Mapping high-risk areas for Mycobacterium tuberculosis complex bacteria transmission: Linking host space use and environmental contamination.

In many Mediterranean ecosystems, animal tuberculosis (TB), caused by Mycobacterium bovis, an ecovar of Mycobacterium tuberculosis complex (MTBC), is maintained by multi-host communities. It is hypothesised that interspecies transmission is mainly indirect via shared contaminated environments. Therefore, identifying spatial areas where MTBC bacteria occur and quantifying space use by susceptible hosts might help predict the spatial likelihood of transmission across the landscape. Here, we aimed to evaluate the transmission risk of MTBC in a multi-host system involving wildlife (ungulates and carnivores) and cattle (Bos taurus). We collected eighty-nine samples from natural substrates (water, soil, and mud) at 38 sampling sites in a TB endemic area within a Mediterranean agroforestry system in Portugal. These samples were analysed by real-time PCR to detect MTBC DNA. Additionally, host-specific space use intensity maps were obtained through camera-trapping covering the same sampling sites. Results evidenced that a significant proportion of samples were positive for MTBC DNA (49 %), suggesting that the contamination is widespread in the area. Moreover, they showed that the probability of MTBC occurrence in the environment was significantly influenced by topographic features (i.e., slope), although other non-significant predictor related with soil conditions (SMI: soil moisture index) incorporated the MTBC contamination model. The integration of host space use intensity maps with the spatial detection of MTBC showed that the red deer (Cervus elaphus) and wild boar (Sus scrofa) exhibited the highest percentages of high-risk areas for MTBC transmission. Furthermore, when considering the co-occurrence of multiple hosts, transmission risk analyses revealed that 26.5 % of the study area represented high-risk conditions for MTBC transmission, mainly in forest areas.

Skin Aging and the Upcoming Role of Ferroptosis in Geroscience.

The skin is considered the most important organ system in mammals, and as the population ages, it is important to consider skin aging and anti-aging therapeutic strategies. Exposure of the skin to various insults induces significant changes throughout our lives, differentiating the skin of a young adult from that of an older adult. These changes are caused by a combination of intrinsic and extrinsic aging. We report the interactions between skin aging and its metabolism, showing that the network is due to several factors. For example, iron is an important nutrient for humans, but its level increases with aging, inducing deleterious effects on cellular functions. Recently, it was discovered that ferroptosis, or iron-dependent cell death, is linked to aging and skin diseases. The pursuit of new molecular targets for ferroptosis has recently attracted attention. Prevention of ferroptosis is an effective therapeutic strategy for the treatment of diseases, especially in old age. However, the pathological and biological mechanisms underlying ferroptosis are still not fully understood, especially in skin diseases such as melanoma and autoimmune diseases. Only a few basic studies on regulated cell death exist, and the challenge is to turn the studies into clinical applications.

Advances in Tissue Culture and Transformation Studies in Non-model Species: Passiflora spp. (Passifloraceae).

In this chapter, we report advances in tissue culture applied to Passiflora. We present reproducible protocols for somatic embryogenesis, endosperm-derived triploid production, and genetic transformation for such species knowledge generated by our research team and collaborators in the last 20 years. Our research group has pioneered the work on passion fruit somatic embryogenesis, and we directed efforts to characterize several aspects of this morphogenic pathway. Furthermore, we expanded the possibilities of understanding the molecular mechanism related to developmental phase transitions of Passiflora edulis Sims. and P. cincinnata Mast., and a transformation protocol is presented for the overexpression of microRNA156.

[National health systems, legislation, and social determinants: a comparative study of Brazil, Spain, Portugal, and Italy]. / Sistemas nacionais de saúde, legislação e seus determinantes sociais: um estudo comparativo entre Brasil, Espanha, Portugal e Itália.

This is a documentary, exploratory, descriptive study, which is part of a multicenter international study assessing the national health systems with a care model based on primary health care of Brazil, Spain, Italy, and Portugal, funded by the Brazilian National Research Council (CNPq, acronym in Portuguese). It aims to identify the basic health legislation, the right to health, and the doctrinal and organizational principles of each country with a focus on the impact of social determinants of health on the national health systems. The results showed these countries have similar legislation and doctrinal principles, with a constitutional right to health, based on primary health care, and with a care model of the family health type. The challenges identified were low birth rate and high life expectancy at birth in European countries and criteria for access to medication and care financing. Based on our findings, the countries with higher investment in a structural basis, ensuring more dignified, solid, and vigilant socioeconomic and sanitary conditions, provide an important differentiation in responsiveness and sustainability of the national health system and direct impact on the quality of life.

