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Studies of emissions of greenhouse gas (GHG) such as CO2 and CH4 in hydroelectric reservoirs are very important in the debate on whether hydropower can be classified as a ‘clean energy’ source. In this study, GHG emissions in the Topocoro reservoir in Colombia during the first five years after filling were evaluated and related with hydropower generation. The floating static chamber and inverted funnel methodology were used for the collection of GHG and the gas chromatography with flame ionization detector (FID) – methanizer and electron capture detector (ECD) methodology for its detection in the laboratory. The results showed emission values between 256,613 and 654,643 tCO2eq/year. The intensity of gases was also determined in a range between 81 and 148 gCO2eq/kWh, depending on the evolution of the filling and the power generation in the reservoir. The results suggested that as the filling percentage of the surface of the reservoir increases, there will be more GHG emissions, due to the biotic and abiotic decomposition of organic matter. At the same time, higher energy production will be generated. HIGHLIGHTS A tropical reservoir in Colombia was monitored for five years during the post-filling phase.; The floating static chamber and inverted funnel methodology were used.; It analyzed the relationships of the GHG with energy production and power density in the reservoir.; This is the first investigation carried out in Colombia to determine the net emissions in a reservoir.;

Due to the negative effects caused to the natural environment by the presence of pharmaceutical-type traces and other pollutants in wastewater, it is necessary to develop and optimize efficient treatment systems. This study evaluated the effect of carbamazepine (CBZ) and diclofenac (DCF) on the behavior of seven EGSB (expanded granular sludge bed) anaerobic reactors at laboratory scale, using chromatographic and physicochemical analyses of the influent, effluent, and the biomass contained in the reactors. The results showed that CBZ had a greater effect on the removal and behavior of microorganisms than DCF, with average efficiencies of 34.04 ± 18.58%, 20.76 ± 8.51% and 16.29 ± 11.08% during stage II, III and IV, respectively, for CBZ, and 92.37 ± 12.74%, 26.77 ± 5.90% and 22.28 ± 9.60% during stage II, III and IV, respectively, for DCF. Additionally, it was found that the interaction of the co-substrate used (sodium acetate) in conjunction with the pharmaceutical compounds decreased the efficiency of the system in terms of the removal of analytes. HIGHLIGHTS This study evaluated the effect of carbamazepine and diclofenac in EGSB reactors.; The results showed that carbamazepine had a greater effect on the removal and behavior of microorganisms.; The presence of an additional carbon source decreases the removal efficiency of the pharmaceutical product.;

Tropical reservoirs are generally flooded in soils with a high content of organic matter. This, combined with high temperatures, favors the generation of carbon dioxide and methane by biological degradation, contributing to the impact on climate change. A tropical reservoir in Colombia was monitored for 7 years in the pre-fill, fill and post-fill stages, for the last of these during the day and night. Emissions from diffusive fluxes at the surface of the water were measured using a floating static chamber, while inverted funnel methodology was used to measure the fluxes by bubbling. The samples collected in the field were analyzed in the laboratory using a gas chromatograph with a mass detector. The results showed average emissions of 70892.51±41079.16-ton CO2eq/year for pre-filling; 178254.53±105838.01-ton CO2eq/year for filling; and 466946.57-ton CO2eq/year for post-filling (for 5 years), concluding that the weather conditions and the filling percentage had an impact on the generation of greenhouse gases at filling and post-filling stages, as did the organic matter present in the area of influence of the sampling point. Higher greenhouse gas emissions were found during the day compared to the results at night, indicating that temperature affects these processes especially in tropical reservoirs. HIGHLIGHTS A tropical reservoir in Colombia was monitored for 7 years during the pre-filling, filling and post-filling phases.; The main contribution is the estimation of GHG in a tropical reservoir using a floating static chamber and the inverted funnel method.; This is the first investigation carried out in Colombia to determine the net emissions in a reservoir.;

