Nonylphenol ethoxylate degradation in detergents during shelf time, a new exposure pathway, and a perspective on their substitution.

Detergents are highly produced pollutants with environmental problems like foam generation and toxic effects in biota. Nonylphenol ethoxylates (NPEs) are efficient, economical, and versatile surfactants, used in detergents for more than 40 years due to their detergency capacity. In the environment, NPE biodegrades into the metabolite nonylphenol (NP), classified as an endocrine disruptor. The identification and quantification of 4-NP in a designed detergent and 30 commercially available detergents were performed to prove the degradation of NPE into 4-NP during storage time. This investigation introduces the first evidence of NPE degradation during storage in commercially available detergents, demonstrating a novel exposure pathway in humans that has not been explored before, representing potential human health risks. Therefore, simple, easy, low-cost, and available approaches to remove and substitute NP is paramount. Alkyl polyglucoside (APG) was assessed as a substitute, and the feasibility of this substitution was proven according to physical and chemical properties, cleaning performance, and antimicrobial properties. NPE substitution in detergents is demonstrated as a viable strategy to minimize exposure risks in humans and the environment.

Adsorción de Cd(II) y Pb(II) presentes en solución acuosa con hueso de nanche (Byrsonima crassifolia) / Adsorption of Cd(ll) and Pb(ll) present in aqueous solution with nanche stone (Byrsonima crassifolia) / Adsorção de Cd(ll) e Pb(ll) presente em solução aquosa com osso nanche (Byrsonima crassifolia)

Resumen El hueso de nanche es un residuo agrícola con gran potencial de uso como adsorbente. Al respecto, se evaluó la capacidad de adsorción de iones Cd(II) y Pb(II), presentes en solución acuosa, utilizando este residuo. Las pruebas realizadas en este estudio fueron: la determinación del punto de carga cero (pHPZC), determinación de sitios activos (método de Boehm y espectroscopía FTIR) y el desarrollo de los modelos matemáticos de Langmuir, Freundlich y Prausnitz-Radke, a través de isotermas de adsorción. Los resultados obtenidos del pHPZC del hueso de nanche estuvieron en un rango ácido (6,0), mientras que la concentración de sitios ácidos y básicos fue de 0,1037 y 0,046 mol/g, respectivamente. Los espectros infrarrojos (FTIR) detectaron sitios funcionales ácidos asociados al grupo fenol, ácidos carboxílicos y lactonas. Finalmente, la capacidad de adsorción del hueso de nanche para Cd(II) y Pb(II) se incrementó con el pH y alcanzó porcentajes de remoción hasta de 84 % para Cd(II) a pH 8, y de 82% para Pb(II) a pH 5. En conclusión, el pH y la presencia de sitios funcionales ácidos fueron determinantes en la eliminación de los iones Pb(II) y Cd(II).

Abstract The nanche stone is an agricultural residue that has great potential as adsorbent. Then, the adsorption capacity of Cd(II) and Pb(II) ions present in aqueous solution was evaluated, using the stone as adsorbent. The tests performed for this purpose were the determination of point of zero charge (pHPZC), determination of active sites (Boehm method and FTIR spectroscopy), and the development of the mathematical models of Langmuir, Freundlich, and Prausnitz-Radke through adsorption isotherms. The results obtained from the pHPZC of the nanche stone were in an acidic range (6,0), while the concentration of acid and basic sites were 0.1037 and 0.046 mol/g respectively. The infrared spectra (FTIR) detected acid functional sites associated with the phenol group, carboxylic acids, and lactones. Finally, the adsorption capacity of nanche stone to Cd(II) and Pb(II), increased with the pH, achieving percentages of removal up to 84% for Cd (II) to pH 8, and of 82% for Pb(II) to pH 5. In conclusion, the pH and the presence of acidic functional sites were decisive in the elimination of the Pb(II) and Cd(II) ions.

Resumo O osso Nanche é um resíduo agrícola que possui grande potencial como adsorvente, neste respeito, a capacidade de adsorção de íons Cd(II) e Pb(II) presentes em solução aquosa foi avaliada, utilizando osso como adsorvente. Os testes realizados para este fim foram a determinação do ponto zero de carga (pHPZC), a determinação de sites ativos (método Boehm e espectroscopia FTIR) e o desenvolvimento dos modelos matemáticos de Langmuir, Freundlich e Prausnitz-Radke através de isotermas de adsorção. Os resultados obtidos do pHPZC do osso nanche foram em uma faixa ácida (6,0), enquanto a concentração de ácidos e sites básicos foram 0,1037 e 0,046 mol / g, respectivamente. Os espectros de infravermelho (FTIR) detectaram sites funcionais ácidos associados ao grupo fenol, ácidos carboxílicos e lactonas. Finalmente, a capacidade de adsorção do osso nanche para Cd(II) e Pb(II), aumentou com o pH, atingindo porcentagens de remoção de até 84% para o Cd(II) em pH 8, e 82% para Pb(II) a pH 5. Em conclusão, o pH e a presença de sites funcionais ácidos foram decisivos na eliminação dos íons Pb (II) e Cd (II).