Trata-se de uma pesquisa documental, exploratória, descritiva, partindo de um estudo multicêntrico e internacional entre Brasil, Espanha, Itália e Portugal sobre sistemas nacionais de saúde com modelo de atenção baseado na atenção primária à saúde e financiado pelo Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) do Brasil. Tem como objetivo identificar as legislações de base da saúde, o direito à saúde e os princípios doutrinários e organizativos de cada país selecionado com ênfase no impacto dos determinantes sociais de saúde sobre os sistemas nacionais de saúde. Os resultados revelaram países com legislações e princípios doutrinários semelhantes, com direito à saúde constitucional, ancorados na atenção primária à saúde, e com modelo assistencial de acesso do tipo saúde da família. Os desafios encontrados foram a baixa natalidade e elevada expectativa de vida ao nascer em países europeus e critérios para acesso a medicamentos e financiamento assistencial. Com base nos nossos achados, os países que tiveram maior investimento em base estrutural, perpassando por assegurar condições socioeconômicas e sanitárias mais dignas, sólidas e vigilantes, garantiram importante diferenciação na capacidade de resposta e sustentabilidade do sistema nacional de saúde e no impacto direto na qualidade de vida das pessoas.

Se trata de una investigación documental, exploratoria, descriptiva, parte de un estudio multicéntrico, internacional entre Brasil, España, Italia y Portugal sobre los Sistemas Nacionales de Salud con un modelo de atención basado en la atención primaria de salud y financiado por el Consejo Nacional de Desarrollo Científico y Tecnológico (CNPq) de Brasil. Tiene como objetivo identificar la legislación de base de la salud, el derecho a la salud y los principios doctrinales y organizativos de cada país seleccionado con énfasis en el impacto de los determinantes sociales de la salud sobre los sistemas nacionales de salud. Los resultados revelaron países con legislaciones y principios doctrinales similares, con derecho a salud constitucional, anclados en la atención primaria de salud y con un modelo asistencial de acceso del tipo salud de la familia. Los desafíos encontrados fueron la baja tasa de natalidad y la alta esperanza de vida al nacer en países europeos y criterios para el acceso a medicamentos y financiación asistencial. Con base en nuestros hallazgos, los países que tuvieron mayor inversión en base estructural, asegurando condiciones socioeconómicas y sanitarias más dignas, sólidas y vigilantes, garantizan una diferenciación importante en la capacidad de respuesta y sostenibilidad del sistema nacional de salud y en el impacto directo en la calidad de vida de las personas.

First time whole genome sequencing of Mycobacterium bovis from the environment supports transmission at the animal-environment interface.

Spreading of Mycobacterium bovis causing animal tuberculosis (TB) at livestock-wildlife-environment interfaces remains a significant problem. Recently, we provided evidence of widespread environmental contamination of an endemic animal TB setting with viable and dormant M. bovis cells able to recover metabolic activity, making indirect transmission via environmental contamination plausible. We now report the first whole genome sequences of M. bovis recovered from the environment. We establish epidemiological links at the environment-animal interface by phylogenomic comparison of these M. bovis genomes with those isolated from livestock and wild ungulates from the same area. Environmental and animal genomes are highly intertwined and distribute similarly into the same M. bovis lineages, supporting several instances of environmental contamination. This study provides compelling evidence of M. bovis excretion into the environment and viability maintenance, supporting the environment as a potential source of new infection. These insights have clear implications for policy formulation, advocating environmental surveillance and an ecosystem perspective in TB control programs. ENVIRONMENTAL IMPLICATION: We report the first whole genome sequences of M. bovis from the environment and establish epidemiological links at the environment-animal interface, demonstrating close phylogenomic relatedness of animal and environmental M. bovis. Definitive evidence of M. bovis excretion into the environment with viability maintenance is provided, supporting the environment as a potential source of new infection. Implications of this work include methodological innovations offering a tool to resolve indirect transmission chains and support customized biosecurity measures. Policy formulation aiming at the control of animal tuberculosis and cost mitigation should consider these findings, encouraging environmental surveillance in official eradication programmes.

Rescue of Mycobacterium bovis DNA Obtained from Cultured Samples during Official Surveillance of Animal TB: Key Steps for Robust Whole Genome Sequence Data Generation.