This study presents the main results related to the use of activated persulfate (PS) in the elimination of the beta-lactam antibiotic cephalexin (CPX). Experiments were done using K2S2O8 and simulated sunlight. A face-centered central composite experimental design was used to analyze the effects of the solution pH and the PS concentration on the reaction, and to determine the optimized conditions that favor the CPX elimination. The results indicated that the removal of CPX is promoted by an acidic pH and under the higher evaluated PS dose (7.5 mg L−1). CPX total removal was achieved in 30 min. The analysis of the effect of the pollutant initial concentration indicated that a pseudo-first-order kinetics model can be used to describe the reaction. Likewise, the use of Fe2+ ions for PS activation (in the dark) was evaluated and established that a higher concentration of ions favors the pollutant removal. Control tests and under the presence of scavenger agents indicated that both HO• and SO4−• radicals would be present in the solution and promote the CPX elimination. The assessment of the solution dissolved organic carbon, nitrates and sulfates was also carried out, and indicated that a portion of the organic matter was mineralized. HIGHLIGHTS Antibiotic cephalexin was eliminate using persulfate and simulated sunlight.; Antibiotic total elimination was achieved in 30 min.; Ferrous ions can activate persulfate and promote cephalexin removal in water.; HO• and SO4−• radicals would be present in the solution.; Part of the organic matter was mineralized.;

The efficiency of a helical flow photoreactor in the oxidation of the antibiotic Dicloxacillin as a function of the recirculation flow, the local volumetric rate of photon absorption (LVRPA) and photonic efficiency using oxidation processes based on UV-C/H2O2 and UV-A/photo-Fenton were evaluated in this work. Mathematical modeling of the degradation process and experiments in lab-scale helicoidal reactor were done. Mathematical evaluation was supported in function of photon flux, mass balance and reaction rate law. The LVRPA was calculated by modified Beer-Lambert Equation. The effect of the concentration of hydrogen peroxide and iron (II) on the efficiency of the oxidation of the antibiotic Dicloxacillin was evaluated by means of the photo-Fenton. In 45 min, 100% degradation of dicloxacillin was achieved using 1.5 mM H2O2 and 7.32 μM ferrous ion in the photo-Fenton experiments with the helical flow photoreactor. The optical thickness of the reaction and distribution of energy absorption confirmed the kinetic and photonic efficiency performance. The prediction of the model presented a global error less to 2.4% between experimental and simulated data.

Chlorpyrifos formulations are the most used in Colombia and other countries for crop protection, and their presence has been proven in many water sources. The application of nanomaterials, including carbon quantum dots (CD), can significantly improve the performance of optical biosensors for quick and accurate detection of these pesticides. In this work, naturally fluorescent and nontoxic CD were conjugated with acetylcholinesterase (AChE) as a bioreceptor, to produce a fluorescent biosensor. This system was modulated with graphene oxide (GO), showing a fluorescence recovery in the presence of the pesticide. The biosensor was evaluated for the detection of pure chlorpyrifos (CPF), profenofos (PF), and a commercial formulation called Lorsban®. A limit of detection (LOD) as low as 0.14 and 2.05 ppb for chlorpyrifos and Lorsban®, respectively, was obtained. Profenofos did not show any recovery with this system at the evaluated concentrations. The system also showed a good selectivity in the presence of proteins (BSA) and other organic substances (Glucose) usually present in drinking water. The specificity was also evaluated against cypermethrin and methomyl commercial formulations showing minimal interference. To the best of our knowledge, this is one of the few works reporting the detection of commercial pesticide formulations with promising results.

Azithromycin (AZT) is a broad-spectrum antibiotic from the group of macrolides that acts against several Gram-positive and Gram-negative bacteria, which has promoted its use in the treatment of different respiratory and sexually transmitted diseases. However, its presence in environmental matrices and in the effluents of conventional wastewater treatment plants has been evidenced in recent years, which reflects the need to develop new treatment alternatives that allow its total removal and minimize the eventual adverse effects, selection of resistant bacterial strains, associated with its presence in water bodies.Simulated sunlight radiation and H2O2 were used to remove AZT from water assessing the effects of operational parameters like the solution initial pH and the peroxide concentration. Results indicate that hydroxyl free radical is the main responsible for pollutant removal but acidic solution conditions and larger H2O2 doses negatively affect OH• generation under the evaluated experimental conditions. Pollutant removal was almost complete after 120 min of photo-treatment. In addition, reduction of the organic carbon content in the treated samples was ∼50.0%; and a significant increase of nitrates concentration in solution was evidenced.

