Analysis of drug of abuse compounds using passive sampling and ultrahigh-liquid chromatography coupled to mass spectrometry.

The present study proposes the monitoring of compounds of drugs of abuse through the use of passive samplers in water systems. Initially, four positive ion compounds of interest were determined according to national surveys, and then composite sampling and passive sampling were implemented using continuous-flow passive samplers containing two types of sorbents, the Empore disk and Gerstel Twister. Two study sites were established at the beginning and at the end of the middle Bogotá River basin. After 4 days, the sorbents were removed so that they could be desorbed and analyzed using UHPLC-MS in the laboratory. For the composite samples, the results were below the first calibration curve point (FCCP) of the chromatographic method, and for passive sampling, peaks of benzoylecgonine (BE) (21427.3 pg mL-1), methamphetamine (MET) (67101.5 pg mL-1), MDMA (ecstasy) (225844.8 pg mL-1) and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) (15908.4 pg mL-1) were found. Therefore, passive sampling could be suggested as an alternative to composite sampling for the monitoring of compounds.

Analysis of Salix humboldtiana to be used as the plant species in evapotranspirative willow systems in Latin American highland climate conditions.

This study aims to evaluate the evapotranspiration (EVP) rate of the willow species Salix humboldtiana to be used as a plant species for evapotranspirative willow system (EWS) to treat domestic wastewater in highland climate conditions in Latin America. Twelve lysimeters were installed in Bogotá, Colombia (2,600 m.a.s.l.). Two parameters were evaluated to determine the effect on EVP rate as follows: (a) the plant's age at the plantation time (one year or six months), and (b) the type of water (domestic wastewater or fertilized water). The plant's age was the most important parameter influencing the EVP rate. In addition, the growth of plants was similar (p > 0.05) between individuals irrigated with domestic wastewater and fertilized water. Thus, Salix humboldtiana over one-year-old was recommended to be used in EWS because its EVP rate of 1456 mm y-1, can treat 372 mm y-1 of domestic wastewater under the highland climate conditions. Finally, one EWS planted with Salix humboldtiana to treat domestic wastewater for a Colombian family located in these climate conditions would need an area of 400 m2. This value for area, although similar to other parts of the world, is higher when considering the solar radiation in tropical or sub-tropical climate conditions.

Tratamiento de lixiviados utilizando humedales construidos y determinación de conductividades hidráulicas en clima tropical / Treatment of leachate using constructed wetlands and determination of hydraulic conductivities in a tropical climate

RESUMEN Los humedales construidos en los últimos años han sido ampliamente usados en la depuración de una gran variedad de aguas residuales, por ser una alternativa que ofrece múltiples ventajas, en comparación con otros sistemas de tratamiento. Este estudio evaluó la eficiencia de seis sistemas de humedales, construidos de flujo subsuperficial horizontal (HCFSSH), a escala piloto, para la remoción de materia orgánica (DQO), nutrientes (N-NO3-, P-PO43-) y plomo (Pb+2), además de la incidencia del tiempo de operación sobre la conductividad hidráulica (Ks) para tratar lixiviados del Relleno Sanitario "El Ojito", del municipio de Popayán, Cauca. Tres humedales fueron plantados con Heliconia psittacorum (HCFSSH-H. p) y tres con Cyperus haspan (HCFSSH-C. h); el medio de soporte utilizado fue grava, operados con un caudal de 0.012m3/día y un tiempo de retención hidráulico de 4 días; las unidades recibieron efluente de una laguna de oxidación. Los resultados mostraron remociones medias de: DQO (51,67 y 64,00%), N-NO3- (45,33 y 48,17%), P-PO43- (53,67 y 62,67%) y Pb+2 (5,74 y 14,75%) para los HCFSSH-H. p y HCFSSH-C. h, respectivamente y valores de conductividad hidráulica, entre 700 y 1000m/día. El sistema de humedales mostró ser eficiente para el tratamiento secundario de lixiviado de rellenos sanitarios maduros, obteniendo eficiencias de remoción, significativamente mayores, en los HCFSSH-C.h.

