Benzo[a]pyrene Emerging Micropollutant Oxidation under the Action of Fenton Reactants in Real Surface Water: Process Optimization and Application

Rubio Clemente, Ainhoa | 2019

This work evaluates the efficiency of the Fenton reaction on oxidizing 3 µg/L benzo[a]pyrene (BaP), used as a polycyclic aromatic hydrocarbon model compound due to the detrimental effects ascribed to its presence in aqueous media. For optimizing the variables affecting the oxidation capacity of the system, response surface methodology was conducted using a face-centered central composite experimental design. H2O2 and Fe(II) ion contents were studied in the range from 5 to 15 mg/L and from 0.21 to 0.63 mg/L, respectively. A poor BaP oxidation was observed in natural water since only ∼25% of BaP removal was obtained for an oxidant level of 10.50 mg/L and a catalyst concentration of 0.44 mg/L, after 90 min of treatment. Under these operating conditions, <10% of organic matter mineralization, in terms of total organic carbon, was achieved. However, by using a simpler aqueous matrix, 76.93% of BaP elimination was found; therefore, the efficiency of the process was increased by three-fold. This fact evidences the importance of performing investigations on advanced oxidation process application using real matrices; otherwise, erroneous conclusions about the efficiency of the system might be obtained. Additionally, the current work allows understanding the individual effects and relationships of the considered factors in the removal of the pollutant of interest at ultra-trace levels in a natural aqueous matrix. Keywords: Advanced oxidation processwater treatmentpolycyclic aromatic hydrocarbonresponse surface methodologyreal aqueous matrix

Comparación de técnicas alternativas de potabilización de agua, y su posible aplicación en el área rural del territorio nacional colombiano

Upegui Sosa, Sergio Augusto | 2020-08-28

El abastecimiento del agua potable en las zonas rurales de los países en desarrollo ha venido presentado diferentes dificultades, donde Colombia no es ajena a esta situación dado a la dificultad de abastecer de agua potable a las comunidades rurales, debido a la poco probabilidad de implementar sistemas convencionales que permitan el acceso al agua en las condiciones que la normatividad lo exige, por lo tanto se ha hecho necesario la implementación de técnicas alternativas a la potabilización que no impliquen costos elevados y que proporcionen al agua las condiciones necesaria para el consumo humano, por lo tanto en este artículo se realizó un análisis de las diferentes técnicas alternativas para la potabilización con el fin de analizar su posible aplicación en el territorio nacional. Los resultados demostraron que estas técnicas no requieren de grandes inversiones y de tecnologías sofisticadas lo cual hace posible que las comunidades puedan acceder al agua potable mediante la práctica de sistemas naturales y alternativas simples.

Comparison of microbial and physicochemical behavior of expanded granular sludge bed system during methylparaben and triclosan removalWater Science & Technology

Castrillón Cano, Laura Victoria | 2019

Methylparaben and triclosan are antimicrobial agents widely used as preservatives in a variety of personal care and pharmaceutical products. Wastewater is considered the main source of these compounds in the environment. Expanded granular sludge bed (EGSB) reactors are a high rate technology for wastewater treatment based on biological processes and have been shown to be efficient in removing different types of compounds; however, little is known about the effect of contaminants such as methylparaben and triclosan on their behavior and effectiveness. In this study, we evaluate and compare the microbial and physicochemical behavior of EGSB systems during methylparaben and triclosan removal. The presence of different concentrations of pollutants had an influence on the cluster organization of microbial communities, especially bacteria. However, this did not affect the stability and performance of the EGSB systems. The banding patterns of the denaturing gradient gel electrophoresis of archaea demonstrated the constant presence and abundance of Methanosaeta concilii throughout all stages of operation, showing that this microorganism played a fundamental role in the stability of the reactors for the production of methane. The type of compound and its concentration influenced the expression of the mcrA and ACAs genes; however, these changes did not alter the stability and performance of the EGSB systems Key words | anaerobic digestion, emerging pollutants, microbial communities, water treatment

Efficiency of the removal of microcystin-LR by UV-radiation and hydrogen peroxide

Loaiza González, Jinna Marcela | 2020

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

Evaluation of the UV/H2O2 system for treating natural water with a mixture of anthracene and benzo[a]pyrene at ultra-trace levels

Rubio Clemente, Ainhoa | 2018

The presence of polycyclic aromatic hydrocarbons, such as anthracene (AN) and benzo[a]pyrene (BaP), in water has become a problem of great concern due to the detrimental health effects caused to humans and living beings. In this work, the efficiency of the UV/H2O2 system for degrading the target compounds at ultra-trace levels in surface water has been evaluated. For this purpose, a previous optimization step using a face-centered central composite experimental design has been conducted, considering the effect of the UV-C irradiance and the initial concentration of H2O2. It was evidenced that under optimal operating conditions (11 mg L−1 H2O2 and 0.63 mW cm−2 irradiance), AN and BaP removal percentages were higher than 99.8%. Additionally, 69.3% of the organic matter, in terms of total organic carbon, was mineralized without the production of transformation by-products more harmful than the parent compounds. These findings demonstrate the oxidation capacity of the examined system in a natural matrix for degrading micropollutants that cannot be converted through conventional treatment processes. Consequently, new horizons are opened for the effective use of the UV/H2O2 system for drinking water production, providing the accomplishment of other regulated parameters related to water quality.

