Evaluation of a graphitic porous carbon modified with iron oxides for atrazine environmental remediation in water by adsorption.

In the last decades, the growth of world agricultural activity has significantly contributed to the increased presence of emerging pollutants such as atrazine (ATZ) in aquatic ecosystems. Due to its high stability to the natural or artificial degradation processes, the ATZ environmental remediation by adsorption has been investigated. In this study, a graphitic-porous-carbon- (GPC) based material with magnetic domains was applied to remove ATZ from aqueous solution.

UV-Vis spectrophotometry coupled to chemometric analysis for the performance evaluation of atrazine photolysis and photocatalysis.

In this study, a spectrophotometric-chemometric (Spec-Chem) approach was applied as an alternative to chromatography to monitor ATZ and by-products after photolytic and photocatalytic oxidation aiming to unveil the ATZ degradation mechanism. Spec-Chem is an accessible, easy-to-operate, low-cost analytical approach to monitor atrazine (ATZ) and by-products, and its applicability was validated by HPLC, the reference technique for the evaluation of pollutant degradation mechanisms. The chromatographic (DChro) and spectrophotometric (DSpec) data found 95% and 57% ATZ removal after 30 min, respectively, proving that the DSpec erroneously induces a 38% loss in removal efficiency.

Potential of NbO nanofibers in photocatalytic degradation of organic pollutants.

Various photocatalytic nanomaterials for environmental remediation have been promoted due to the pollution caused by different organic pollutants. In this study, NbO nanofibers were obtained by electrospinning technique, presenting controlled crystallinity and high specific surface area to improve the photoactivity response. The structural characterization indicated NbO nanofibers with orthorhombic phase formation.

N-compounds speciation analysis in environmental samples using ultrasound-assisted solid-liquid extraction and non-chromatographic techniques.

A fast, efficient, and non-chromatographic method was presented in this study for nitrite, nitrate, and p-nitrophenol (N-compounds) extraction and speciation analysis of environmental samples. By applying ultrasound-assisted solid-liquid extraction (USLE), analytes were efficiently extracted from water, soil, or sediment collected in areas of environmental disaster. These analytes were selectively converted to NO through UV photolysis (NO), HO/UV photocatalysis (PNP), and direct conversion (NO).

NbO nanoparticles decorated with magnetic ferrites for wastewater photocatalytic remediation.

Nanotechnology has been studied on environmental remediation processes to foster greater photocatalysts efficiency and reuse in wastewater. This study investigated the photocatalytic efficiency and viability of niobium pentoxide (NbO) nanoparticles decorated with magnetic ferrite (cobalt ferrite (CoFeO) or magnesium ferrite (MgFeO)) for atrazine photodegradation. Thus, the decorated NbO was synthesized by the polymeric precursor method, forming nanoparticles with sizes ranging from 25 to 50 nm.

Photocatalytic degradation of Prozac® mediated by TiO nanoparticles obtained via three synthesis methods: sonochemical, microwave hydrothermal, and polymeric precursor.

Three different synthesis methods were applied to obtain TiO nanoparticles: microwave-assisted hydrothermal (TiO-MW), sonochemical (TiO-US), and polymeric precursor (TiO-PP). The nanoparticles thus obtained presented 93% (TiO-MW) and 92% (TiO-US) anatase phase, and TiO-PP 93% rutile phase. The TiO-US sample performed best during the Prozac® photodegradation assays because of its lipophilic surface, attributable to the C-H groups therein.

Growth of the aquatic macrophyte Ricciocarpos natans (L.) Corda in different temperatures and in distinct concentrations of aluminum and manganese.

One of the consequences of global mining is the exposure of metals into the environment, caused by the rupture of tailings dams. Excess of metals, such as aluminum (Al) and manganese (Mn) can cause serious damage to fauna and flora. The presence of these metals, associated with the temperature increase that occurs nowadays can potentially increase biochemical and metabolic rates in plant tissues and may affect growth.

UV photochemical hydride generation using ZnO nanoparticles for arsenic speciation in waters, sediments, and soils samples.

The environmental disasters that occurred due to the leakage of mining waste in Mariana-MG (2015) and Brumadinho-MG (2019), located in Brazil, attracted the attention of the scientific community. This designated efforts to investigate the environmental consequences of toxic waste in the affected ecosystem. Therefore, a simple, easily executed and accessible method was presented for arsenic speciation [As(III), As(V), and DMA].

Speciation of As in environmental samples using the nano-TiO/PCHG-FAAS online system.

This work presents an alternative method for arsenic speciation using the nano-TiO hydride generation photocatalytic hydride generation (PCHG) system, which is easily separated from the medium. Nano-TiO was studied as photocatalyst to reduction of arsenic species by UV-induced with formic acid and atomic absorption detection of different forms of arsenic [As (III), As (V), dimethylarsinic acid (DMA)] in environmental samples (water, sediment and plant). The effect of the average pH, the organic acid concentration, the ultraviolet irradiation time and their amount were investigated.

Evaluation of atrazine degradation applied to different energy systems.

Atrazine is an herbicide widely used in crops and has drawn attention due to potential pollution present in soil, sediment, water, and food. Since conventional methods are not potentially efficient to persistent degradation of organic compounds, new technology has been developed to remove them, especially practices utilizing advanced oxidation processes (AOPs). This work aims to evaluate the use of different energies (ultraviolet (UV), microwaves (MW), and radiations (MW-UV)) to the herbicide atrazine through the process of photo-oxidation.

Evaluation of atrazine degradation applied to different energy systems.

Atrazine is an herbicide widely used in crops and has drawn attention due to potential pollution present in soil, sediment, water, and food. Since conventional methods are not potentially efficient to persistent degradation of organic compounds, new technology has been developed to remove them, especially practices utilizing advanced oxidation processes (AOPs). This work aims to evaluate the use of different energies (ultraviolet (UV), microwaves (MW), and radiations (MW-UV)) to the herbicide atrazine through the process of photo-oxidation.