ABSTRACT In recent years, constructed wetlands have been widely used for the purification of wastewater, representing an alternative method that offers multiple advantages when compared to other treatment systems. The present study assessed the efficiency of six horizontal subsurface flow constructed wetlands (HSSFCW) at pilot scale for the removal of organic matter (COD), nutrients (N-NO3-, P-PO43-) and lead (Pb2+). The study also looked at the operating time on hydraulic conductivity (Ks) to treat leachate from the "El Ojito" Sanitary Landfill in the municipality of Popayán, Cauca. Three wetlands were planted with Heliconia psittacorum (HSSFCW-H. p), and three with Cyperus haspan (HSSFCW-C. h). The support medium used was gravel. They were operated at a flow of 0.012m3/day, and a hydraulic retention time of 4 days. The units received effluent from the oxidation pond. The results showed mean removals of COD (51.67 and 64.00%), N-NO3- (45.33 and 48.17%), P-PO43- (53.67 and 62.67%) and Pb+2 (5.74 and 14.75%) for HSSFCW-H. p and HSSFCW-C. h respectively. Hydraulic conductivity values were between 700 and 1000m/day. The wetland system proved to be efficient for the secondary treatment of leachate from mature landfills, obtaining removal efficiencies significantly higher in HSSFCW-C. h.

A Critical Review of the Factors Affecting Modeling Oxygen Transfer by Fine-Pore Diffusers in Activated Sludge.

In this review, the factors affecting the transfer of oxygen in activated sludge processes using fine-pore diffusers for water resource recovery are critically discussed. In water resource recovery facilities, the energy required for aeration constitutes 50% to 80% of the total energy consumed by the plant. This critical review highlights the use of fine-pore diffuser aeration and emphasizes the significance of accounting for the following factors: diffuser aging and fouling, diffuser layout, diffuser type, selector benefits, local environmental conditions (temperature and atmospheric pressure), influent wastewater variability, dissolved oxygen control systems, and airflow rates. In our review, we were unable to find mathematical models that could be used to develop dynamic α-factor predictions and diffuser fouling predictions. Although the development of a model that considers all the factors that affect oxygen transfer efficiency (OTE) in activated sludge systems would be extremely valuable, the creation of such a model is outside the scope of this review.

Study of the occurrence and ecosystem danger of selected endocrine disruptors in the urban water cycle of the city of Bogotá, Colombia.

Endocrine disruptors have been studied for their high occurrence in different environments including aquatic; however, in the context of developing countries, their occurrence, magnitude and potential threat have little information. This study involved the analysis of various components of the urban water cycle in the city of Bogotá, Colombia. As a result, it was found that the compounds with the highest occurrence are plasticizers such as phthalates and bisphenol A, whereas among the drugs, carbamazepine presented the highest concentrations (0.68-31.45 µg L-1); the analysis of the threat coefficient (HQ) showed the importance of bis(2-ethylhexyl) phthalate (BEHP) and estrone (E1) that can reach surface waters from domestic and industrial discharges.

Biofortified indica rice attains iron and zinc nutrition dietary targets in the field.

More than two billion people are micronutrient deficient. Polished grains of popular rice varieties have concentration of approximately 2 µg g(-1) iron (Fe) and 16 µg g(-1) zinc (Zn). The HarvestPlus breeding programs for biofortified rice target 13 µg g(-1) Fe and 28 µg g(-1) Zn to reach approximately 30% of the estimated average requirement (EAR). Reports on engineering Fe content in rice have shown an increase up to 18 µg g(-1) in glasshouse settings; in contrast, under field conditions, 4 µg g(-1) was the highest reported concentration. Here, we report on selected transgenic events, field evaluated in two countries, showing 15 µg g(-1) Fe and 45.7 µg g(-1) Zn in polished grain. Rigorous selection was applied to 1,689 IR64 transgenic events for insert cleanliness and, trait and agronomic performances. Event NASFer-274 containing rice nicotianamine synthase (OsNAS2) and soybean ferritin (SferH-1) genes showed a single locus insertion without a yield penalty or altered grain quality. Endosperm Fe and Zn enrichment was visualized by X-ray fluorescence imaging. The Caco-2 cell assay indicated that Fe is bioavailable. No harmful heavy metals were detected in the grain. The trait remained stable in different genotype backgrounds.