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1.
Water Environ Res ; 96(8): e11090, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39112019

RESUMO

This study presents an innovative double-walled borosilicate glass reactor system for the efficient treatment of liquid and gaseous wastewater. This reactor system allows precise temperature control, continuous pH monitoring, and controlled dosing of reagents to optimize reaction conditions. Detailed characterization was carried out by X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), BET (specific surface area) analysis, point of zero charge (PZC), and scanning electron microscopy (SEM) for the SCR, SCRT, and 5%Fe@SCRT materials. For Malachite Green adsorption, SRCT demonstrated a maximum adsorption capacity of 39.78 ± 0.5 mg/g using the Langmuir isotherm model and followed pseudo-second-order kinetics. Optimum conditions for adsorption were found to be: an initial concentration of 50 ppm, an adsorbent dosage of 1 g/l, a pH of 8.5, and a temperature of 50°C. For the catalytic oxidation of phenol, 5%Fe@SRCT achieved a remarkable removal rate of 99.9 ± 0.1% under optimum conditions (50 ppm phenol, 1 g/l catalyst dosage, pH 3.5, H2O2 concentration 8.7 mM, and temperature 70°C). Intermediates identified during the reaction included hydroquinone, benzoquinone, catechol, and resorcinol, with degradation occurring over a 60-minute reaction period. The 5%Fe@SCRT material showed excellent reusability in the removal of phenol by catalytic oxidation, with no significant loss of efficiency over three cycles, while the SRCT underwent three cycles of regeneration for the adsorption of Malachite Green. Scavenger tests confirmed the involvement of hydroxyl radicals in the catalytic oxidation process. In addition, fish survival tests after catalytic oxidation of phenol by 5%Fe@SRCT showed no impact on fish, underlining the environmental safety of this process. In addition, germination tests after decolorization of MG by SRCT demonstrated a good effect with no negative impact, reinforcing the ecological value of this innovative technology. These results highlight the innovative use of SCRT and 5%Fe@SCRT as versatile materials for environmental remediation, exploiting their effective adsorption capacities and efficient catalytic oxidation performance within the proposed double-walled borosilicate glass reactor system. PRACTITIONER POINTS: The study demonstrates the effectiveness of an innovative reactor system employing SRCT adsorbent and Fe@SRCT catalyst for efficient removal of malachite green and phenol from wastewater. Environmental impact assessment, including seed germination and fish survival evaluation, validates the method's eco-friendly potential. Implementation of this approach could significantly contribute to sustainable water treatment practices.


Assuntos
Corantes de Rosanilina , Poluentes Químicos da Água , Corantes de Rosanilina/química , Adsorção , Poluentes Químicos da Água/química , Animais , Catálise , Argila/química , Peixes , Fenol/química , Sementes , Eliminação de Resíduos Líquidos/métodos , Ferro/química , Purificação da Água/métodos , Silicatos/química
2.
Int J Biol Macromol ; 120(Pt A): 1181-1189, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30172808

RESUMO

Chitin is the second most common polymer after cellulose in earth, existing in the shells of crustaceans like crab and shrimp. Chitosan is a natural amino-polysaccharide derived from chitin, known as one of the most abundant organic materials in nature, it has been widely used in several applications due to its natural origin and exceptional properties such as biocompatibility, biodegradability, non-toxicity, and chelating of metal ions. Chitin and chitosan are characterized by deacetylation degree, one of the most important chemical characteristics that can influence the performance of chitosan in many applications. Chitosan is usually prepared by a thermochemical method, consuming time, energy and reagents. In this review, various methods of chitosan extraction will be approached and compared; the importance of a new method of ecological extraction will be emphasized. Moreover, in order to improve the chitosan functionality, and better control these physicochemical properties, several chemical modifications have been reported. These chemical modifications lead to a broad range of derivatives with a wide range of applications in many fields. Recent examples of the distinct applications, with particular emphasis on environmental applications, have been presented.


Assuntos
Quitina/química , Quitosana/química , Polissacarídeos/química , Animais , Braquiúros/química , Quitosana/síntese química , Crustáceos/química
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