GALLEGOS CASTRO, ELVIA DEL CARMEN

Preferred name

Main Affiliation

Facultad de Ciencias, Ingeniería y Construcción

ORCID

0000-0002-0650-5750

Scopus Author ID

57219383093

Now showing 1 - 5 of 5

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Triclosan removal from synthetic solution using corn cobs and their magnetic composites: Insights from batch adsorption and fixed-bed column studies
(Elsevier BV, 2025-06-01)
Cristina E. Almeida Naranjo
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Fabián Santana-Romo
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GALLEGOS CASTRO, ELVIA DEL CARMEN
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Cristina Alejandra Villamar Ayala
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Debut, Alexis
Triclosan, a lipophilic contaminant and endocrine disruptor, is widely detected in industrial, pharmaceutical, and domestic wastewaters. Organic residues impregnated with nanoparticles could be efficient adsorbents for such contaminants. This study evaluated the efficiency of corn cobs (CC), iron oxide (IO), and their magnetic composites in removing triclosan (30 mg L−1) using batch and fixed-bed column tests. Adsorbents were characterized by analytical (ASTM standards), instrumental (microscopy, spectroscopy, BET, X-ray diffraction), and computational methods. Batch tests analyzed CC/IO/composite doses (0.001–2.5 g L−1), contact times (2.5–60 min), and CC ratios (1:1, 2:1, 4:1). Results fit kinetic and isothermal models. Fixed-bed columns used CC and 4CC:1IO (most efficient). CC contained ∼94.2 % lignocellulosic material, an irregular surface with 0.4 m² g−1, and functional groups (OH, C[dbnd]O, C-O-H). IOs (∼15 nm) had a surface area of 66.3 m²/g, while composites ranged from 1.4 to 2.2 m² g−1. Optimal doses were 2.0 g L−1 for CC and 3.75–25-fold for IO/composites, removing 84.7–94.1 % triclosan within 40–60 min. Data fit the pseudo-second order model (R² = 0.89–0.99) and isotherms aligned with Langmuir and Sips models (R² = 0.97–0.99). In fixed-bed columns, CC and 4CC:1IO reached saturation at 700 and 1250 min, respectively, fitting the Bohart-Adams model (R² = 0.93–0.98). Computational chemistry elucidated triclosan removal mechanisms related to its lipophilicity, solubility, and reactive lignocellulosic sites. CC and their composites are effective, sustainable, and low-cost alternatives for removing triclosan and other lipophilic emerging contaminants, with potential for broader water treatment applications. This study evaluated the adsorption capacity of the materials for triclosan removal, incorporating kinetic models, breakthrough curves, and computational simulations to understand the removal mechanisms.
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From Renewable Biomass to Water Purification Systems: Oil Palm Empty Fruit Bunch as Bio-Adsorbent for Domestic Wastewater Remediation and Methylene Blue Removal
(MDPI AG, 2023-11-28)
Cristina E. Almeida-Naranjo
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GALLEGOS CASTRO, ELVIA DEL CARMEN
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Elizabeth Domínguez
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Paola Gutiérrez
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Vladimir Valle
<jats:p>Oil palm empty fruit bunch fibers (OPEFBF), in three size ranges (small: 250–450 µm, medium: 450–600 µm, large: 600–800 µm), were investigated as a filter-bed material in biofilters for the removal of organic matter and nutrients. After saturation, these fibers (post) were used in the removal of methylene blue through batch processes. The batch adsorption tests included optimizing the adsorbent dosage (0.5–32.0 g/L) and contact time (2.5–60.0 min). Experimental data were fitted to various kinetic/isotherm models. Instrumental characterization of both raw and post fibers was conducted. Post fibers underwent morphological/compositional changes due to the presence of microorganisms and their byproducts. Efficiencies reached up to 94% for chemical oxygen demand (COD), 88.4% for total nitrogen and 77.2% for total phosphorus. In batch adsorption, methylene blue removal exceeded 90%, underscoring the effectiveness of small raw OPEFBF and large post OPEFBF. Kinetic models indicated that raw OPEFBF better fit the pseudo-first-order model, while post OPEFBF better fit the pseudo-second-order model. Both types of OPEFBF showed a good fit with the Freundlich model (higher R2, lower χ2 and SSE). Particularly, large post OPEFBF stood out as the most efficient adsorbent, achieving a maximum adsorption capacity of 12.02 mg/g for methylene blue. Therefore, raw/post OPEFBF could be an alternative to remove contaminants from wastewater.</jats:p>
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Pineapple-crown papers with partial NaOH substitution: Performance, costs, and life-cycle footprints
(Elsevier BV, 2026-02)
Ginger Capa
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Cinthia González
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GALLEGOS CASTRO, ELVIA DEL CARMEN
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Patricia Alba
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Edwin Vera
