Sécurité de la Navigation aérienne en Afrique et à Madagascar, Dakar.
Hounkpè, S.P., Adjovi, E.C., Crapper, M. and Awuah, E. (2014) Wastewater Management in Third World Cities: Case Study of Cotonou, Benin. Journal of Environmental Protection, 5, 387-399. http://doi.org/10.4236/jep.2014.55042
Soltan, M.E. and Rashed, M.N. (2003) Laboratory Study on the Survival of Water Hyacinth under Several Conditions of Heavy Metal Concentrations. Advances in Environmental Research, 7, 321-334.
Akcin, G., Saltabas, O. and Afsar, H. (1994) Removal of Lead by Water Hyacinth (Eichhornia crassipes). Journal of Environmental Science & Health Part A, 29, 2177-2183. https://doi.org/10.1080/10934529409376172
Awuah, E. (2006) Pathogen Removal Mechanisms in Macrophyte and Algal Waste Stabilization Ponds. Institute for Water Education, Wageningen University and Academic Board of the UNESCO-IHE, Wageningen, 147.
Ashby, E. and Oxley, T. (1935) The Interaction of Factors in the Growth of Lemna VI. An Analysis of the Influence of Light Intensity and Temperature on the Assimilation Rate and the Rate of Frond Multiplication. Annals of Botany, No. 2, 309-336.
Al-Nozaily, F.A. (2001) Performance and Process Analysis of Duckweed-Covered Sewage Lagoons for High Strength Sewage: The Case of Sana’a, Yemen. International Institute for Infrastructural, Hydraulic and Environmental Engineering, Delft University of Technology, Delft, 248.
Hounkpè, S.P., Adjovi, E.C., Crapper, M. and Aina, M.P. (2013) Mise au point d'un système intégré de gestion des eaux uses. Revue Ivoirienne des Sciences et Technologies, No. 21&22, 154-173.
Balasooriya, I., Paulraj, P., Abeygunawardena, S. and Nanayakkara, C. (1984) Biology of Water Hyacinth: Physico Chemical Properties of the Water Supporting Eichhornia crassipes (Mart.) Solms. Proceedings of the International Conference on Water Hyacinth, Hyderabad, 7-11 February, 1983.
del Mar Delgado, M., Bigeriego, M., Walter, I. and Guardiola, E. (1994) Optimization of Conditions for the Growth of Water Hyacinth in Biological Treatment. Revista internacional de contaminacion ambiental, 10, 63-68.
Kim, Y. and Kim, W.-J. (2000) Roles of Water Hyacinths and Their Roots for Reducing Algal Concentration in the Effluent from Waste Stabilization Ponds. Water Research, 34, 3285-3294. https://doi.org/10.1016/S0043-1354(00)00068-3
Henze, M., Harremoes, P., la Cour Jansen, J. and Arvin, E. (2001) Wastewater Treatment: Biological and Chemical Processes. Springer, Berlin, Heidelberg.
Pearson, H., Mara, D., Mills, S. and Smallman, D. (1987) Physico-Chemical Parameters Influencing Faecal Bacterial Survival in Waste Stabilization Ponds. Water Science & Technology, 19, 145-152. https://doi.org/10.2166/wst.1987.0139
Caicedo Bejarano, J.R. (2005) Effect of operational variables on nitrogen transformations in duckweed stabilization ponds. The UNESCO-IHE Institute for Water Education, Delf, 163.
Maharjan, R.B.S. and Ming, C.L. (2012) The Potential Role of Water Hyacinth in Wastewater Treatment in Nepal. Hydro Nepal: Journal of Water, Energy and Environment, 10, 36-41. https://doi.org/10.3126/hn.v10i0.7101
Gibbs, R.A., Hu, C.J., Ho, G.E. and Unkovich, I. (1997) Regrowth of Faecal coliforms and Salmonellae in Stored Biosolids and Soil Amended with Biosolids. Water Science and Technology, 35, 269-275. https://doi.org/10.2166/wst.1997.0745
Gersberg, R.M. and Silvaggio, D.A. (1992) Fate of Coliphage during Wastewater Treatment by Water Hyacinth (Eichhornia crassipes). Ecological Engineering, 1, 355-363. https://doi.org/10.1016/0925-8574(92)90015-t
Awuah, E., Oppong-Peprah, M., Lubberding, H.J. and Gijzen, H.J. (2004) Comparative Performance Studies of Water Lettuce, Duckweed, and Algal-Based Stabilization Ponds Using Low-Strength Sewage. Journal of Toxicology and Environmental Health, Part A, 67, 1727-1739. https://doi.org/10.1080/15287390490493466
Van der Steen, P., Brenner, A., Shabtai, Y. and Oron, G. (2000) The Effect of Environmental Conditions on Faecal coliform Decay in Post-Treatment of UASB Reactor Effluent. Water Science & Technology, 42, 111-118. https://doi.org/10.2166/wst.2000.0621
Liltved, H. and Landfald, B. (2000) Effects of High Intensity Light on Ultraviolet-Irradiated and Non-Irradiated Fish Pathogenic Bacteria. Water Research, 34, 481-486. https://doi.org/10.1016/S0043-1354(99)00159-1