Author(s)

M. C. Jiménez-Moleón, M. T. Mota-González & J. A. Ascencio-Gutiérrez

Abstract

Metal presence is a serious pollution problem in natural or treated water. The water hyacinth (Eichhornia crassipes) is an aquatic plant known for its high capacity to absorb metals. However, to use water hyacinths in a sustainable pollution removal process, the parameters that affect the process of metal absorption and the disposal of the contaminated organic matter must be studied; these being the aims of this work. Water hyacinth assays were carried out in distilled water and the influence of Mn2+ initial concentrations (Co: 10, 50, 100mg/L) and initial pH (pHo: 3, 5, 7) were analyzed. Parameters such as pH, electric conductivity (EC), and residual Mn2+ were also measured. At the end of every assay, Mn was quantified in the different sections of the water hyacinth (root \“R”, petiole \“P” and leaf \“L”) by atomic absorption spectrometry, and the presence of metal aggregates was detected by TEM microscopy. E. crassipes did not neutralize its growing medium. The EC was not a good control parameter for absorption, increased with time. The water hyacinth was capable of efficiently removing Mn2+ from the solutions. It can be seen two phases of absorption (a rapid one followed by a slow absorption phase nearly linear). With increasing Co, the absorbed Mn2+ increased, but the percentage of absorption during the rapid phase diminished. The final percentage of absorption increased with pHo independently of Co. The water hyacinth is capable of effectively translocating Mn. The bioconcentration factor (BCF) diminished with Co, and increased with pHo.

Keywords

absorption, bioconcentration factor, E. crassipes, initial concentration, initial pH, Mn, nanotechnology, translocation, water hyacinth