José Antonio Villanueva Salas

In the present research, Zea mays stem (ZMS) agricultural waste and its corresponding activated carbon (AC-ZMS) were successfully utilized as alternative low-cost adsorbents for the removal of Acid Green 25 (AG25), a highly resilient and toxic contaminant textile dye. The evaluation was systematically conducted using synthetic wastewater precisely prepared in the laboratory by dissolving the commercial analytical-grade dye in distilled water to eliminate external chemical interference. The ZMS powder exhibited a fibrillar morphology characteristic of lignocellulosic materials, and AC-ZMS a porous morphology. The removal experiments showed that at an initial concentration of 50 mg/L, pH = 2, an adsorbent dose of 20 g/L, and 20 °C, both materials reached equilibrium in 30 min, achieving removal efficiencies of 87.57% (ZMS) and 91.43% (AC-ZMS). The equilibrium data were fitted to the Langmuir isotherm model, resulting in maximum adsorption capacities (q_mL) that increased with temperature, reaching maximum values of 12.61 mg/g for ZMS and 13.56 mg/g for AC-ZMS at 40 °C. Thermodynamic and mechanism analyses justified the process of preparing AC-ZMS from ZMS for the removal of AG25, since ZMS powder would exhibit predominantly weak and reversible physical adsorption (ΔH⁰ = 15.94 kJ/mol), driven by pH-sensitive electrostatic attraction; in contrast, the adsorption of AG25 onto AC-ZMS is consistent with a chemisorption regime (ΔH⁰ = 86.64 kJ/mol). This change would prevent the degradation of active sites, allowing AC-ZMS to retain a remarkable 80.66% of its initial capacity after 5 consecutive regeneration cycles, whereas untreated ZMS suffers a severe drop in performance to 49.25%. The theoretical study demonstrated that the defect and oxygenated sites present in AC-ZMS attract and immobilize AG25, which causes it to be efficiently removed from synthetic solutions. In conclusion, AC-ZMS is a promising adsorbent in synthetic solutions; further work needed for real wastewater and reuse.

Introduction: The increasing population, water scarcity, and resource limitations challenge sanitation management, especially in developing countries. Traditional wastewater treatments, like flush toilets and chemically treated portable toilets, have drawbacks such as high energy consumption and odor issues. Lactic acid fermentation using Lactobacillus spp. presents a cost-effective, sustainable alternative by lowering pH and inhibiting pathogens. This study evaluated the effect of Lactobacillus casei fermentation on simulated fecal matter for potential use in fishing vessels, rural areas, and resource-limited settings. Methods: L. casei exhibited exponential growth up to 8 hours before stabilizing, with reduced proliferation at ambient temperature. Simulated fecal matter was prepared with microcrystalline cellulose, psyllium husk, oleic acid, mineral salts, soybean flour, and 15% molasses to enhance lactic acid production. Experiments were conducted using simulated feces compared to human feces, evaluating pH, microbial concentration, and physicochemical parameters. Results: Fermentation with L. casei (10% and 20%) reduced pH to approximately 4.0 within six days, remaining stable until day 30. Lactic acid production followed a similar trend, while Escherichia coli concentrations (initially 2.55×107 CFU/g) significantly decreased, with maximum reduction by day six. Comparable effectiveness between 10% and 20% L. casei suggests reduced inoculum concentrations may suffice for microbial control. Conclusion: These findings support L. casei fermentation as a promising biotechnological approach for pathogen reduction in waste treatment. The potential application of this method in portable sanitation systems, especially in rural areas with limited resources, is highlighted, contributing to sustainable waste management and pathogen control.

The use of organophosphate pesticides, such as profenofos, is a pressing environmental concern due to their persistence and toxicity to non-target organisms. For this reason, developing alternatives to remove them from the environment is crucial. The objective of this study was to biosynthesize ZnO nanoparticles (ZnO NPs) using an aqueous extract of Negra Criolla grape seeds for their application in the degradation of profenofos in synthetic solutions. The biosynthesized ZnO NPs had an average size of 52 ± 2 nm and a maximum absorption at 375 nm, characteristic of the surface plasmon resonance of ZnO NPs. The ATR-FTIR spectra showed peaks characteristic of ZnO NPs. The 2² × 3 factorial design showed that the optimal values for pH and ZnO NPs concentration are 5 and 3 g/L, respectively, achieving a primary degradation of profenofos (20 mg/L) of 59 ± 2% after 120 min of UV irradiation. In conclusion, it was demonstrated that ZnO NPs biosynthesized using an aqueous extract of Negra Criolla grape seeds exhibit photocatalytic activity for the degradation of profenofos; however, further studies are needed to evaluate their application in actual contaminated water.

Textile wastewater pollution is a global issue that requires attention due to its potential negative environmental impacts. Therefore, in the present investigation, Inga feuilleei seed (IFS) powder was used as a potential adsorbent of Direct Red 80 (DR80) dye in synthetic water. The results showed that the highest removal efficiency was achieved at pH = 2 and an IFS powder particle size of 150 μm. ART-FTIR analysis of IFS dust showed the presence of -OH, C=C, and C-H groups. The kinetic study revealed a better fit of the experimental adsorption data to the pseudo-second-order kinetics, suggesting that the mechanism governing the adsorption process is chemisorption. The maximum adsorption capacity of DR80 on IFS powder was 133.11, 146.78, 152.78, and 183.51 mg/g at 20, 30, 40, and 50 °C, respectively. According to the thermodynamic study, the process is endothermic and spontaneous. Finally, the use of IFS powder is a cost-effective alternative since the project approach for the development of the production process of this adsorbent is feasible and profitable. In conclusion, IFS powder is a cost-effective adsorbent for removing DR80 in water, and the process could be scaled up in removal studies on textile wastewater.

