Eficiencia de tres sistemas de humedales híbridos para la remoción de carbamazepina

En general, se ha encontrado que los humedales construidos son efectivos en diferentes grados para la remoción de fármacos; sin embargo, existen casos como el de la carbamazepina (CBZ), cuyas eficiencias de remoción reportadas han sido muy bajas. El objetivo de este estudio fue evaluar las eficiencias de remoción másica de dicho fármaco en tres sistemas de humedales híbridos con dos etapas de tratamiento, incluyendo humedales subsuperficiales de flujo horizontal (HSSFH), humedales subsuperficiales de flujo vertical (HSSFV) y lagunas de estabilización (LE). Las tres diferentes configuraciones fueron HSSFH-LE, HSSFHHSSFV y HSSFV-HSSFH, denominados como SI, SII y SIII, respectivamente. Además, se realizaron mediciones in situ de OD, Eh, pH, CE, ET y temperatura, con el propósito de conocer en qué condiciones operaban dichos sistemas. Los resultados revelaron diferencias significativas (p < 0.05) en la eficiencias de remoción de los sistemas híbridos, con un promedio de 60 ± 4.45% para SI, 55 ± 4.45% para S II y 36 ± 4.45% para SIII, siendo SI y SII estadísticamente iguales y ambos diferentes a SIII. En general, las mayores eficiencias se presentaron en los sistemas con concentraciones bajas OD, valores negativos de Eh y condiciones de pH cercanas a ocho, que se tienen principalmente en los humedales subsuperficiales de flujo horizontal. En contraste, condiciones aerobias de operación demostraron ser menos eficientes. Dichos resultados corroboran la capacidad de los humedales construidos para remover carbamazepina y demuestran que es posible incrementar su remoción mediante la combinación adecuada de diferentes tipos de humedales

Propagación in vitro de Hylocereus purpusii Britton Rose, una especie mexicana en peligro de extinción

The purpose ofthis workwasto evalúate different conditions and culture parametersforthein vitro establishment and multiplicaron of Hylocereus purpusii. Seeds were used as plant material and a workflowwas developed as an alternative forthe propagation and recovery ofthis species in danger of extinction. ln the establishment phase, the best result was obtained in the treatment with 1% NaOCI for 15 minutes achieving a 90% of germinated seeds and a final 77.7% of in vitro established plants. ln the multiplicaron phase when combining 8.88 uM 6-BAP with different concentrations of IAA, a significant increment in the length of the shoots was observedwith respecttothe control (no addition of IAA). Acombination of8.88 uM 6-BAP with 3.42 uM IAA was selected as the best multiplication condition reaching a multiplicaron rate of 8.8. ln the acclimatization phase, after two months of culture in ex vitro conditions the survival was higher than 98% and after six months of growth, the plants were transplanted to field.Key words: cactus; disinfection; growth regulators; seed germinationEl propósito de este trabajo fue evaluar diferentes condiciones y parámetros de cultivo para el establecimiento in vitro y multiplicación de Hylocereus purpusii. El protocolo de trabajo se desarrolló como una alternativa para la propagación y la recuperación de esta especie en peligro de extinción. Se utilizaron semillas como material vegetal inicial. En la fase de establecimiento, el mejor resultado se obtuvo en el tratamiento con hipoclorito de sodio al 1% durante 15 minutos. Se logró un 90% de semillas germinadas y finalmente un 77.7% de plantas establecidas in vitro. En la fase de multiplicación cuando se combinaron 8.88 uM de 6-BAP con diferentes concentraciones de AIA, se observó un incremento significativo en la longitud de los brotes con respecto al control (sin adición de AIA) La combinación de 8 88 uM de 6-BAP con 3 42 uM de AlAfue seleccionada como la mejor para la fase de multiplicación y para alcanzar un coeficiente de 88. En la fase de aclimatización tras dos meses de cultivo en condiciones ex vitro, la supervivencia fue superior al 98%. Después de seis meses de crecimiento, las plantas fueron transplantadas a campo.Palabras clave: cactus, desinfección, reguladores del crecimient

Capacity of Two Ornamental Species (Iris sibirica and Zantedeschia aethiopica) to Take up, Translocate, and Accumulate Carbamazepine under Hydroponic Conditions

Iris sibirica and Zantedeschia aethiopica are ornamental species that have previously been used in pilot-scale treatment wetlands (TWs) focused on the removal of carbamazepine (CBZ), in which good results were obtained; however, the plant influence was not completely determined. In addition, plant uptake has been reported to play a crucial role in CBZ removal in comparison to other mechanisms. Therefore, the aim of this study was to evaluate the capacity of I. sibirica and Z. aethiopica to take up, translocate, and accumulate CBZ in hydroponic conditions using a nutrient solution spiked with the drug. The maximum CBZ tolerance threshold for the two species was found to be 10 mg/L, which was used to carry out the uptake experiments. The results showed a better performance of I. sibirica compared to Z. aethiopica reaching 31.1% and 20.9% of removal efficiency, respectively. The parent compound accumulated mainly on the leaves of both species. Furthermore, a high proportion of the CBZ taken up by the plants (up to 70%) was metabolized by both species. The performance of the two species suggests the importance of plant harvesting in TWs in order to promote CBZ removal and indicates the need for future works