Informe Final de Prácticas interinstitucionales en la Secretaria de Desarrollo Social, Alcaldía del Municipio de Nueva Caramanta, Antioquia

López Jaramillo, Camilo Ernesto | 2020-08-28

El medio ambiente se define como el conjunto de factores físico-naturales, sociales, culturales, económicos y estéticos que interactúan entre sí, con el individuo y con la sociedad en que vive, determinando su forma, carácter, relación y supervivencia (Álvarez et al., 2008). Sin embargo, los recursos están siendo afectados por la contaminación que genera la actividad del hombre. Problemas ambientales como la destrucción de la capa de ozono, el incremento del efecto invernadero, el cambio climático, la alteración de ciclos hidrológicos, la deforestación y la pérdida de la biodiversidad son el resultado de la ausencia de cultura y la poca educación ambiental en las personas. Con el objetivo de brindar un apoyo en el aspecto ambiental del municipio de Nueva Caramanta, se lleva a cabo la etapa de práctica académica en la oficina de Desarrollo Agropecuario y Ambiental perteneciente a la Secretaría de Desarrollo Social del municipio de Nueva Caramanta, en esta dependencia se realizan acciones encaminadas a la disminución de los impactos ambientales, a contribuir al cambio de los estilos de vida desde el componente educativo-ambiental que facilite la conservación de los recursos naturales, las cuales hacen parte del trabajo que se debe apoyar como practicante de Ingeniería ambiental. Estas acciones mencionadas, facilitan el que hacer de la administración municipal partiendo de un diagnóstico claro que faciliten priorizar y definir acciones estratégicas en bien de la salud, el patrimonio ambiental y el mejoramiento de la calidad de vida de la comunidad de Caramanta.

Optimización del proceso sono-foto-Fenton para el tratamiento de aguas residuales usando un diseño central compuesto

Castrillón Marín, Mateo | 2021

Introducción. Debido al aumento de la toxicidad de las aguas residuales y a la limitada eficiencia de los sistemas convencionales, se hace necesaria la aplicación de procesos alternativos, entre los que destaca el sistema sono-foto-Fenton. Objetivo. Con este trabajo se busca optimizar las variables que afectan directamente el poder de oxidación del proceso sono-foto-Fenton, tales como el pH de la solución y la concentración de agente oxidante y promotor, para el tratamiento de un agua residual de origen petroquímico, con el fin de validar la conveniencia del uso de diseños de experimentos basados en un número reducido de corridas. Materiales y métodos. Para ello, se utilizó un diseño de experimentos central compuesto centrado en las caras, cuyo modelo de regresión de segundo orden obtenido fue validado. Los resultados alcanzados fueron comparados con los reportados en la literatura usando un mayor número de corridas experimentales. Resultados. Bajo condiciones de operación optimizadas (3 unidades de pH, 525 mg/L de H2O2 y 25,70 mg/L de Fe2+) se obtuvieron remociones de DQO > 70 %. Estos resultados fueron similares a las condiciones óptimas obtenidas e informadas previamente en la literatura utilizando un diseño de experimentos factorial completo. Conclusiones. Se demuestra, por tanto, la importancia de llevar a cabo diseños de experimentos que permitan optimizar sistemas de tratamiento de aguas usando un reducido número de corridas, lo cual se traduce en la reducción tanto de costos económicos como de tiempos de experimentación y análisis de la variable respuesta objeto de estudio. Palabras clave: diseño de experimentos, tratamiento del agua, proceso avanzado de oxidación, contaminante persistente, contaminación.

Photovoltaic array for powering advanced oxidation processes: Sizing, application and investment costs for the degradation of a mixture of anthracene and benzo[a]pyrene in natural water by the UV/H2O2 system

Rubio Clemente, Ainhoa | 2018

Advanced oxidation processes (AOPs) are commonly known as efficient water treatment techniques able to oxidize a great variety of pollutants from water that are otherwise difficult to be converted. Nevertheless, AOPs are costly processes, particularly, because of the electrical costs associated. In this regard, photovoltaic (PV) energy can be used to power the AOP in a reliable and autonomous way. In this work, the steps for sizing a solar PV system for water treatment using AOPs are described. Additionally, the feasibility of the use of a PV array without batteries to supply the electrical power needs of a UV/H2O2 advanced oxidation system for degrading natural water containing 12 and 3 μg L−1 of anthracene and benzo[a]pyrene, respectively, two of the priority polycyclic aromatic hydrocarbons because of their harmful effects on living beings, was studied. It was found that more than 99% of anthracene and benzo[a]pyrene were removed and about 45% of the total organic matter was mineralized after 15 and 90 min of treatment, indicating the high efficiency of the system. Finally, the investment costs of the UV/H2O2-PV system for a small application were estimated with and without batteries in order to define the optimum PV array configuration. The PV array designed and applied allows for the decontamination of persistent pollutants in natural water in an environmentally-friendly and sustainable way.

Total coliform inactivation in natural water by UV/H2O2, UV/US, and UV/US/H2O2 systems

Rubio Clemente, Ainhoa | 2019