The complexes derived from 6-methoxyquinoline ZnCl2(6OMeQ)2 have been shown to be effective as singlet molecular oxygen photosensitizers, which can be interesting for the removal of microcontaminants such as Bisphenol A (BPA) and Triclosan (TCS). Photodegradation with eosin Y (EOY) was also carried out as standard photosensitizer. Due to the physicochemical characteristics of these synthesized photosensitizers, the analysis was carried out in a homogeneous system in simulated effluents. An experimental design was made, based on previous studies and supporting literature. It was established that, at pH 5 and at 0.00104 mM EOY concentration, 20% removals were obtained in the case of BPA. Then, using the same photosensitizer with TCS it was possible to establish photodegradation up to 56% at the same pH but at a temperature of 50 °C, associating this result with the increase in temperature generated, and an increase in speed being reflected in the results obtained. Photodegradation using the coordinated compound, at pH 5.0, and 0.00119 mM photosensitizer concentration, a 26.7% of BPA photodegradation was obtained and, at 50 °C and pH 6, a 52.3% of TCS photodegradation was obtained. This photosensitizer is comparable for the removal this kind of the micropollutant. The experiments were made with UV/VISIBLE Lamps and monitored for HPLC, and some subproducts were analyzed for GC/MS.

Cephalexin (CPX) and doxycycline (DOX) are two of the most used antibiotics to treat bacterial infections in human medicine, veterinary practices, animal husbandry, agriculture, aquaculture, among others. Nevertheless, due to their excessive consumption and incomplete absorption during their metabolization, they have been detected in different environmental matrices and the effluents of wastewater treatment plants, which reflects that conventional water treatment methods are not enough to eliminate this type of compounds. This paper presents the main results about the removal of the antibiotics CPX and DOX under low frequency (40 kHz) ultrasonic radiation (US). The effects of operational parameters such as the solution initial pH and the applied US power were assessed considering the response surface methodology and a face centered, central composite experimental design. The results indicated that evaluated operational factors significantly affect the pollutants elimination and that US technology is able to remove them completely. In addition, in terms of mineralization, experimental results showed a reduction of the organic carbon present in the solutions and a significant increase of ions (nitrates and sulfates) concentration, suggesting that part of the organic matter was transformed into CO2, H2O and inorganic species. Finally, results regarding the samples toxicity indicated that ultrasonic treatment could promote a significant reduction in this parameter, and the potential negative effect associated to CPX and DOX presence in water bodies.

The reaction rate constants concerning the removal of benzo[a]pyrene (BaP) and anthracene (AN) in water by the Fenton process can be commonly found from the experimental data and by using regression models. However, this calculation is a time-consuming and a difficult task. Therefore, an algorithm for the determination of the rate constants depletion of the pollutants of interest should be developed. In this study, several algorithms were developed, using MATLAB® software for representing AN and BaP elimination by the Fenton process under an experimental domain. These algorithms were derived from the first-, second- and third-order kinetic models, as well as from the double exponential and the Behnajady-Modirshahla-Ghanbery (BMG) kinetic models. Regarding the AN and BaP removal kinetics, the double exponential and the BMG models were found to exhibit the highest correlation coefficients (>0.98 and >0.95, respectively) in comparison with those ones obtained from the first-, second- and third-order kinetic models (>0.80, >0.85 and >0.88, respectively). It was found that the algorithms can be used to optimize and fit the rate constants by creating an objective function that fits and represents the experimental data obtained concerning the removal of the compounds of interest through the Fenton advanced oxidation process.

Se evaluó la variación en las poblaciones microbianas y el comportamiento de un sistema SBR en la eliminación de metilparabeno (MePB). La experimentación se llevó a cabo en tres etapas: (Etapa I: aclimatacion), (Etapa II = 300 μgMePB / L y Etapa III = 600 μgMePB / L). La variación de los microorganismos se analizó durante el tiempo de experimentación junto con el contacto con MePB y el porcentaje de eliminación de DQO, con resultados de 88 ± 5,5% y 92 ± 7,7% respectivamente. Se evaluó la eliminación cinética de MePB para obtener la constante de velocidad de degradación biológica, Kbiol. Usando estos resultados cinéticos, se evaluó el efecto de diferentes concentraciones de MePB y biomasa en el comportamiento de la biodegradación. Se obtuvieron valores de Kbiol (LgSS-1d-1) de 42.8 y 79 respectivamente; y 472 ± 38.0 µgMePB / L, a contenidos de biomasa de 1466.7 y 2666.7 mgSSV / L, donde se obtuvieron valores de Kbiol (LgSS-1d-1) de 11.0 y 32.6 respectivamente.La variación de las poblaciones microbianas se analizó utilizando DGGE. Los resultados indicaron que las poblaciones presentaron características similares entre las etapas, pero para las muestras de biomasa de Etapa I y Etapa III, se identificaron diferencias significativas en la composición de las poblaciones microbianas. No obstante, esto no afectó la eliminación de MePB y las condiciones de diversidad que caracterizan a un sistema aeróbico.