Adsorption Capacity of a Volcanic Rock—Used in ConstructedWetlands—For Carbamazepine Removal, and Its Modification with Biofilm Growth

In this study, the aim was to evaluate the adsorption capacity of a volcanic rock commonly used in Mexico as filter medium in constructed wetlands (locally named tezontle) for carbamazepine (CBZ) adsorption, as well as to analyze the change in its capacity with biofilm growth. Adsorption essays were carried out under batch conditions by evaluating two particle sizes of tezontle, two values of the solution pH, and two temperatures; from these essays, optimal conditions for carbamazepine adsorption were obtained. The optimal conditions (pH 8, 25 °C and 0.85–2.0 mm particle-size) were used to evaluate the adsorption capacity of tezontle with biofilm, which was promoted through tezontle exposition to wastewater in glass columns, for six months. The maximum adsorption capacity of clean tezontle was 3.48 µg/g; while for the tezontle with biofilm, the minimum value was 1.75 µg/g (after the second week) and the maximum, was 3.3 µg/g (after six months) with a clear tendency of increasing over time. The adsorption kinetic was fitted to a pseudo-second model for both tezontle without biofilm and with biofilm, thus indicating a chemisorption process. On clean tezontle, both acid active sites (AAS) and basic active sites (BAS) were found in 0.087 and 0.147 meq/g, respectively. The increase in the adsorption capacity of tezontle with biofilm, along the time was correlated with a higher concentration of BAS, presumably from a greater development of biofilm. The presence of biofilm onto tezontle surface was confirmed through FTIR and FE-SEM. These results confirm the essential role of filter media for pharmaceutical removal in constructed wetlands (CWs)

Treatment of tequila vinasse mixed with domestic wastewater in two types of constructed wetlands

Tequila vinasse (TV) is a high-strength effluent generated during the production of tequila, with a chemical oxygen demand (COD) concentration of up to 74 g/L. In this study, the treatment of TV was evaluated in a 27-week study in two types of constructed wetlands (CWs), namely horizontal subsurface flow wetlands (HSSFWs) and vertical upflow wetlands (VUFWs). The pre-settled and neutralized TV was diluted at 10, 20, 30, and 40% with domestic wastewater (DWW). Volcanic rock (tezontle) was used as the substrate and Arundo donax and Iris sibirica as emergent vegetation. The two systems showed similar high removal efficiencies for COD, biochemical oxygen demand (BOD5), turbidity, total suspended solids (TSS), true colour (TC), electrical conductivity (EC), and total nitrogen (TN). The highest average percentages of removal were obtained at 40% of dilution: 95.4 and 95.8% for COD, 98.1 and 98.2% for turbidity, 91.8 and 95.9% for TSS, and 86.5 and 86.4% for TC in the HSSFWs and the VUFWs, respectively. This study demonstrates the potential of CWs for TV treatment as a major step in a treatment system. HIGHLIGHTS Tequila vinasse is a high-strength effluent.; Tequila vinasses remain untreated in micro and small factories.; TV can be mixed with domestic wastewater to reduce pollutant concentrations.; Constructed wetlands can be designed for the treatment of TV mixed with DWW.; HSSFWs and VUFWs are efficient for the treatment of TV + DWW.

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

Generation of Tequila Vinasses, Characterization, Current Disposal Practices and Study Cases of Disposal Methods

Tequila vinasse is a liquid waste generated during the production of tequila, an emblematic alcoholic beverage in Mexico. The objective of this study was to carry out an investigation on the tequila factories located in the state of Jalisco in order to know the location of the factories in the state, the characterization of the vinasses including factories of different sizes, the current treatment methods, and disposal practices as well as the impacts of common practices of vinasse disposal. Part of the information was collected by applying a questionnaire to the tequila factories previously contacted (and physically located). For the vinasse characterization, 24 tequila factories provided a composite sample of vinasse. To assess the impact of common vinasse disposal practices, a stream running through tequila factories, soil that has been used for vinasse discharge for 14 years, and a well located near the soil were evaluated. In two main regions (Valle and Altos Sur), 110 tequila factories distributed in 10 municipalities, were identified. Vinasse disposal and treatment problems are mainly related to micro-factories that do not treat their vinasse at all. The most common method of disposal is discharging on soils. Only in the Valle region is disposal in surface waters a common practice, as well as discharges into sewage systems. The monitored stream is totally degraded with low pH, high concentrations of organic matter, suspended solids, etc. Soil fertility has not been affected due to a method of vinasse discharge-soil rest. The texture of the soils (high content of clay and silt) has been decisive in protecting groundwater from the infiltration of vinasse. The results obtained in this study could help the authorities to develop adequate strategies for the management of vinasses (treatment and disposal), mainly in micro and small tequila factories