El agua regenerada y la producción de biocombustibles

[ES] La Jatropha curcas L., una especie tóxica que no interfiere en la cadena alimentaria, produce biodiesel de mejor calidad ambiental que los aceites de origen mineral pero, para su cultivo, se emplean recursos limitados, fundamentalmente agua y suelo. Por tanto, en las zonas áridas es necesario cultivarla en condiciones intensivas, regando con aguas regeneradas y disminuyendo los costes productivos. Para optimizar el consumo del agua se ha empleado el riego alterno de raíces, que mantiene seca una parte del sistema obteniéndose menos frutos/racimo pero más racimos fértiles/árbol, lo que permitirá estrechar el marco de plantación, una de las pocas opciones para mejorar su rentabilidad pues la producción por árbol es muy estable

Microextraction techniques coupled to liquid chromatography with mass spectrometry for the determination of organic micropollutants in environmental water samples

[EN]Until recently, sample preparation was carried out using traditional techniques, such as liquid–liquid extraction (LLE), that use large volumes of organic solvents. Solid-phase extraction (SPE) uses much less solvent than LLE, although the volume can still be significant. These preparation methods are expensive, time-consuming and environmentally unfriendly. Recently, a great effort has been made to develop new analytical methodologies able to perform direct analyses using miniaturised equipment, thereby achieving high enrichment factors, minimising solvent consumption and reducing waste. These microextraction techniques improve the performance during sample preparation, particularly in complex water environmental samples, such as wastewaters, surface and ground waters, tap waters, sea and river waters. Liquid chromatography coupled to tandem mass spectrometry (LC/MS/MS) and time-of-flight mass spectrometric (TOF/MS) techniques can be used when analysing a broad range of organic micropollutants. Before separating and detecting these compounds in environmental samples, the target analytes must be extracted and pre-concentrated to make them detectable. In this work, we review the most recent applications of microextraction preparation techniques in different water environmental matrices to determine organic micropollutants: solid-phase microextraction SPME, in-tube solid-phase microextraction (IT-SPME), stir bar sorptive extraction (SBSE) and liquid-phase microextraction (LPME). Several groups of compounds are considered organic micropollutants because these are being released continuously into the environment. Many of these compounds are considered emerging contaminants. These analytes are generally compounds that are not covered by the existing regulations and are now detected more frequently in different environmental compartments. Pharmaceuticals, surfactants, personal care products and other chemicals are considered micropollutants. These compounds must be monitored because, although they are detected in low concentrations, they might be harmful toward ecosystems.