Herbicide 2,4-D is one of the most widely used in the world. In this way, its presence on different bodies of water has been reported. In this paper the efficiency of horizontal-subsurface flow constructed-wetlands for 2,4-D removal in aqueous solutions was assessed. Wetlands were constructed using fiberglass, and grown with Phragmites australis. The influent consisted of synthetic wastewater under different 2,4-D and glucose initial concentrations. Results indicated that, under the evaluated experimental conditions, 2,4-D extent of removal was between 71.0 and 99.0%. In general, it can be noted that an increase in the herbicide concentration reduces the removal efficiency, probably due to a toxic effect on the biological component. On the other hand, the influent dissolved organic carbon (DOC) initial concentration had a significant effect on the removal of both, the herbicide and the organic matter content in the system, demonstrating that this parameter has a significant effect on this kind of biological methods for water treatment. Finally, it can be concluded that constructed wetlands are a viable alternative for the treatment of wastewater contaminated with the herbicide 2,4-D. Keywords: 2,4-D, Constructed wetlands, Herbicides, Phragmites australis, Wastewater treatment

The efficiency of biological wastewater treatment systems is linked fundamentally to the hydraulic performance of each treatment unit. These units should guarantee an adequate contact between the microorganisms and the residual water, and the compliance with the hydraulic retention time established, in order to decrease the number of dead zones or short circuits that may exist inside the reactors. In this work, hydraulic performance was evaluated in seven Expanded Granular Sludge Bed (EGSB) reactors with a useful volume of 3,4 L and constructed in acrylic. The analysis was carried out through the stimulus-response test, using bromide as tracer. Two hydraulic retention times (8 and 24 h) and the effect of the presence of granular biomass were considered. Results were analyzed qualitatively through the construction of curves C, E and F, and quantitatively through the construction of a mathematical model of axial dispersion. The results of the hydraulic performance of the reactors revealed a marked tendency to a complete mix flow pattern, with a low effect of HRT or the presence of granular biomass on their operation.

Due to the harmful effects associated with the presence of microcystin-LR (MC-LR) cyanotoxin, photo-degradation assays were performed in natural and distilled water using the combined action of ultraviolet (UV) radiation and hydrogen peroxide (H2O2). The effect of H2O2 content and UV irradiance was evaluated and optimized using a multilevel factorial design in distilled water spiked with 20 µg L-1 MC-LR. The coupled UV/H2O2 system under optimal operating conditions (0.63 mW cm-2 irradiance and 30 mg L-1 H2O2) was more effective than the individual action of UV irradiance or H2O2 content for 30 min of treatment time, since a reduction of 97.78% of MC-LR was achieved. After optimizing the operating conditions, they were applied for natural water, obtaining MC-LR removals similar to those achieved with distilled water (99.59 and 99.73%, respectively), reaching a final MC-LR concentration in both matrices well below the maximum recommended limit established by WHO for MC-LR in drinking water, fixed at 1 µg L-1. 15 mg L-1 of H2O2 were also tested, and although 98.08% of MC-LR elimination was found for a reaction time of 60 min, WHO advisable limit was not surpassed. The UV/H2O2 process could be considered as an alternative to the conventional processes water facilities are operating with to tackle the problem of fresh water pollution with cyanotoxins, providing the accomplishment of the whole set of water quality standards included in the legislation.

