An Electroanalytical Solution for the Determination of Pb2+ in Progressive Hair Dyes Using the Cork–Graphite Sensor

open7Lead is one of the most toxic metals for living organisms: once absorbed by soft tissues, it is capable of triggering various pathologies, subsequently bioaccumulating in the bones. In consideration of this, its detection and quantification in products for human consumption and use is of great interest, especially if the procedure can be carried out in an easy, reproducible and economical way. This work presents the results of the electroanalytical determination of lead in three different commercial products used as progressive hair dyes. Analyses were performed by cyclic voltammetry (CV) and differential pulse stripping voltammetry (DPSV) using a composite cork–graphite sensor in 0.5M H2SO4 solution or 0.1M acetate buffer (pH 4.5), in the presence and absence of hair dye samples. The H2SO4 solution gave better results in terms of analyte sensitivity than the acetate buffer electrolyte. In both cases, well-defined signals for lead were obtained by DPSV analyses, enabling the calibration curve and figures of merit to be determined. The limits of detection (LOD) were found to be approximately 1.06 µM and 1.26 µM in H2SO4 and acetate buffer, respectively. The DPSV standard addition method was successfully applied to quantify the lead in hair dye samples, yielding values below 0.45% in Pb. All three analyzed samples were shown to comply with the limit set by the Brazilian Health Regulatory Agency, i.e., 0.6% lead in this type of product. The comparison of the electroanalytical results with those obtained by the reference method, based on the use of inductively coupled plasma optical emission spectrometry (ICP–OES), confirmed that the electroanalytical detection approach is potentially applicable as a strategy for quality control.openBarros, Thalita Medeiros; Medeiros de Araújo, Danyelle Medeiros de; Lemos de Melo, Alana Tamires Lemos de; Martínez-Huitle, Carlos Alberto; Vocciante, Marco; Ferro, Sergio; Vieira dos Santos, Elisama Vieira dosBarros, Thalita Medeiros; Medeiros de Araújo, Danyelle Medeiros de; Lemos de Melo, Alana Tamires Lemos de; Martínez-Huitle, Carlos Alberto; Vocciante, Marco; Ferro, Sergio; Vieira dos Santos, Elisama Vieira do

Electrochemical conversion/combustion of a model organic pollutant on BDD anode: Role of sp3/sp2 ratio

In this work, it is presented critical evidence about the influence of sp3/sp2 ratio on the performance of electrochemical oxidation (combustion or conversion) of Rhodamine B (RhB), used as a model organic pollutant. Results demonstrate that the higher the content in diamond-carbon, the greater are the TOC and COD decay rates and hence the oxidation of organic to CO2. The evidence of chromatographic analysis also indicates that the oxidation carried out by the diamonds with lower content of sp3-carbon is softer, favoring electrochemical conversion of RhB instead of mineralization. This degradation pathway is followed because higher graphite content on BDD anode leads to a higher direct electrochemical activity. These results are of a paramount significance for the choice of electrodes that could guarantee high efficiencies in wastewater remediation processes; because they clearly indicate that the sp3-sp2 carbon ratio should be kept as higher as possible in order to deplete completely pollutants and intermediates from the waste

Pressurized electro-Fenton for the reduction of the environmental impact of antibiotics

