Plant ability for tolerating and accumulating high amount of heavy metal is used as a promissory technology for removing contaminants from highly polluted environments. The ability of the macrophyte L. aequinoctialis to remove heavy metal was studied in two different sampling times during its flowering. Samples of plant tissue L. aequinoctialis and water were collected for 800 hours at 48 hour intervals. Concentrations of Ni, Cu, Co, Cr, Mn, Zn, and Fe present in L. aequinoctialis and water were determined by flame atomic absorption spectrometry (FAAS). Data were subjected to the techniques of principal components analysis (PCA), hierarchical cluster analysis (HCA) and boxplot. We found that rhizofiltration of L. aequinoctialis removes high amount of heavy metal in this order: Cr >Ni>Cu> Fe > Zn >Mn. Only significant changes in chemical composition of the water, pH and electrical conductivity alter the absorption capacity of L. aequinoctialis. | A capacidade das plantas em tolerar e absorver quantidades elevadas de metais pesados é usada como uma tecnologia promissora para limpeza de resíduos perigosos em ambientes altamente contaminados. O desempenho da macrófita L. aequinoctialis em absorver metais pesados foi estudado durante sua floração em dois períodos de amostragem diferentes. As amostras de L. aequinoctialis e água foram coletadas por 800 horas em intervalos de 48 horas. A quantidade de Ni, Cu, Co, Cr, Mn, Zn e Fe presente na L. aequinoctialis e água foram determinados por espectrometria de absorção atômica com chama (FAAS). Os resultados foram avaliados pelas técnicas de estatística de componentes principais (PCA), análise de agrupamento hierárquico (HCA) e boxplot. Os resultados mostram que a rizofiltração da L. aequinoctialis remove altas quantidades de metais pesados na seguinte ordem Cr > Ni > Cu > Fe > Zn > Mn. No entanto, observou-se que mudanças significativas na composição química, pH e condutividade elétrica da água alteram a capacidade de absorção da L. aequinoctialis.

In January 2003, in the Animal Production Research Unit, Lara, Venezuela, duckweed ( Lemna minor ) was cultured in microlagoons to determine biomasa production. Three experiments (E) were carried out with a totally randomized design: E1 (T0 = 30 g of duckweed, T1 = 30 g of duckweed and 32 g of fertilizer), E2 (T0 = 5 g of duckweed, T1 = 5 g of duckweed and 32 g of fertilizer), with 25 repetitions per treatments; and E3 (T0 = 5 g of duckweed, T1 = 5 g of duckweed and 20 g of fertilizer, T2 = 5 g of duckweed and 30 g of fertilizer, and T3 = 5 g of duckweed and 40 g of fertilizer), with 15 repetitions per treatment. The duckweed gave higher yieldeds when fertilized, and the yields depended of the quantities of vegetative material and fertilizer added to the microlagoon. | En enero de 2003, en la Unidad de Investigación en Producción Animal, Lara, Venezuela, la lenteja de agua ( Lemna minor ) fue cultivada en microlagunas para determinar su producción de biomasa. Se realizaron tres experimentos (E) con diseños completamente aleatorizados, a saber: E1 (T0= 30 g de lenteja de agua, T1= 30 g de lenteja de agua y 32 g de fertilizante); E2 (T0= 5 g de lenteja de agua, T1= 5 g de lenteja de agua y 32 g de fertilizante), con 25 repeticiones por tratamiento; y E3 (T0= 5 g de lenteja de agua, T1= 5 g de lenteja de agua y 20 g de fertilizante, T2= 5 g de lenteja de agua y 30 g de fertilizante, y T3= 5 g de lenteja de agua y 40 g de fertilizante), con 15 repeticiones por tratamiento. La Lemna minor presentó una mayor producción de biomasa al ser fertilizada, y el rendimiento fue dependiente de las cantidades de material vegetativo y fertilizante que se adicionaron en la microlaguna.

Se ha verificado que la especie invasora lenteja de agua ocupa la mayoría de los espejos de aguas tranquilas en la Bogotá-Región y ha generado repercusiones negativas para los ecosistemas cambiando las dinámicas de las especies. El manejo actual de remover manual o mecánicamente la planta es técnica y económicamente difícil dada la capacidad de la especie de replicarse rápidamente. El presente proyecto de investigación busca aprovechar esa capacidad de replicación para la identificación y caracterización de alternativas de economía circular que permitan el aprovechamiento eficiente de la planta. El trabajo se desarrolló en tres fases, la primera encaminada a validar la problemática en la región, la segunda priorizó las alternativas de aprovechamiento a través de un análisis multicriterio y la tercera desarrolló pruebas de laboratorio para corroborar la factibilidad de las alternativas de aprovechamiento priorizadas en la fase dos. Las alternativas mejor calificadas corresponden al compostaje, bioetanol y biodiesel respectivamente, para las cuales, la producción de bioetanol presentó los mejores resultados en laboratorio. | Ingeniero Ambiental | Pregrado | The aquatic invasive species duckweed reported in the majority of calm water mirrors in the Bogotá-Region has generated effects for the ecosystems, changing the dynamics of the species and habitats, and for the economy in general, since its control is economically unsustainable. The purpose of this research project was to identify and characterize circular economy alternatives for the efficient use of the invasive duckweed species, reducing its environmental impact on the water bodies of Bogotá-Region. During the development of the dimensioning phase, bibliographic references were consulted on studies carried out at the regional, national and international level on the problems faced by the invasive species and the alternative uses that could revolve around it. Once the current situation of duckweed was contextualized, the Multicriteria Analysis methodology was extracted, where different criteria concerning the ecological and economic dimensions of the previously consulted utilization alternatives were evaluated qualitatively and quantitatively; Thus, prioritizing the most viable alternatives will be modified for their subsequent controlled performance in the laboratory. For the composting alternative, there was a time of 21 days, 1.5 kg of duckweed was obtained and the need to complement this procedure with other organic waste and/or insects such as: earthworms or slugs to increase its efficiency was verified. ; on the other hand, the biodiesel generation alternative arises from low efficiency with a product of 11,456 ml from the extraction of the essential oil of 30 ml of duckweed and 7 ml of methoxide; Finally, the bioethanol generation alternative showed great efficiency in the distillation procedure with a 48 ml product from 100 ml of fermented duckweed solution.