RESUMO
The removal of Rhodamine B (RhB) by Co(x)Fe(3-x)O(4) magnetic nanoparticles activated Oxone has been performed in this study. A series of Co(x)Fe(3-x)O(4) nanoparticles was synthesized using a hydrothermal method. The synthetic Co(x)Fe(3-x)O(4) nanoparticles were characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results showed that they were spinel structures and Co was introduced into their structures. The performances of Co(x)Fe(3-x)O(4) nanocatalysts on the activation of Oxone for removal of RhB were investigated and we found that the higher cobalt content in the catalyst, the better removal performance was resulted. A series experiments of reaction conditions were also performed, which confirmed that weak acidic, higher temperature, higher dosages of Co(x)Fe(3-x)O(4) nanocatalyst and Oxone and lower concentration of RhB were favored for the degradation of RhB. The pseudo-first order kinetics was observed to fit the Co(x)Fe(3-x)O(4)/Oxone process. Furthermore, the reaction mechanism was discussed and the scavenging effect was examined by using phenol and tert-butyl alcohol which indicated that sulfate radicals were the dominating reactive species responsible for the degradation process. Finally, the stability of Co(x)Fe(3-x)O(4) nanocatalyst was studied.
Assuntos
Cobalto/química , Compostos de Ferro/química , Nanopartículas Metálicas/química , Rodaminas/química , Ácidos Sulfúricos/química , Poluentes Químicos da Água/química , Análise da Demanda Biológica de Oxigênio , Catálise , Corantes/química , Concentração de Íons de Hidrogênio , Temperatura , Eliminação de Resíduos Líquidos/métodosRESUMO
A sensitive and efficient analytical method for triclosan (TCS) determination in water, which involves enrichment with bamboo-activated charcoal and detection with HPLC-ESI-MS, was developed. The influence of several operational parameters, including the eluant and its volume, the flow rate, the volume andacidity of the sample, and the amount of bamboo-activated charcoal, were investigated and optimized. Under the optimum conditions, linearity of the method was observed in the range of 0.02-20 µg/L, with correlation coefficients (r(2) ) >0.9990. The limit of detection was 0.002 µg/L based on the ratio of chromatographic signal to baseline noise (S/N = 3). The spiked recoveries of TCS in real water samples were achieved in the range of 97.6-112.5%. The proposed method was applied to analyze TCS in real aqueous samples. All the surface water samples collected in Xiaoqing River had detectable levels of TCS with concentrations of 42-197 ng/L.
Assuntos
Carvão Vegetal/química , Cromatografia Líquida de Alta Pressão/métodos , Extração em Fase Sólida/métodos , Espectrometria de Massas por Ionização por Electrospray/métodos , Triclosan/análise , Triclosan/isolamento & purificação , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/isolamento & purificaçãoRESUMO
Degradation of the antibiotics amoxicillin in aqueous solution using sulphate radicals under ultrasound irradiation was investigated. The preliminary studies of optimal degradation methodology were conducted with only oxone (2KHSO(5) · KHSO(4) · K(2)SO(4)), cobalt activated oxone (oxone/Co(2+)), oxone+ultrasonication (oxone/US) and cobalt activated oxone+ultrasonication (oxone/Co(2+)/US). The chemical oxygen demand (COD) removal efficiency were in the order of oxoneAssuntos
Amoxicilina/química
, Sonicação/métodos
, Sulfatos/química
, Sulfatos/efeitos da radiação
, Poluentes Químicos da Água/química
, Purificação da Água/métodos
, Água/química
, Amoxicilina/isolamento & purificação
, Amoxicilina/efeitos da radiação
, Radicais Livres/química
, Radicais Livres/efeitos da radiação
, Ondas de Choque de Alta Energia
, Doses de Radiação
, Soluções
, Poluentes Químicos da Água/isolamento & purificação
, Poluentes Químicos da Água/efeitos da radiação