This work evaluates the performance of a pressurized heterogeneous electro-Fenton (EF) process to transform the antibiotic into compounds that do not promote the appearance of bacteria resistant to antibiotic in the environment. Experimental system consisted of a pressurized non divided microfluidic electrochemical cell equipped with a jet aerator, flow-through electrodes and a fluidized bed of goethite as heterogeneous iron catalyst. Results show that meropenem (model antibiotic) can be degraded by EF and that the degradation rate depends on the gauge pressure applied: the higher is the pressurization, the faster is the abatement of meropenem. The antibiotic effect of the urine is related to meropenem remained in the treated urine, and the contribution of reaction intermediates does not seem to be relevant. The mineralization of the organic load is almost nil. The higher dissolved oxygen concentration of pressurized-EF and thus, the higher hydrogen peroxide generation seems to be the key point to explain the effect of pressure on EF process. Results confirm that moderated pressurized EF process (up to 3 bar) can be satisfactorily used to decrease the chemical risk of synthetic hospital urines, which opens the possibility of an optimized pre-treatment which may help to save cost in the treatment of these hazardous wastes.This work evaluates the performance of a pressurized heterogeneous electro-Fenton (EF) process to transform the antibiotic into compounds that do not promote the appearance of bacteria resistant to antibiotic in the environment. Experimental system consisted of a pressurized non divided microfluidic electrochemical cell equipped with a jet aerator, flow-through electrodes and a fluidized bed of goethite as heterogeneous iron catalyst. Results show that meropenem (model antibiotic) can be degraded by EF and that the degradation rate depends on the gauge pressure applied: the higher is the pressurization, the faster is the abatement of meropenem. The antibiotic effect of the urine is related to meropenem remained in the treated urine, and the contribution of reaction intermediates does not seem to be relevant. The mineralization of the organic load is almost nil. The higher dissolved oxygen concentration of pressurized-EF and thus, the higher hydrogen peroxide generation seems to be the key point to explain the effect of pressure on EF process. Results confirm that moderated pressurized EF process (up to 3 bar) can be satisfactorily used to decrease the chemical risk of synthetic hospital urines, which opens the possibility of an optimized pre-treatment which may help to save cost in the treatment of these hazardous wastes

Activation by light irradiation of oxidants electrochemically generated during Rhodamine B elimination

In this work, the role of chloro-species generated during the electrolysis of Rhodamine B (RhB) solutions containing chloride and perchlorate salts as supporting electrolytes was studied. Likewise, the effect of light irradiation in the activation of the oxidants is also evaluated. To do this, essays of electrolysis, photoelectrolysis, and chemical oxidation in the presence of light with the oxidant generated electrochemically were carried out. Results showed that RhB was effectively oxidized by electro-irradiated techniques. Color removal is faster than chemical oxygen demand (COD) and total organic carbon (TOC) removal, due to the rapid attack of chromophore group of the molecule. In general, light irradiation has a positive effect during the electrolysis of RhB at high current densities. In chloride media, light irradiation seems to favor the decomposition of hypochlorite produced. The effect of light irradiation is explained in terms of the activation of oxidants in the bulk of the electrolytic treatment by production of highly efficient radicals. Results of chemical oxidation essays may indicate that UV light irradiation has not a clear catalytic influence out of an electrolytic environment. The findings presented in this communication are described and discussed in the light of the existing literature

Achieving Electrochemical-Sustainable-Based Solutions for Monitoring and Treating Hydroxychloroquine in Real Water Matrix

Hydroxychloroquine (HCQ) has been extensively consumed due to the Coronavirus (COVID-19) pandemic. Therefore, it is increasingly found in different water matrices. For this reason, the concentration of HCQ in water should be monitored and the treatment of contaminated water matrices with HCQ is a key issue to overcome immediately. Thus, in this study, the development of technologies and smart water solutions to reach the Sustainable Development Goal 6 (SDG6) is the main objective. To do that, the integration of electrochemical technologies for their environmental application on HCQ detection, quantification and degradation was performed. Firstly, an electrochemical cork-graphite sensor was prepared to identify/quantify HCQ in river water matrices by differential pulse voltammetric (DPV) method. Subsequently, an HCQ-polluted river water sample was electrochemically treated with BDD electrode by applying 15, 30 and 45 mA cm−2. The HCQ decay and organic matter removal was monitored by DPV with composite sensor and chemical oxygen demand (COD) measurements, respectively. Results clearly confirmed that, on the one hand, the cork-graphite sensor exhibited good current response to quantify of HCQ in the river water matrix, with limit of detection and quantification of 1.46 mg L−1 (≈3.36 µM) and 4.42 mg L−1 (≈10.19 µM), respectively. On the other hand, the electrochemical oxidation (EO) efficiently removed HCQ from real river water sample using BDD electrodes. Complete HCQ removal was achieved at all applied current densities; whereas in terms of COD, significant removals (68%, 71% and 84% at 15, 30 and 45 mA cm−2, respectively) were achieved. Based on the achieved results, the offline integration of electrochemical SDG6 technologies in order to monitor and remove HCQ is an efficient and effective strategy

