Papers by Keyword: Nitrobenzene

Abstract: Direct laser processing of various materials with nano- and femtosecond (fs) laser pulses is known to be a facile and inexpensive technology for fabrication of various surface morphologies. Since ultrafast deposition of the laser energy to target material typically creates unique experimental conditions with extremely high pressure and temperature, we hypothesized that carrying out this process in anhydrous non-oxidizing environment containing functionalizing agent (fluorophore with vinyl functional group) will allow one-step fabrication and subsequent functionalization of the surface of high-n material. In this paper, we demonstrate successful implementation of this idea by fabricating high-spatial-frequency laser-induced periodic surface structures (LIPSS) via direct fs-pulse ablation of bulk crystalline Si wafer immersed in solution of N-vinylcarbazole in toluene. Laser processing with linearly polarized fs-laser pulses was found to produce LIPSS with a characteristic period around 100 nm functionalized with N-vinylcarbazole molecules via photo-activated hydrosililation reaction. The unique LIPSS with hierarchical roughness and remarkable light trapping performance functionalized with sensory fluorophore show high sensitivity due to implementation of surface enhanced fluorescence effect. By using N-vinylcarbazole as functionalizing agent we demonstrate one-step fabrication of high-performance sensor for detecting nitrobenzene in water with a detection limit of 40 nM.

Abstract: Through indoor simulation experiment, this paper determines the main factors influenced the migration and transformation in aquifer, and calculate the influence degree of these factors by analytic method. Research shows that the adsorption capacity of nitrobenzene in silt medium greater than in sand medium, the block coefficient of silt medium was 2.22, block coefficient and sand medium was 1.74. Based on the first-order kinetic equation, respective of silt medium natural decay rate constant is 0.0644/h, sand medium natural decay rate constant is 0.0056/h.

Abstract: This paper researched the linear relationship between UV absorbance and concentrations of nitrobenzene. It used the UV-1700 UV/VIS spectroscopy to get the absorbance diagram and analyze it. Then it calculated the absorbance of maximum absorption peak and the absorbance integration in a wavelength interval. There is a linear relationship between absorbance and concentration, the correlation coefficient is 0.981 of the maximum absorption peaks and the concentrations, and the largest correlation coefficient between concentrations and the integration of absorbance is 0.995 with the wavelength interval of 235-245 nm, which is between the two absorption peaks of 210 nm and 270 nm. Therefore, it’s a good way to use integration of absorbance in the middle of two absorption peaks to measure the concentration of nitrobenzene, which is more accurate and reliable.

Abstract: In this paper, activated sludge process enhanced by ultrasound was applied to treat the chemical production wastewater containing nitroaromatic compound after ultrasonic pretreatment. The factors influence to treatment effect such as ultrasound power and frequency, irradiation time were investigated by experiment. The mechanism of ultrasound enhanced activated sludge process was analyzed. The experimental results show that ultrasonic irradiation with appropriate parameters can effectively enhance sludge activity, improve the treatment efficiency. The optimal treatment conditions are as follows: ultrasound power 10W, frequency 25kHz, irradiation time 15min.

Abstract: In this study, we choose TiO₂ as photocatalysis, and to deal with low concentration nitrobenzene containing wastewater under the shining of ultraviolet light. The dosage of TiO₂, H₂O₂ and FeCl₃ and DO have be inspected. The following conclusion is according to the experiment result: When nitrobenzene 's concentration deciding for 20mg/L and the concentration of TiO₂, H₂O₂ and FeCl₃ are respectively 3.0g/L , 2.0mL/L, it is better to get the optimum removal rate.

Abstract: Mg_xMn_1-xFe₂O₄ (x = 0.0, 0.2, 0.4, 0.5, 0.6 0.8 and 1.0) spinel ferrite system was synthesized by the chemical co-precipitation route. Subsequent characterization of synthesized Mg-Mn ferrites was carried out by X-ray powder diffraction and transmission electron microscopy to study the structural and textural properties of photocatalysts. Porosity, surface area and equivalent surface free energy of different Mg-Mn ferrite photocatalysts were calculated. The photocatalytic activity of synthesized photocatalysts was evaluated by degradation of nitrobenzene in aqueous medium under ultraviolet light irradiation. The results demonstrated that the percentage degradation of nitrobenzene was decreased with increase in Mg concentration (x) from x = 0.0 0.5 and further increase in concentration from x = 0.6 1.0 results increase in percentage degradation of NB. This dissimilarity in the percentage degradation of NB may be due to the change in grain morphology, optical energy band gap, role played by d-electrons and porosity as a function of Mg-substitution for Mn²⁺ in the system. The percentage degradation was further confirmed by chemical oxygen demand (COD) analysis.

Abstract: NB reduction with NZVI will be effected by factors. In this study, batch experiments were carried out to evaluate the single and combined actions of common dissolved ions including HCO3-, Cl-, SO42-, NO3-, Mg2+ and Ca2+. The results showed that the removal efficiency of NB was enhanced with the increase of the concentration of added HCO3-, Cl-, SO42-, NO3- as a descending order, and SO42- would be an inhibitor when its concentration was lower than 250 mg/L. Mg2+ and Ca2+ themselves had no obvious influences on NB reduction with SM-NZVI, but they could weaken the positive effects of other coexisting ions like Cl- and SO42-. Coexistence of these dissolved ions would promote metal carbonate precipitations and thus made against NB degraded and aniline produced.

Abstract: In the paper, the PbO2-Ti electrodes were characterized by SEM, and introduce the self-made catalyst Fe3+/TiO2 into the electrolytic system to treat the nitrobenzene wastewater, in order to improve the reaction speed and the removal rate of COD and NB and form heterogeneous electro-catalytic oxidation technology. In order to confirm the best removal efficiency of COD and NB, the experiment will study the electrolysis time, current intensity, pH value, and the amount of catalyst. The experimental results showed that the surface of La-doped electrode was dense and had good electro-catalytic properties.

Abstract: Treatment of nitrobenzene-containing wastewater was carried out by iron-carbon internal electrolysis and microwave and its degradation mechanism was investigated. The parameters is found in the process of treating nitrobenzene-containing wastewater. The experimental results showed that the microwave intensified the internal electrolysis effect of iron-carbon and the existence of iron was beneficial to the regeneration of activated carbon. Under the optimized electrolysis conditions as follows: iron dosage was 175g, molar ratio of Fe to C was 3, pH was 3, microwave power was 640W, irradiation time was 4 min and aeration amount was 2.5L/min, the removal rates of CODcr, chroma and turbidity were 94.7 %, 95.6 % and 90.3 %, respectively.

Abstract: The electrochemical reduction behaviors of nitrobenzene in composite ionic liquids were investigated by cyclic voltammetry. The results showed that the electrochemical reduction characteristics of nitrobenzene in binary composite ionic liquids was improved in comparing with pure ionic liquids BMimBF4 and BMimPF6. The reaction velocity of nitrobenzene in composite ionic liquids was controlled by diffusion. With increasing temperature or the concentration of nitrobenzene, the peak current was increased and the peak potential was varied complicated.