The growing interest in nanomaterials with advanced optoelectronic properties has promoted the advancement of biosensors with various applications. In the environmental field, the need for rapid detection of pollutants in water sources has opened the door to fluorescent biosensors. These systems are quite sensitive and simple. Nanomaterials such as carbon dots (CD), quantum dots (QD), gold nanoparticles, nanoclusters, graphene (G), graphene oxide (GO), transition metal dialcogens (TMDC) and organometallic frameworks (MOF), have been used in the development of fluorescent detection systems. They are usually based on the Förster resonance energy transfer (FRET) quenching principle. Nanomaterials can be bioconjugated with molecules such as antibodies, enzymes or aptamers, to achieve specific detection of the target pollutant, even in real samples. This review conducts a critical analysis of the operating principle of different nanomaterial-based fluorescent biosensors. We discuss the detection of substances of high concern like heavy metals, pesticides, and so-called emerging contaminants. The advantages and disadvantages of the methods are discussed, as well as recommendations for future approaches and a possible massification of these systems.

Azithromycin (AZT) is a broad-spectrum antibiotic present in different aqueous matrices due to its incomplete removal using conventional water treatments. Ultrasound (US) is an advanced oxidation technology that has demonstrated its capacity to degrade different types of organic molecules due to the generation of cavitation bubbles or cavities that promote the generation of radicals.In this paper, data regarding the use of low-frequency US (40 kHz) in the removal of AZT are presented. Tests were carried out at lab scale for 60 min considering a reaction volume of 300 mL (pollutant initial concentration 1.0 mg L−1). The effect of operational parameters such as pH, ultrasound power, the presence of external agents like ferrous ions, hydrogen peroxide, and UV radiation were evaluated. In general, obtained data show that under the experimental reaction conditions, it is feasible to reach extents of AZT removal ∼50.0%, and that the presence of other species in the medium could inhibit the reaction, mainly due to scavenging effects. This information is relevant to future applications of US, at pilot or real scale, in the treatment of water with presence of AZT or similar organic pollutants.

Gulf of Urabá is considered a tourist zone of Antioquia Department attracts a large number of visitors to explore the aquatic ecosystem and beaches thus offering a large economic benefit. However, this region has been affected by various anthropogenic effects thus generating an environmental problematic that affect aquatic ecosystem. Over the years, several research has been evaluated pollutant such as pesticides, metals and physicochemical parameters, even our laboratory had found several toxic metals in fish from this same area.The presence of emerging pollutant in matrices such as seawater and fish from Gulf of Urabá have not been reported, and to the best of our knowledge, this is the first study. This work presents important aspects relating to sampling, monitoring and surveillance of seawater and several fish species caught in the area in order to determinate the content of emerging pollutant (triclosan, ibuprofen, diclofenac) using UPLC-QqQ/MS. In general, all three pharmaceuticals in different sampling sites were detected and total concentrations ranged from 0.10 to 1.54 μg/L in surface water. However, emerging pollutants content in fish muscle was not detected. In addition, a high variability in triclosan, ibuprofen and diclofenac concentrations according to the season of sampling was found. Regarding to seasonal variations, most emerging pollutant in the surface water had variation in levels both dry and wet season. Better removal was presented in the dry season, due to stronger irradiation and greater activity of microorganisms.

Cephalexin (CPX) is a β-lactam antibiotic widely used to treat bacterial infections in the respiratory tract, skin, bones, and ear; a situation that has contributed to its discharge into wastewater (mainly through excretion after ingestion) and its accumulation in water bodies. CPX presence on environmental compartments could interfere in the physiological functions of animals and humans due to the induction of mutagenic and carcinogenic effects.Different technologies have been evaluated to remove CPX from aqueous matrices. In this way, this work presents the main data regarding the use of the combination of hydrogen peroxide and simulated sunlight radiation in CPX removal. Effects of H2O2 initial concentration and solution pH were evaluated using a face-centered, central composite design and the response surface methodology. Optimized conditions, under the evaluated experimental range, were established. In addition, data about the total organic carbon and anions content in treated samples were collected.These data can be useful for the evaluation of the use of H2O2 and light radiation on organic pollutants removal, the comparison of the effectiveness of different technologies on CPX elimination, and as a starting point to carry out this type of process at pilot or real scale.