Achieving Electrochemical-Sustainable-Based Solutions for Monitoring and Treating Hydroxychloroquine in Real Water Matrix

Hydroxychloroquine (HCQ) has been extensively consumed due to the Coronavirus (COVID-19) pandemic. Therefore, it is increasingly found in different water matrices. For this reason, the concentration of HCQ in water should be monitored and the treatment of contaminated water matrices with HCQ is a key issue to overcome immediately. Thus, in this study, the development of technologies and smart water solutions to reach the Sustainable Development Goal 6 (SDG6) is the main objective. To do that, the integration of electrochemical technologies for their environmental application on HCQ detection, quantification and degradation was performed. Firstly, an electrochemical cork-graphite sensor was prepared to identify/quantify HCQ in river water matrices by differential pulse voltammetric (DPV) method. Subsequently, an HCQ-polluted river water sample was electrochemically treated with BDD electrode by applying 15, 30 and 45 mA cm−2. The HCQ decay and organic matter removal was monitored by DPV with composite sensor and chemical oxygen demand (COD) measurements, respectively. Results clearly confirmed that, on the one hand, the cork-graphite sensor exhibited good current response to quantify of HCQ in the river water matrix, with limit of detection and quantification of 1.46 mg L−1 (≈3.36 µM) and 4.42 mg L−1 (≈10.19 µM), respectively. On the other hand, the electrochemical oxidation (EO) efficiently removed HCQ from real river water sample using BDD electrodes. Complete HCQ removal was achieved at all applied current densities; whereas in terms of COD, significant removals (68%, 71% and 84% at 15, 30 and 45 mA cm−2, respectively) were achieved. Based on the achieved results, the offline integration of electrochemical SDG6 technologies in order to monitor and remove HCQ is an efficient and effective strategy

Influence of mediated processes on the removal of Rhodamine with conductive-diamond electrochemical oxidation

The influence of the mediated oxidation on the removal of Rhodamine B (xanthene dye) solutions with conductive-diamond electrochemical oxidation (CDEO) is studied. To do this, four different supporting electrolytes have been used: Na2SO4, HClO4, H3PO4, NaCl. Total removal of organic pollutants is attained with CDEO regardless of the supporting electrolyte media used, although media clearly influences on efficiency and rate of the processes. Sulfate and phosphate media show a similar behavior, whereas electrolysis in perchlorate media behaves surprisingly better than chloride media. Current density is playing an important role. In all cases, CDEO follows a first order kinetic (linear trend in semi logarithmic plot) and kinetic constants are generally much greater than expected according to a single mass transfer electrolytic model. This is not the expected result for a direct electrochemical oxidation process and it indicates the importance of mediated electrochemical processes in the removal of Rhodamine B. The harsh oxidation conditions of CDEO leads to the formation of less reaction intermediates than other technologies. The presence of short chain aliphatic acids is discharted, and the intermediates (aromatic acids) formed during the initial stages of the process are rapidly mineralized to carbon dioxide. In chloride media, chlorinated intermediates are also formed by the action of hypochlorit