Non-wood agro-residues can reduce the environmental and cost burdens of papermaking, yet process alkalinity often drives impacts. Pineapple crowns were valorized as fiber feedstock and evaluated partial substitution of NaOH with NaHCO3 during processing, using NaOH–NaHCO3 ratios of 1:0, 3:1, and 1:1 (P100:0, P75:25, P50:50). Physical (grammage, thickness, porosity, burst, pH, water uptake) and instrumental characterizations, including Fourier-transform infrared spectroscopy (FTIR), thermogravimetric and derivative thermogravimetric analysis (TGA/DTGA), and scanning electron microscopy (SEM), were coupled with cradle-to-gate life-cycle (CF: carbon footprint; WF: water footprint) and unit-cost analyses. P75:25 achieved the highest grammage (71.86 ± 0.49 g/m2) and balanced network consolidation, while P100:0 maximized burst (19.53 ± 0.91 psi); P50:50 increased porosity and moisture uptake. TGA/DTGA indicated effective polysaccharide/lignin breakdown for P100:0 and P75:25, with elevated high-temperature residue in P50:50, aligning with SEM-resolved fiber compaction. Environmental results decreased monotonically with sodium-bicarbonate substitution: total CF = 0.25, 0.22 (−12 %), and 0.19 kg CO2-eq for P100:0, P75:25, and P50:50. WF per sheet was 6.56, 3.72, and 3.28 L for P100:0, P75:25, and P50:50, respectively. Despite lab-scale costs (≈4.0 USD/sheet), sensitivity indicates reagent price and electricity as main levers. Overall, P75:25 offers the best performance-to-impact trade-off preserving mechanical integrity while lowering CF and WF vs P100:0 supporting pineapple-crown papers as credible candidates for lightweight packaging and printing.
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Cellular concrete: A viable low‐carbon alternative for developing countries in seismic regions?
(Wiley, 2025-02-05)
Estefani Coral
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ÁVILA VEGA, CARLOS FABIÁN
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GALLEGOS CASTRO, ELVIA DEL CARMEN
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Andrés Salazar
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Liliana Barros
<jats:title>Abstract</jats:title><jats:p>This study investigates the potential of cellular concrete as an environmentally friendly alternative for shear walls based structural systems in seismic‐prone areas. The construction industry significantly contributes to global energy consumption and carbon emissions, mainly through the use of conventional materials like concrete and steel. In seismic regions, the challenge is to build structures that are both sustainable and earthquake resistant. Through a “cradle‐to‐gate” life cycle assessment (LCA), the study analyses the environmental impact of constructing a seven‐story archetype residential building in Quito‐Ecuador. The research reveals that steel reinforcement is the primary source of CO<jats:sub>2</jats:sub> emissions and energy consumption. Cellular concrete demonstrates a notable reduction in CO<jats:sub>2</jats:sub> emissions compared with traditional concrete, emphasizing the potential of cellular concrete as a low‐carbon alternative. The findings underscore the need to integrate LCA into structural design to minimize ecological impact. While promising for developing cities, further research is essential to inform sustainable construction practices without compromising safety in seismic zones.</jats:p>
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The Removal of Acidic Drugs from Domestic Wastewater Using an Innovative System of Constructed Wetlands/Stabilization Ponds in Series
(MDPI AG, 2025-04-16)
GALLEGOS CASTRO, ELVIA DEL CARMEN
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Cristina E. Almeida-Naranjo
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Armando Rivas
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Nancy Figueroa
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Leticia Montellano
Nature-based solutions represent a decentralized wastewater treatment proposal, offering diverse mechanisms for effectively removing emerging contaminants, particularly acidic pharmaceuticals. This study evaluated the performance of acidic-drug (diclofenac, fenofibrate, ibuprofen, gemfibrozil, fenoprofen, naproxen, and indomethacin) removal from wastewater using a surface-flow constructed wetland with an organic bed (Eichhornia crassipes (Mart.) Solms, 18 ind/m2), and a horizontal subsurface-flow constructed wetland, divided into three sections. The process was complemented by two stabilization ponds and other horizontal subsurface-flow wetlands using papyrus (Cyperus papyrus L., 8–13 ind/m2) and tezontle as support media. The industrial-scale system (67.8 m2) was fed with wastewater at a rate of 1.33 m3/d with a hydraulic time retention of about 5.8 days. Drugs were quantified by gas chromatography. The results showed that gemfibrozil and indomethacin were completely removed (100%), while diclofenac (73%) and naproxen (94%) showed significant removals. Fenoprofen was not removed. Ibuprofen and fenofibrate showed increased concentrations, resulting in negative removals due to anoxic conditions (ibuprofen) and a slightly neutral pH (fenofibrate). These findings underscore the system’s ability to improve water quality by removing most acidic drugs, suggesting that the hybrid design is particularly effective in treating specific wastewater contaminants.

GALLEGOS CASTRO, ELVIA DEL CARMEN

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