Para una muestra de 25 ciudades de diversos países del mundo, se recogió información sobre la calidad anual del aire para PM2.5, NO2 y ozono y sobre diversos parámetros de interés en cuanto a su relación potencial con la calidad del aire. Un análisis comparativo de dicha información y un modelo lineal que relaciona la calidad del aire con algunos de los parámetros es elaborado, con base en el nivel de aproximación que se logró entre las calidades reportadas y las predichas por la modelación. Los datos se basan en reportes e información disponible en páginas web y en reportes públicos e informes de investigación propios para los años 2012 y 2015. Se ha logrado plantear una perspectiva novedosa de la situación de la calidad del aire y del tipo de medidas estratégicas que se pudieran emprender para lograr mejorar la situación y llevarla a los límites deseables.

Cervantes, S. P., Londoño, Y. A., Gutiérrez, F. R., & Peñuela, G. A. (septiembre-octubre, 2017). Evaluación de humedales artificiales de flujo subsuperficial en la remoción de diferentes concentraciones de ibuprofeno empleando Cyperus papyrus. Tecnología y Ciencias del Agua, 8(5), 105-116. Este estudio evaluó la remoción del ibuprofeno de aguas sintéticas mediante humedales artificiales de flujo subsuperficial horizontal. Se utilizaron tres humedales: dos de ellos plantados con Cyperus papyrus y el otro sin plantar. Se estabilizaron durante un mes y posterior a este periodo se adicionó al afluente del humedal ibuprofeno a tres concentraciones. Para la determinación de la concentración del ibuprofeno se utilizó cromatografía líquida acoplada a espectrometría de masas en tándem (UPLC-MS/MS); también se dio seguimiento a los humedales del carbono orgánico disuelto, demanda química de oxígeno, oxígeno disuelto, pH y conductividad eléctrica tanto en el afluente como en el efluente y conteo de heterótrofos en la grava de los tres humedales. Se comprobó que con los humedales plantados se obtuvieron mayores porcentajes de remoción de ibuprofeno que con el humedal sin plantar, obteniéndose un máximo de 84% en los humedales plantados y un máximo de 51% en el humedal sin plantar; asimismo se observó que a mayor concentración del fármaco se tuvo una menor remoción.

Este trabajo evaluó el efecto de los compuestos liberados durante la renovación de raíces de cuatro plantas: Avena sativa, Brachiaria decumbens, Brassica juncea y Medicago sativa, en la degradación de seis congéneres de bifenilos policlorados (PCBs) en un suelo contaminado con Aroclor 1260. Los ensayos se realizaron en microcosmos con 20 g de suelo a los cuales se les adicionaron triturados de raíces de las plantas cultivadas en suelo contaminado con PCBs y se usaron como controles: suelo con bifenil y con ácido salicílico y suelo sin adiciones. Los microcosmos se incubaron durante 45 días en condiciones controladas. Al finalizar la incubación se tomaron muestras para la determinación de la concentración de los PCB 44, PCB66, PCB118, PCB138, PCB153, PCB180 y PCB170, del gen BphA1 y determinación de la hidrólisis de fluoresceína. También se analizaron los extractos obtenidos de la raíz para identificar metabolitos secundarios. En los microcosmos con Brassica juncea y con bifenil se observó disminución de la concentración de los PCB66, 118 y 138. Así mismo, en estos microcosmos se observó mayor concentración del gen BphA1 y de fluoresceína. Los análisis de los extractos de raíz permitieron identificar diferentes metabolitos secundarios asociados con las plantas, siendo los extractos de la planta Brassica juncea donde se detectó mayor número de metabolitos. Los resultados permitieron comprobar el efecto de los compuestos liberados por las raíces de ciertas plantas sobre las poblaciones microbianas del suelo con capacidad de degradar PCBs.

La toxicidad de las aguas residuales provenientes de empresas de procesamiento de productos cárnicos fue evaluada antes y después del tratamiento usando un reactor secuencial por lotes (SBR). Las pruebas de toxicidad fueron evaluadas mediante el análisis del efecto inhibidor de muestras en relación con la emisión de luz a partir de bacterias marinas de la especie Vibrio fischeri. Los resultados demostraron que los efluentes antes del tratamiento eran altamente tóxicos (EC50 < 60%), mientras que los resultados después del tratamiento mostraron baja o nula toxicidad (EC50 > 82%). En algunas etapas operativas del reactor SBR, se encontró correlación entre el nitrógeno amoniacal presente en cada muestra y la toxicidad de las aguas residuales tanto en el afluente y los efluentes, con correlaciones (R2) de 0,6141 y 0,8158, respectivamente. Como consecuencia de estos resultados, el sistema SBR puede ser considerado eficiente en la eliminación de materia orgánica y nitrógeno, y de ese modo disminuir la toxicidad en el agua tratada.