Epidemiological surveillance of animal tuberculosis (TB) based on whole genome sequencing (WGS) of Mycobacterium bovis has recently gained track due to its high resolution to identify infection sources, characterize the pathogen population structure, and facilitate contact tracing. However, the workflow from bacterial isolation to sequence data analysis has several technical challenges that may severely impact the power to understand the epidemiological scenario and inform outbreak response. While trying to use archived DNA from cultured samples obtained during routine official surveillance of animal TB in Portugal, we struggled against three major challenges: the low amount of M. bovis DNA obtained from routinely processed animal samples; the lack of purity of M. bovis DNA, i.e., high levels of contamination with DNA from other organisms; and the co-occurrence of more than one M. bovis strain per sample (within-host mixed infection). The loss of isolated genomes generates missed links in transmission chain reconstruction, hampering the biological and epidemiological interpretation of data as a whole. Upon identification of these challenges, we implemented an integrated solution framework based on whole genome amplification and a dedicated computational pipeline to minimize their effects and recover as many genomes as possible. With the approaches described herein, we were able to recover 62 out of 100 samples that would have otherwise been lost. Based on these results, we discuss adjustments that should be made in official and research laboratories to facilitate the sequential implementation of bacteriological culture, PCR, downstream genomics, and computational-based methods. All of this in a time frame supporting data-driven intervention.

Transient Receptor Potential Channels in the Healthy and Diseased Blood-Brain Barrier.

The large family of transient receptor potential (TRP) channels are integral membrane proteins that function as environmental sensors and act as ion channels after activation by mechanical (touch), physical (heat, pain), and chemical stimuli (pungent compounds such as capsaicin). Most TRP channels are localized in the plasma membrane of cells but some of them are localized in membranes of organelles and function as intracellular Ca2+-ion channels. TRP channels are involved in neurological disorders but their precise role(s) and relevance in these disorders are not clear. Endothelial cells of the blood-brain barrier (BBB) express TRP channels such as TRP vanilloid 1-4 and are involved in thermal detection by regulating BBB permeability. In neurological disorders, TRP channels in the BBB are responsible for edema formation in the brain. Therefore, drug design to modulate locally activity of TRP channels in the BBB is a hot topic. Today, the application of TRP channel antagonists against neurological disorders is still limited.

Exploring the Gut Microbiome and Metabolome in Individuals with Alopecia Areata Disease.

In recent years, heightened attention has been devoted to unravelling the intricate interplay between genetic and environmental factors shaping the gut microbiota and its significance for human health. This study delves into exploring the plausible connection between Alopecia Areata (AA), an autoimmune disease, and the dynamics of the gut microbiome. Examining a cohort of healthy adults and individuals with AA, both the gut microbiota composition and volatile organic compound (VOC) metabolites from faeces and urine were analysed. While overall microbiota composition showed no significant differences, intra-individual variability revealed distinctions related to age, gender, and pathology status, with AA individuals exhibiting reduced species richness and evenness. Differential abundance analysis identified microbial biomarkers for AA, notably Firmicutes, Lachnospirales, and Blautia, while Coprococcus stood out for healthy individuals. The Data Integration Analysis for Biomarker discovery using Latent Components (DIABLO) method further supported these findings including metabolite biomarkers, such as esters of branched chain fatty acids and branched chain amino acids as predictors for AA, suggesting potential links to oxidative stress. Despite certain limitations, the study highlights the complexity of the gut microbiome and its metabolites in the context of AA, while the biomarkers identified could be useful starting points for upcoming studies.

Relation Between Reactive Oxygen Species Production and Transient Receptor Potential Vanilloid1 Expression in Human Skin During Aging.

Skin sensitivity and impaired epidermal barrier function are associated with aging and are at least partly due to increased production of reactive oxygen species (ROS). Transient receptor potential vanilloid1 (TRPV1) is expressed in keratinocytes, fibroblasts, mast cells, and endothelial cells in skin. We investigated in skin biopsies of adult and elderly donors whether TRPV1 expression is involved in the skin aging process. We found that aging skin showed a strongly reduced epidermal thickness, strongly increased oxidative stress, protease expression, and mast cell degranulation and strongly increased TRPV1 expression both in epidermis and dermis. Based on our findings, the aging-related changes observed in the epidermis of the skin level are associated with increased ROS production, and hypothesized alterations in TRPV1 expression are mechanistically linked to this process.

Systematic SARS-CoV-2 S-gene sequencing in wastewater samples enables early lineage detection and uncovers rare mutations in Portugal.

