El tratamiento de las aguas residuales municipales en las comunidades rurales de México

Recently, efforts have been made to increase municipal wastewater treatment plants in Mexico; however, efforts have focused mainly on urban communities. Municipal wastewater can be treated with different technologies ranging from expensive and highly mechanized equipment to relatively simple and low-cost ecological treatment systems. This paper's aim is to research the current status of municipal wastewater treatment in Mexican rural communities, discussing the main barriers and challenges to overcome in order to increase coverage of treatment plants in these communities. In most states, municipal wastewater treatment plants coverage in small rural communities, with less than 2 500 inhabitants have not been taken care of, especially those 47 233 villages with populations ranging from 100 to 2 499 inhabitants, where it is feasible to install treatment plants. In rural areas, the priority has been given to drinking water supply and sewage, increasing the volumes of wastewater collected. The treatment systems that are most commonly used for the small rural communities with municipal wastewater treatment plants are stabilization ponds and constructed wetlands, followed by sedimentation or septic tanks. Stabilization ponds are quite common in Mexico, whereas constructed wetlands have faced dome barriers preventing their implementationon a larger scale. Some of these obstacles are, deficient knowledge about this technology, lack of basic, easily designed manuals for potential users, etcRecientemente se han hecho esfuerzos, por incrementar la cobertura de plantas de tratamiento de aguas residuales municipales en México; sin embargo, estos esfuerzos se han enfocado principalmente en las comunidades urbanas. Para el tratamiento de aguas residuales municipales, existen diversas tecnologías que van desde las altamente mecanizadas y costosas, hasta las tecnologías relativamente simples y de bajo costo. El objetivo de este trabajo, es investigar el estado actual del tratamiento de las aguas residuales municipales en las comunidades rurales en México, así como discutir cuáles son las barreras y retos que se deben superar, para incrementar la cobertura de plantas de tratamiento. En la mayoría de los estados, se está dejando de atender las pequeñas comunidades rurales de menos de 2 500 habitantes, en especial aquellas 47 233 localidades con 100-2 499 habitantes, en donde es factible instalar plantas de tratamiento. En las zonas rurales se ha dado prioridad a la cobertura de agua potable y los servicios de alcantarillado, lo que ha incrementado el volumen de aguas residuales municipales. Los sistemas de tratamiento que más se emplean en las comunidades rurales, que cuentan con plantas de tratamiento de aguas residuales municipales, son las lagunas de estabilización y los humedales artificiales precedidos de sedimentación o fosa séptica. Mientras que las lagunas de estabilización son bastante comunes en México, los humedales artificiales enfrentan algunas barreras, que han evitado su implementación en forma masiva; por el poco conocimiento de esta tecnología y la falta de diseños accesibles a los usuarios directos

Regeneración de Sedum praealtum A.DC (siempreviva) vía organogénesis

La siempreviva (Sedum praealtum A.DC) pertenece a la familia Crassulaceae, desde hace mucho tiempo ha sido utilizada en la etnobotánica mexicana como un agente anti-inflamatorio y analgésico, en el tratamiento de dolor de dientes, amigdalitis, para enfermedades de los ojos, erupciones cutáneas y de regeneración de tejidos, recientemente se le descubrieron compuestos con actividad antioxidante que presentan efectos hepatoprotector y anticancerígeno. Se estableció un protocolo eficiente de regeneración mediante organogénesis para Sedum praealtum a partir de hojas jóvenes de plantas provenientes de vivero. Fragmentos de hoja que contenían la parte media se cultivaron en medio Murashige y Skoog adicionado con bencilaminopurina (6-BAP) y 2,4-Diclorofenoxiacético (2,4-D) en varias combinaciones. A los 90 días de haber iniciado el cultivo, el tratamiento suplementado con 0.5 mg/L de 6-BAP, 0.0 mg/L de 2,4-D mostró efectos significativos sobre el desarrollo de órganos por la vía indirecta, dando en promedio 13.0±0.3 brotes por explante. Los brotes se individualizaron y se transfirieron a medio MS suplementado con 2.0 mg/L de ácido indolacético (AIA) para su enraizamiento.Siempreviva (Sedum praealtum A. DC) belongs to the Crassulaceae family, it has long been used in Mexican ethnobotanical as an anti-inflammatory and analgesic agent in the treatment of toothache, tonsillitis, for eyes diseases, sking and tisuue regeneration eruption, was recently discovered antioxidant compounds havings hepatoprotective and anticancer effects. An efficient protocol for organogenesis regeneration was established for Sedum praealtum from young leaves of nursery plants. Leaf segment that contained the middle portion of the leaf were cultured on Murashige and Skoog medium supplemented with different combintions of 6-Benzylaminopurine (6-BAP) and 2,4-Dichlorophenoxyacetic acid (2,4-D). 90 days after culture, the highest shoot induction was observed on MS medium supplemented with 0.5 mg/L 6-BAP and 0.0 mg/L 2,4-D with 13.0±0.3 shoot per explant. Shoot were individualized and transferred to MS médium supplemented with 2.0 mg/L Indoleacetic acid (IAA) for rooting

Regeneración de Sedum praealtum A.DC (siempreviva) vía organogénesis

Introduction: Dalbergia congestiflora Pittier (campincerán) is used to make musical instruments in Michoacán (Mexico), so this specie is considered overexploited and at risk of extinction. Propagation studies of campincerán are scarce, but the factors that could affect the propagation by stem cuttings of this species are auxin exogenous concentration and position of the stem cuttings (apical, media and basal). The hypothesis tested is that a higher sprouting and rooting at concentrations between 1 and 10 ppm of indolbutyric acid (IBA) and the basal stem cuttings are observed. Method: The stem cuttings of D. congestiflora were collected in Tacámbaro, Michoacán. The apical, middle and basal cuttings were placed in a rooting solution of 1, 5 and 10 ppm of IBA. The variables studied were the sprouting percentage, the mean number of sprouts and the mean length of the sprouts after 15, 45 and 75 days, while the percentage of rooting was evaluated after 150 days. Results: The sprouting percentage, mean number of sprouts and mean length of sprouts were higher in basal cuttings in relation to the apical and meddle cuttings. The rooting was observed only at basal cuttings with 10 ppm of IBA. Conclusion: The sprouting of cuttings was observed at low cocentrations of IBA and this is independent of position stem cuttings, but the rooting occurred only at 10 ppm of IBA