Eye shadows are cosmetic products widely used to enhance appearance. However, the use of raw materials contaminated with heavy metals poses potential health hazards. This study characterized 12 commercial eye shadow samples and quantified concentrations of Al, Ba, B, Cu, Cr, Fe, Mn, Ni, Pb, V, and Zn using inductively coupled plasma mass spectrometry (ICP-MS). Additional characterization using UV-vis, ATR-FTIR, and SEM-EDS techniques provided insights into the composition and potential sources of contamination. Multivariate analysis revealed differences in metal concentrations across brands. Health risk assessments, including margin of safety (MoS), hazard quotient (HQ), hazard index (HI), lifetime cancer risk (LCR), and lifetime cancer risk based on the long-term relevant daily systemic exposure dose (LCR′), indicated that one product may pose significant health risks. Specifically, sample M4 showed an HI of 2.67 × 10¹, exceeding acceptable limits. These findings highlight the need for stricter regulation and continuous monitoring of heavy metals in cosmetics to safeguard consumer health.

Aluminum is the third most abundant metal on earth and is currently widely used in industrial, technological and medical sectors, including pharmaceuticals and personal care products. However, in recent years, several studies suggest possible health risks of aluminum, being associated with neurotoxicity, Alzheimer's disease and breast cancer. Therefore, the aim of this study was to propose, develop and validate a simple, reliable and accessible UV-VIS spectrophotometric method for the quantification of aluminum by means of the aluminum-alizarin complex. The method proved to be linear with a coefficient of determination R 2 of 0.9998, precise with a relative standard deviation (RSD) of less than 11% and accurate with recovery percentages higher than 80% and lower than 110%, as stipulated by the AOAC. In conclusion, the method proved to be simple, accessible, reliable, precise and accurate for the quantification of aluminum in antiperspirant samples.

Breast cancer is the most common malignancy and one of the leading causes of death in women worldwide. Breast cells grow uncontrollably, forming tumors that can spread through the blood or lymphatic system. The treatment of breast cancer includes surgery, radiotherapy and the use of drugs such as doxorubicin, which aim to reduce the size of the tumor and improve the patient's condition. However, their efficacy is limited due to factors such as cellular resistance and efflux transporter activity. The aim of the work was to analyze the expression of NF-kB, Bcl-2 and Bax in MCF-7 and MDA-MB-231 breast cancer cell lines treated with doxorubicin (DOX). IC50 analysis of DOX was performed by MTT assay, gene quantification was by qPCR and In silico analysis of TLR4 and DOX was performed. MTT results showed that the IC50 for MCF-7 and MDA-MB-231 were 0.1µM and 0.3µM respectively. The qPCR results showed that the overexpression of NF-κB was 1.825±0.054 and 10.85±1.000 in MDA-MB-231 and MCF-7 cell lines respectively. For Bax, the expression level was 1.827±0.1036 and 0.6869±0.092 in MDA-MB-231 and MCF-7 cell line consecutively. Furthermore, In silico analysis showed that DOX docks into the extracellular domain cavity of TLR4 through interactions with Lys52 and Ile65A residues.

Arsenate As(V) is a toxic contaminant commonly found in aquifers and groundwater that poses significant risks to human health. The effective treatment of arsenic-contaminated water is therefore crucial for safeguarding public health. This study investigates removing As(V) using iron oxide-coated ignimbrite in batch experiments by varying the adsorbent dosage, initial As(V) concentration, contact time, and system temperature. The adsorption experiments revealed that the Langmuir isotherm model better fit the data (R² = 0.99) than the Freundlich model (R² = 0.73). According to the Langmuir model, the maximum adsorption capacity of As(V) on the iron oxide-coated ignimbrite was 4.84 mg·g⁻¹ ± 0.12 mg·g⁻¹ of As(V), with a standard deviation of ±0.05 mg·g⁻¹ after 2 h of exposure with 0.15 g/50 mL iron oxide-coated ignimbrite adsorbent concentration. In the kinetic analysis, the pseudo-first-order model best described the adsorption process at 283 K, 293 K, and 303 K, although the pseudo-second-order model also showed an adequate fit, particularly at 293 K. This indicates that, while the pseudo-first-order model is generally more suitable under these conditions, the pseudo-second-order model may also apply under certain circumstances. The results of the batch experiments demonstrate that iron oxide-coated ignimbrite is a promising adsorbent for effectively reducing high concentrations of As(V) in contaminated water.

Arsenate As (V) is a toxic aquifer/underground water element with a high potential to harm humans. Adequate treatment of arsenic-contaminated water is vital to ensure public health. The present investigation describes As (V) removal by iron oxide-coated in batch experiments at dif-ferent levels of adsorbent amount, contaminated solution initial concentration, contact time, and system temperature. Different As (V) initial concentrations showed that adsorption in the Langmuir isotherm model has a higher correlation coefficient (R2 = 0.99) than the Freundlich model (R2 = 0.73). According to the Langmuir model, the maximum adsorption capacity was 4.84 mg∙g-1 of As (V) after 2 h exposure with 0.15 g/50 mL iron oxide coated ignimbrite adsorbent concentration. Likewise, a pseudo-first-order model kinetic study was more adequate in de-scribing the adsorption process at As (V) concentration of 15 mg∙g-1 by using 0.15 g / 50 mL ad-sorbent concentration at 283 K, 293 K, and 303 K. Observed results in the batch experiments in-dicate that iron oxide-coated ignimbrite is a potential adsorbent for reducing high concentrations of As (V) in contaminated water.