As the COVID-19 pandemic reached its peak, many countries implemented genomic surveillance systems to track the evolution and transmission of SARS-CoV-2. Transition from the pandemic to the endemic phase prioritized alternative testing strategies to maintain effective epidemic surveillance at the population level, with less intensive sequencing efforts. One such promising approach was Wastewater-Based Surveillance (WBS), which offers non-invasive, cost-effective means for analysing virus trends at the sewershed level. From 2020 onwards, wastewater has been recognized as an instrumental source of information for public health, with national and international authorities exploring options to implement national wastewater surveillance systems and increasingly relying on WBS as early warning of potential pathogen outbreaks. In Portugal, several pioneer projects joined the academia, water utilities and Public Administration around WBS. To validate WBS as an effective genomic surveillance strategy, it is crucial to collect long term performance data. In this work, we present one year of systematic SARS-CoV-2 wastewater surveillance in Portugal, representing 35 % of the mainland population. We employed two complementary methods for lineage determination - allelic discrimination by RT-PCR and S-gene sequencing. This combination allowed us to monitor variant evolution in near-real-time and identify low-frequency mutations. Over the course of this year-long study, spanning from May 2022 to April 2023, we successfully tracked the dominant Omicron sub-lineages, their progression and evolution, which aligned with concurrent clinical surveillance data. Our results underscore the effectiveness of WBS as a tracking system for virus variants, with the ability to unveil mutations undetected via massive sequencing of clinical samples from Portugal, demonstrating the ability of WBS to uncover new mutations and detect rare genetic variants. Our findings emphasize that knowledge of the genetic diversity of SARS-CoV-2 at the population level can be extended far beyond via the combination of routine clinical genomic surveillance with wastewater sequencing and genotyping.

Neonatal Skull Depression: The Role of Cranial Ultrasound.

Nontraumatic congenital neonatal skull depression is a rare condition resulting from external forces shaping the fetal skull. Typically, newborns are asymptomatic, and, usually, the condition resolves in a few months with no need for intervention. However, many newborns undergo a CT scan, an ionizing technique, to check for fractures or intracranial lesions. We report a case of congenital skull depression without neurological deficits, managed conservatively through clinical monitoring and ultrasound.

Hepatic Alterations in a BTBR T + Itpr3tf/J Mouse Model of Autism and Improvement Using Melatonin via Mitigation Oxidative Stress, Inflammation and Ferroptosis.

Autism spectrum disorder (ASD) is a complicated neurodevelopmental disorder, and its etiology is not well understood. It is known that genetic and nongenetic factors determine alterations in several organs, such as the liver, in individuals with this disorder. The aims of the present study were to analyze morphological and biological alterations in the liver of an autistic mouse model, BTBR T + Itpr3tf/J (BTBR) mice, and to identify therapeutic strategies for alleviating hepatic impairments using melatonin administration. We studied hepatic cytoarchitecture, oxidative stress, inflammation and ferroptosis in BTBR mice and used C57BL6/J mice as healthy control subjects. The mice were divided into four groups and then treated and not treated with melatonin, respectively. BTBR mice showed (a) a retarded development of livers and (b) iron accumulation and elevated oxidative stress and inflammation. We demonstrated that the expression of ferroptosis markers, the transcription factor nuclear factor erythroid-related factor 2 (NFR2), was upregulated, and the Kelch-like ECH-associated protein 1 (KEAP1) was downregulated in BTBR mice. Then, we evaluated the effects of melatonin on the hepatic alterations of BTBR mice; melatonin has a positive effect on liver cytoarchitecture and metabolic functions.

Closed-loop parameter optimization for patient-specific phrenic nerve stimulation.