Resumen Objetivo: optimizar un sistema de tratamiento de aguas residuales de cultivos de flores, con el fin de mejorar la eficiencia en la remoción de los contaminantes, usando humedales construidos de flujo subsuperficial-horizontal. Metodología: se realizó un estudio de tipo exploratorio experimental en dos etapas, en la primera se efectuó el acondicionamiento fisicoquímico y biológico del sistema de tratamiento, en la segunda, se llevó a cabo el seguimiento de la remoción de los contaminantes durante nueve meses, para lo cual se monitoreó la demanda química de oxígeno, demanda biológica de oxígeno, sólidos totales, sólidos suspendidos totales, pH y oxígeno disuelto. Resultados: Se logró mejorar la eficiencia del sistema de tratamiento en 7,1% para la Demanda biológica de oxígeno, 4,1% Demanda química de oxígeno, 56,9% sólidos totales y 117,2% solidos suspendidos totales. Conclusión: La concentración de DQO disminuyó con el tratamiento primario (Precipitación y oxidación química) y favoreció la eficiencia del sistema de tratamiento secundario, dado que las aguas a tratar tenían valores muy altos de DQO que pueden saturar los humedales con contaminantes persistentes. Se podrían obtener mayores eficiencias, si se logra mejorar el sistema de tratamiento primario. Abstract Objective: to optimize the wastewater treatment system of flower crops in order to improve pollutant removal efficiency, using a horizontal subsurface flow constructed wetland. Methodology: An exploratory experimental study was conducted in two stages; in the first stage the treatment system was conditioned physically, chemically and biologically. In the second stage pollutant removal was monitored for nine months. To achieve this, chemical oxygen demand, biological oxygen demand, total solids, total suspended solids, pH and dissolved oxygen were monitored. Results: It was possible to improve the efficiency of the treatment system in 7.1% for biological oxygen demand, 4.1 % for chemical oxygen demand, 56.9 % for total solids and 117.2 % for total suspended solids. Conclusion: the concentration of COD decreased with the primary treatment (precipitation, chemical oxidation) and favored the efficiency of the secondary treatment system since the water to be treated had very high values of COD which may saturate the wetlands with persistent pollutants. Higher efficiency could be obtained by enhancing the primary treatment system.

Emerging pollutants are compounds of increased environmental importance and, as such there is interest among researchers in the evaluation of their presence, continuity and elimination in different environmental matrices. The present work reviews the available scientific data on the degradation of emerging pollutants, mainly pharmaceuticals, through ultrasound, as an advanced oxidation process (AOP). This study analyzes the influence of several parameters, such as the nature of the pollutant, the ultrasonic frequency, the electrical power, the pH, the constituents of the matrix and the temperature of the solution on the efficiency of this AOP through researches previously reported in the literature. Additionally, it informs on the application of the referred process alone and/or in combination with other AOPs focusing on the treatment of domestic and industrial wastewaters containing emerging pollutants, mainly pharmaceuticals, as well as on the economic costs associated with and the future perspectives that make ultrasound a possible candidate to solve the problem of water pollution by these emerging pollutants..

Coffee is one of the most consumed beverages in the world and is crucial in the economy of many developing countries. The search to improve coffee quality comes from many fronts, as do the many ways to measure quality and the factors that affect it. Several techniques are used to measure the different metrics to assess coffee quality, across different types of coffee samples and species, and throughout the entire process from farm to cup. In this work, we conducted a systematic mapping study of 1,470 articles to identify the aspects of quality that are the most important in the scientific literature to evaluate coffee throughout the processing chain. The study revealed that cup quality and biochemical composition are the most researched quality attributes. The main objective of the reviewed studies is the correlation between different quality measurements. The most used techniques are the analytical chemistry methods. The most studied species is Coffea arabica. The most used sample presentation is green coffee. The postharvest stage is the most researched, in which quality control receives more attention. In the preharvest stage, management practices stand out. Finally, the most used type of research was the evaluation research.