Degradation of chloramphenicol and metronidazole by electro-Fenton process using graphene oxide-Fe3O4 as heterogeneous catalyst
Gözmen Belgin | Görmez Özkan
This study investigates the degradation and mineralization of two widely used antibiotics, chloramphenicol and metronidazole, by an electro-Fenton process using graphene oxide-Fe3O4 as a heterogeneous catalyst. The graphene oxide-Fe3O4 composite was typically characterized through conventional spectroscopic and surface analytical methods. The effects of treatment time, pH, catalyst concentration and applied current were examined. In the absence of the graphene oxide-Fe3O4 catalyst (homogeneous environment), the optimum mineralization rates obtained were 57 and 71% at pH 3 and 300 min treatment time for metronidazole and chloramphenicol solutions, respectively. When the optimum graphene oxide-Fe3O4 concentration of 0.5 g L−1 was used, mineralization rates of 73 and 86% were achieved respect...
Enhancement of photocatalytic activity of carbon nitride/black phosphorus/tungsten disulfide (CN/BP/WS2) heterojunctions via nickel doping in the hydrogen evolution reaction
Altan, Orhan
The complementary properties of mesoporous graphitic carbon nitride (m-CN) and black phosphorus (BP) as non-metallic semiconductors offer many opportunities for the rational design of efficient photocatalysts for the photocatalytic hydrogen evolution reaction (HER). However, pristine m-CN and BP exhibit significant photoinduced charge carrier recombination rates and weak light absorption, resulting in a low photocatalytic HER activity. To overcome these problems and improve their photocatalytic HER activities, rational design of heterojunctions is one of the most efficient ways. Here, we present for the first time the ternary m-CN/BP/WS2 dual S-scheme heterojunctions, prepared by combining as-prepared m-CN/BP hybrids with tungsten disulfide (WS2). Encouragingly, the ternary m-CN/BP/WS2 het...
Adsorption of 2,4-dichlorophenol on paper sludge/wheat husk biochar: Process optimization and comparison with biochars prepared from wood chips, sewage sludge and hog fuel/demolition waste
Gözmen Belgin
The adsorption of 2,4-dichlorophenol, a toxic by-product of triclosan commonly found in wastewater treatment plant effluents, was studied on paper sludge/wheat husks biochar. By using response surface methodology, the optimum conditions and effects of pH, temperature, initial 2,4-DCP concentration and time were determined. The solution pH was found to be the most influential parameter whereas the optimum adsorption conditions were predicted as: C0 = 40.28 mg L−1 , T = 326 K, pH = 2.8, t = 143 min, where a 99.95% adsorption could be achieved. Both Langmuir and Freundlich provided a good fit for the experimental data, indicating a surface and multi-layer adsorption. Kinetically, the process primarily followed the pseudo-second order model (chemisorption). By comparing the adsorption c...