BACKGROUND: Ventilator-induced diaphragm dysfunction occurs rapidly following the onset of mechanical ventilation and has significant clinical consequences. Phrenic nerve stimulation has shown promise in maintaining diaphragm function by inducing diaphragm contractions. Non-invasive stimulation is an attractive option as it minimizes the procedural risks associated with invasive approaches. However, this method is limited by sensitivity to electrode position and inter-individual variability in stimulation thresholds. This makes clinical application challenging due to potentially time-consuming calibration processes to achieve reliable stimulation. METHODS: We applied non-invasive electrical stimulation to the phrenic nerve in the neck in healthy volunteers. A closed-loop system recorded the respiratory flow produced by stimulation and automatically adjusted the electrode position and stimulation amplitude based on the respiratory response. By iterating over electrodes, the optimal electrode was selected. A binary search method over stimulation amplitudes was then employed to determine an individualized stimulation threshold. Pulse trains above this threshold were delivered to produce diaphragm contraction. RESULTS: Nine healthy volunteers were recruited. Mean threshold stimulation amplitude was 36.17 ± 14.34 mA (range 19.38-59.06 mA). The threshold amplitude for reliable nerve capture was moderately correlated with BMI (Pearson's r = 0.66, p = 0.049). Repeating threshold measurements within subjects demonstrated low intra-subject variability of 2.15 ± 1.61 mA between maximum and minimum thresholds on repeated trials. Bilateral stimulation with individually optimized parameters generated reliable diaphragm contraction, resulting in significant inhaled volumes following stimulation. CONCLUSION: We demonstrate the feasibility of a system for automatic optimization of electrode position and stimulation parameters using a closed-loop system. This opens the possibility of easily deployable individualized stimulation in the intensive care setting to reduce ventilator-induced diaphragm dysfunction.

Sistemas nacionais de saúde, legislação e seus determinantes sociais: um estudo comparativo entre Brasil, Espanha, Portugal e Itália / National health systems, legislation, and social determinants: a comparative study of Brazil, Spain, Portugal, and Italy / Sistemas nacionales de salud, legislación y sus determinantes sociales: un estudio comparativo entre Brasil, España, Portugal e Italia

Resumo: Trata-se de uma pesquisa documental, exploratória, descritiva, partindo de um estudo multicêntrico e internacional entre Brasil, Espanha, Itália e Portugal sobre sistemas nacionais de saúde com modelo de atenção baseado na atenção primária à saúde e financiado pelo Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) do Brasil. Tem como objetivo identificar as legislações de base da saúde, o direito à saúde e os princípios doutrinários e organizativos de cada país selecionado com ênfase no impacto dos determinantes sociais de saúde sobre os sistemas nacionais de saúde. Os resultados revelaram países com legislações e princípios doutrinários semelhantes, com direito à saúde constitucional, ancorados na atenção primária à saúde, e com modelo assistencial de acesso do tipo saúde da família. Os desafios encontrados foram a baixa natalidade e elevada expectativa de vida ao nascer em países europeus e critérios para acesso a medicamentos e financiamento assistencial. Com base nos nossos achados, os países que tiveram maior investimento em base estrutural, perpassando por assegurar condições socioeconômicas e sanitárias mais dignas, sólidas e vigilantes, garantiram importante diferenciação na capacidade de resposta e sustentabilidade do sistema nacional de saúde e no impacto direto na qualidade de vida das pessoas.

Abstract: This is a documentary, exploratory, descriptive study, which is part of a multicenter international study assessing the national health systems with a care model based on primary health care of Brazil, Spain, Italy, and Portugal, funded by the Brazilian National Research Council (CNPq, acronym in Portuguese). It aims to identify the basic health legislation, the right to health, and the doctrinal and organizational principles of each country with a focus on the impact of social determinants of health on the national health systems. The results showed these countries have similar legislation and doctrinal principles, with a constitutional right to health, based on primary health care, and with a care model of the family health type. The challenges identified were low birth rate and high life expectancy at birth in European countries and criteria for access to medication and care financing. Based on our findings, the countries with higher investment in a structural basis, ensuring more dignified, solid, and vigilant socioeconomic and sanitary conditions, provide an important differentiation in responsiveness and sustainability of the national health system and direct impact on the quality of life.

Resumen: Se trata de una investigación documental, exploratoria, descriptiva, parte de un estudio multicéntrico, internacional entre Brasil, España, Italia y Portugal sobre los Sistemas Nacionales de Salud con un modelo de atención basado en la atención primaria de salud y financiado por el Consejo Nacional de Desarrollo Científico y Tecnológico (CNPq) de Brasil. Tiene como objetivo identificar la legislación de base de la salud, el derecho a la salud y los principios doctrinales y organizativos de cada país seleccionado con énfasis en el impacto de los determinantes sociales de la salud sobre los sistemas nacionales de salud. Los resultados revelaron países con legislaciones y principios doctrinales similares, con derecho a salud constitucional, anclados en la atención primaria de salud y con un modelo asistencial de acceso del tipo salud de la familia. Los desafíos encontrados fueron la baja tasa de natalidad y la alta esperanza de vida al nacer en países europeos y criterios para el acceso a medicamentos y financiación asistencial. Con base en nuestros hallazgos, los países que tuvieron mayor inversión en base estructural, asegurando condiciones socioeconómicas y sanitarias más dignas, sólidas y vigilantes, garantizan una diferenciación importante en la capacidad de respuesta y sostenibilidad del sistema nacional de salud y en el impacto directo en la calidad de vida de las personas.

