Evaluación de vetiver (Chrysopogon zizanioides) y la elefanta (Pennisetum purpureum) en el diseño de humedales artificiales

Abstract

In this thesis is presented the description and research in the evaluation of vetiver (Chrysopogon zizanioides) and the elephant (Pennisetum purpureum) in the design of artificial wetlands. For the treatment of wastewater from households, vegetation being one of the main components of these systems unconventional treatments. \ Many natural systems " are being considered for the purpose of wastewater treatment and control of water pollution due to its high reliability and low environmental costs of construction and maintenance, in the case of artificial wetlands. The interest in natural systems is based on the conservation of the resources associated with these systems as opposed to conventional treatment process wastewater it is intensive regarding the use of energy and chemicals. Wetlands or artificial wetlands is an alternative treatment because of its high efficiency of removal of contaminants, its low cost of installation and maintenance and its high environmental reliability, usually an artificial wetland is constituted by a support means which is usually sand or gravel, vegetation and microorganisms or biofilm which carry different biochemical processes to remove contaminants from the effluent. The overall objective of this study is evaluate the efficiency of removal of contaminants and / or organic compounds of two species of plants: vetiver (Chrysopogon zizanioides) and the elephant (Pennisetum purpureum), the design Artificial for treating wastewater from households wetlands. Constructed wetlands systems or drivers, are located at the University of Medellin and receive a synthetic preparation of water, which resembles the characteristics of waste water from households. In this paper the percentage of removal of the organic load of wastewater in a treatment system for constructed wetlands with two plant species evaluated. The system was designed with three modules installed sequentially. Organisms in the second organisms of the species vetiver (Chrysopogon zizanioides) were integrated in the third pilot system - the first was not any plant species integrates only the middle of substrate which is white (-) the (Pennisetum purpureum) elephant species and the fourth agencies Japanese papyrus species (Cyperus alternifolius), which constitute the white (+). The experimental modules were cleaned, cut and appropriate according to the initial assembly plant and the space required for disposal. Each pilot system is added support means consisting of gravel (5 to 10 cm) and sand (15 to 20 cm), each substrate is assessed and characterized by their nominal diameter, back in each system species are planted in an area of 3x3 and each wetland for two weeks it ts under Hoagland and Arnon solution and moisture regime. In the synthetic water the following parameters were analyzed: pH, total solids, total suspended solids, total dissolved solids, chemical oxygen demand (COD), biochemical oxygen demand (DBO5), total nitrogen (TKN) and total phosphorus ( PT). Determining the growth of plants it was also performed from the increased biomass root porosity and similarly NTK and PT is determined. The results showed that the system is an option to remove the organic matter and nutrients in wastewater from households, low cost of operation and maintenance, especially is observed that plants growing in systems aquic moisture regime and ustic tend to have greater reception and adaptation in artificial wetlands pilots, the case of the elephant (Pennisetum purpureum), which has the highest rates of rmeoci on of pollutants and nutrients in the effluent, followed by the Japanese papyrus (Cyperus alternifolius) and vetiver (Chrysopogon zizanioides) regarding removal rates. The removal of contaminants present higher respectively, are solid at first, followed by biochemical oxygen demand (DBO5), chemical oxygen demand (COD), total nitrogen (TKN) and total phosphorus (TP) the latter have a low removal rate due to the nature of the contaminant the bodies carrying out the removal and absorption and retention time is chosen, which influences the pollutant removal rate being lower in concentration phosphorus, but are in the range expected for these systems unconventional treatment.