FATORES DE EXPOSIÇÃO PRÉ-NATAL E RISCO DE AUTISMO: UMA REVISÃO DE LITERATURA

<p><i><strong>Introdução</strong>:</i> A crescente prevalência do Transtorno do Espectro do Autismo (TEA) nas últimas décadas tem suscitado um interesse significativo na investigação dos fatores de risco associados a essa condição complexa. O diagnóstico do Transtorno do Espectro Autista (TEA) é baseado no quadro clínico apresentado pela criança, envolvendo o acompanhamento do desenvolvimento e a análise das atitudes exibidas, juntamente com entrevistas com os responsáveis. A etiologia exata do Transtorno do Espectro do Autismo (TEA) permanece desconhecida, no entanto, há um consenso crescente de que a interação entre fatores genéticos e ambientais desempenha um papel crucial em sua manifestação.A exposição pré-natal a substâncias tóxicas tem se tornado uma crescente preocupação de saúde pública, devido ao seu potencial impacto no desenvolvimento neurológico infantil <strong>Objetivo</strong>:avaliar fatores de exposição pré-natal possivelmente associados à incidência de TEA.<strong> </strong><i><strong>Metodologia</strong>: </i>Esta revisão sistemática de literatura foi estruturada, do ponto de vista metodológico, segundo os critérios propostos pela ferramenta PRISMA. Inicialmente, foram definidas as palavras-chave autismo e pré-natal. Posteriormente, a pesquisa foi realizada na base de dados MEDLINE, buscando estudos relacionados às palavras-chave que tivessem sido publicados nos últimos 10 anos. Nesse contexto,  foram encontrados 1103 estudos. No que se refere ao processo de triagem, em primeiro lugar excluiu-se artigos incompletos e estudos que não se relacionavam com as palavras-chave após análise de título e resumo. Posteriormente, os artigos restantes foram avaliados pelo seu texto completo por pelo menos dois autores. Em caso de discordância acerca da elegibilidade do artigo analisado, um terceiro autor participava do processo auxiliando na decisão final. <i><strong>Resultados: </strong></i>Os resultados mostraram que, após ajustes para fatores de confusão, crianças de mães com diagnóstico de depressão pré-natal apresentaram, em média, escores T do Sistema de Avaliação Social (SRS) 1,31 pontos mais altos em traços relacionados ao autismo em comparação com aquelas cujas mães não tiveram depressão pré-natal. Comparando crianças com exposição gestacional a benzodiazepínicos ou drogas Z e crianças sem essa exposição, observou-se uma taxa de risco ponderada de 1,40. <i><strong>Conclusão: </strong></i>A partir da análise dos artigos revisados, evidencia-se que a exposição a poluentes ambientais, especialmente o PM2,5; antibióticos e PFNA aumenta o risco de transtorno do espectro autista. Além disso, a presença de depressão durante o período gestacional também eleva a chance do recém-nascido apresentar traços autísticos. Enquanto isso, o consumo de benzodiazepínicos ou drogas Z durante a gestação não afetam conclusivamente o risco de autismo.</p&gt

Fenton: A Systematic Review of Its Application in Wastewater Treatment

The use of new technologies for the removal of pollutants from wastewater has become globally necessary due to the complexity and facilities defined by conventional treatments. Advanced oxidative processes, specifically the Fenton process, have become widely applied given their low cost and ease of use. Therefore, this study aimed to evaluate the progression of the scientific publications on the implementation of Fenton process, investigating their space–time evolution. Additionally, useful solutions, trends, and gaps in the applications for the removal of pollutants with this methodology were identified, and also different remediation strategies and the design of new treatments for wastewaters were identified within this scientometric analysis. Bibliometric research was conducted in two scientific databases, Web of Science and Scopus, from 2011 to 2022, and we identified 932 and 1263 studies with the word “Fenton,” respectively. When these publications are associated with the treatment of alternative effluents, an increase in publications from 2011 (r = 0.95, p r = 0.93, p < 0.001) was observed when analyzing both databases, indicating the relevance of the theme. Among these studies, several of them were conducted on the bench scale (89.8% and 98.3%, Web of Science and Scopus, respectively) and in aqueous matrix (97.8% and 98.4%, Web of Science and Scopus, respectively), with being China the main country with publications associated with these words (28.33% and 41.9%), while Brazil is related to 3.65% and 2.29% of the total studies in Web of Science and Scopus, respectively. In addition, this review provides a guideline for new applications for different species in the matrices and describes the evolution of technological solutions to meet Sustainable Development Goal 6: clean water and sanitation