The Menopausal Transition: Is the Hair Follicle "Going through Menopause"?

This article explores the link between menopause and changes in the hair follicle (HF) lifecycle, focusing on hormonal and metabolic dynamics. During menopause, hormonal fluctuations and aging can impact the HF, leading to phenomena such as thinning, loss of volume, and changes in hair texture. These changes are primarily attributed to a decrease in estrogen levels. However, not all women experience significant hair changes during menopause, and the extent of transformations can vary considerably from person to person, influenced by genetic factors, stress, diet, and other elements. Furthermore, menopause mirrors the aging process, affecting metabolism and blood flow to the HFs, influencing the availability of vital nutrients. The article also discusses the key role of energy metabolism in the HF lifecycle and the effect of hormones, particularly estrogens, on metabolic efficiency. The concept of a possible "menopause" clinically independent of menopause is introduced, related to changes in HF metabolism, emphasizing the importance of individual factors such as estrogen receptor responses, genetics, and last but not least, the microbiota in determining these dynamics.

Management of the human hair follicle microbiome by a synthetic odorant.

BACKGROUND: Human scalp hair follicles (HFs) engage in olfactory receptor (OR)-dependent chemosensation. Activation of olfactory receptor family 2 subfamily AT member 4 (OR2AT4) by the synthetic, sandalwood-like odorant Sandalore® up-regulated HF antimicrobial peptide expression of dermcidin (DCD), which had previously been thought to be produced exclusively by sweat and sebaceous glands. OBJECTIVES: To understand if intrafollicular DCD production can be stimulated by a commonly used cosmetic odorant, thus altering human HF microbiome composition in a clinically beneficial manner. METHODS: DCD expression was compared between fresh-frozen scalp biopsies and microdissected, full-length scalp HFs, organ-cultured in the presence/absence of the OR2AT4 agonist, Sandalore® and/or antibiotics and/or the competitive OR2AT4 antagonist, Phenirat®. Amplicon-based sequencing and microbial growth assays were performed to assess how this treatment affected the HF microbiome. RESULTS: Synthetic odorant treatment upregulated epithelial DCD expression and exerted antimicrobial activity in human HFs ex vivo. Combined antibiotic and odorant treatment, during an ex vivo dysbiosis event, prevented HF tissue damage and favoured a more physiological microbiome composition. Sandalore®-conditioned medium, containing higher DCD content, favoured Staphylococcus epidermidis and Malassezia restricta over S. aureus and M. globosa, while exhibiting antimicrobial activity against Cutibacterium acnes. These effects were reversed by co-administration of Phenirat®. CONCLUSIONS: We provide the first proof-of-principle that a cosmetic odorant impacts the human HF microbiome by up-regulating antimicrobial peptide production in an olfactory receptor-dependent manner. Specifically, a synthetic sandalwood-like odorant stimulates intrafollicular DCD production, likely via OR2AT4, and thereby controls microbial overgrowth. Thus, deserving further exploration as an adjuvant therapeutic principle in the management of folliculitis and dysbiosis-associated hair diseases.

Pollutants abatement in aqueous solutions with geopolymer catalysts: A photo fenton case.

Environmental pollution is a serious threat to human health and the natural environment, and it has aroused widespread concern. One of the most effective processes in the removal of pollutants from wastewater is the Fenton reaction. This process is based on the production of highly reactive •OH radicals due to the rapid reaction between Iron ions and hydrogen peroxide under acidic conditions. The hydroxyl radical has a high oxidation potential of E°(•OH/H2O) = 2.8 V/SHE at acidic pH, so they are extremely reactive and non-selective oxidizing agent towards organic contaminants in wastewater. In order to avoid the drawbacks of a standard Fenton reaction, a photo Fenton reaction has been tested working at neutral pH in water in the removal of refractory pollutants. For the first time, a heterogeneous system was experimented, impregnating porous metakaolin-based geopolymers, obtained by using hydrogen peroxide and vegetable oil in different ratios, as foaming agents, with iron working as photocatalyst. The dirty wastewater as scrubber water (SCRW) and liquid fraction of digestate (LFD) were tested obtaining 40-90% abatement of Total Carbon Content.