Browsing by Author "Muñoz Arango, Diana Carolina"

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    Perchlorate and chlorate assessment in drinking water in northern Chilean cities
    (2023) Muñoz Arango, Diana Carolina; Torres Rojas, Felipe Ernesto; Tapia Flores, Natalia F.; Vega Muñoz, Marcela Natalia; Alvear, Cristóbal; Pizarro, Gonzalo; Pastén González, Pablo Arturo; Cortés Arancibia, Sandra; Vega Contreras, Alejandra Soledad; Calderón, Raúl; Nerenberg, Robert; Vargas, Ignacio; CEDEUS (Chile)
    Perchlorate and chlorate are endocrine disruptors considered emerging contaminants (ECs). Both oxyanions are commonly associated with anthropogenic contamination from fertilizers, pesticides, explosives, and disinfection byproducts. However, the soils of the Atacama Desert are the most extensive natural reservoirs of perchlorate in the world, compromising drinking water sources in northern Chile. Field campaigns were carried (2014–2018) to assess the presence of these ECs in the water supply networks of twelve Chilean cities. Additionally, the occurrence of perchlorate, chlorate and other anions typically observed in drinking water matrices of the Atacama Desert (i.e., nitrate, chloride, sulfate) was evaluated using a Spearman correlation analysis to determine predictors for perchlorate and chlorate. High concentrations of perchlorate (up to 114.48 μg L−1) and chlorate (up to 9650 μg L−1) were found in three northern cities. Spatial heterogeneities were observed in the physicochemical properties and anion concentrations of the water supply network. Spearman correlation analysis indicated that nitrate, chloride, and sulfate were not useful predictors for the presence of perchlorate and chlorate in drinking water in Chile. Hence, this study highlights the need to establish systematic monitoring, regulation, and treatment for these EC of drinking water sources in northern Chilean cities for public health protection.
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    Synergistic effect of electrotrophic perchlorate reducing microorganisms and chemically modified electrodes for enhancing bioelectrochemical perchlorate removal
    (2023) Torres Rojas, Felipe Ernesto; Muñoz Arango, Diana Carolina; Canales, Camila Pía; Hevia, Samuel A.; Leyton Soto, Felipe Arturo; Veloso Cid, Nicolás Eduardo; Isaacs Casanova, Mauricio; Vargas Cucurella, Ignacio Tomás; CEDEUS (Chile)
    Perchlorate has been described as an emerging pollutant that compromises water sources and human health. In this study, a new electrotrophic perchlorate reducing microorganism (EPRM) isolated from the Atacama Desert, Dechloromonas sp. CS-1, was evaluated for perchlorate removal in water in a bioelectrochemical reactor (BER) with a chemically modified electrode. BERs were operated for 17 days under batch mode conditions with an applied potential of −500 mV vs. Ag/AgCl. Surface analysis (i.e., SEM, XPS, FT-IR, RAMAN spectroscopy) on the modified electrode demonstrated heterogeneous transformation of the carbon fibers with the incorporation of nitrogen functional groups and the oxidation of the carbonaceous material. The BERs with the modified electrode and the presence of the EAM reached high cathodic efficiency (90.79 ± 9.157%) and removal rate (0.34 ± 0.007 mol m−3-day) compared with both control conditions. The observed catalytic enhancement of CS-1 was confirmed by a reduction in the charge transfer resistance obtained by electrochemical impedance spectroscopy (EIS). Finally, an electrochemical kinetic study revealed an eight-electron perchlorate bioreduction reaction at −638.33 ± 24.132 mV vs. Ag/AgCl. Therefore, our results show the synergistic effect of EPRM and chemically modified electrodes on perchlorate removal in a BER.