The Oxidation Mechanism of Aniline by Ozone Water and Ozone Micro-nano Bubble Water and Its Influencing Factors

Aniline is a kind of refractory contaminant that is difficult to be degraded by microorganisms. Ozone is a green and efficient reagent to oxidize aniline, while the ozone oxidation efficiency is restricted by the low ozone mass transfer rate. Micro-nano bubble ozonation has been developed as a new method to significantly improve the ozone utilization rate, while the characteristics of ozone micro-nano bubble when compared with dissolved ozone is not clear. The paper carried out batch experiments to research the oxidation effect of aniline by ozone water (OW) and ozone micro-nano bubble water (OMNBW), and found that the degradation rate of aniline by OMNBW was 2.8~5.9% higher than that by OW. The increase of pH had a negative effect on the degradation of aniline by OW and OMNBW. SO42-, Cl-, HCO­3- and Mg2+ could inhibit the degradation efficiency by 0.04%, 0.99%, 0.44% and 10.4% for OW, while the ratios were 1.1%, 6.4%, 4.1% and 1.5% for OMNBW. The addition of humic acid and fulvic acid could decrease the oxidation rate of aniline by 35% and 49% for OW, while the ratios were 41% and 62% for OMNBW. Through quenching experiment, it was found that the direct oxidation by ozone molecules and the indirect oxidation by superoxide radicals were main pathways for aniline oxidation by OW and OMNBW. This work provided a practical guide for the application of OMNBW in wastewater and groundwater treatment process.

Synthesis of rhombohedral LaCuO3 thin films using oxidation effect of NaClO solution

LaCuO3 is one of the most fundamental cuprate perovskite block which has a similar structure to the cuprate high-temperature superconductor. Therefore, some consider that the study on LaCuO3 is one...

Aktivitas Antioksidan Ekstrak Etanol Temu Blenyeh (Curcuma Purpurascens Blumae) Dengan Metode Dpph (1,1 Diphenyl-2-Picrylhydrazyl)

ABSTRACTAntioxidants have a function to scavenge and neutralize oxidation effect caused by free radicals by preventing the formation of radicals. Temu blenyeh (Curcuma purpurascens Bl) is one of the curcuma species which is still under-researched. Traditionally, temu blenyeh is used to treat stomachache, cough, itch, and skin infection. Some studies show that temu blenyeh extract had antioxidants activity and anti-cancer. The extract contains flavonoid, terpenoid, steroid, triterpenoid, essential oil. The study aimed to determine antioxidant activity of ethanol extract of temu blenyeh using DPPH method. Temu blenyeh was extracted by maceration with 96% ethanol solvent. The antioxidants activity test described that the value of IC50 was 48.697 ppm. Keywords: Temu blenyeh, DPPH, antioxidants Abstrak Antioksidan berfungsi untuk menangkal dan menetralisasi efek oksidasi yang disebabkan radikal bebas dengan cara mencegah terbentuknya radikal. Temu blenyeh (Curcuma purpurascens Bl) salah satu spesies curcuma yang masih sedikit diteliti. Temu blenyeh secara tradisional digunakan untuk mengobati sakit perut, batuk, gatal, dan infeksi kulit. Beberapa penelitian membuktikan bahwa ekstrak rimpang temu blenyeh memiliki aktivitas antioksidan dan anti kanker. Temu blenyeh mengandung flavonoid, terpenoid, steroid, triterpenoid dan minyak esensial. Penelitian ini bertujuan untuk mengetahui adanya aktivitas antioksidan pada ekstrak etanol temu blenyeh menggunakan metode DPPH. Temu blenyeh diekstraksi dengan metode maserasi menggunakan pelarut etanol 96%. Dalam penelitian uji aktivitas antioksidan ekstrak etanol temu blenyeh menunjukkan hasil nilai IC50 sebesar 48,697 ppm. Kata kunci : Temu blenyeh; DPPH; Antioksidan

Improvement on Conductivity for Thick Film Aluminum Paste

With the development of thick-film paste, silver and copper are circulating in the market as the electric conductive fillings currently. Unfortunately, the cost of silver is exceedingly high, while the copper has to be sintered in the reducing atmosphere. In this study, we proposed to exert aluminum as the filling due to its low cost, good electrical conductivity, and capability of being sintered in air. By means of the fracture mechanism of the oxidation layer of the Al surface and the liquid phase sintering, the Al paste with high solid content is used to implement high electrical conductivity. Based on that Al powder with large particle size tends to fracture easily, while it is easy for Al powder with small size to fill the gap, we mixed Al powder with large and small particle sizes at different proportion, so that the internal micro-structure and the oxidization are observed. However, when glass frit was added into mixed Al powder, the Al particles are wet by glass frit for bonding Al particles as well as inhibiting oxidation. Effect of the glass frit content and the solid content of Al paste on conductivity are investigated in this study. The sheet resistance of Al paste sintered at 850 °C for 10 min. can be reduced to 4.5 mΩ/□ when Al paste is formulated based on the mixed Al particles with proportion of big to small (4:1) at 10 wt% glass frit content and 80 wt% solid content.

Improvement on Conductivity for Thick Film Aluminum Paste

With the development of thick-film paste, silver and copper are circulating in the market as the electric conductive fillings currently. Unfortunately, the cost of silver is exceedingly high, while the copper has to be sintered in the reducing atmosphere. In this study, we proposed to exert aluminum as the filling due to its low cost, good electrical conductivity, and capability of being sintered in air. By means of the fracture mechanism of the oxidation layer of the Al surface and the liquid phase sintering, the Al paste with high solid content is used to implement high electrical conductivity. Based on that Al powder with large particle size tends to fracture easily, while it is easy for Al powder with small size to fill the gap, we mixed Al powder with large and small particle sizes at different proportion, so that the internal micro-structure and the oxidization are observed. However, when glass frit was added into mixed Al powder, the Al particles are wet by glass frit for bonding Al particles as well as inhibiting oxidation. Effect of the glass frit content and the solid content of Al paste on conductivity are investigated in this study. The sheet resistance of Al paste sintered at 850 °C for 10 min. can be reduced to 4.5 mΩ/□ when Al paste is formulated based on the mixed Al particles with proportion of big to small (4:1) at 10 wt% glass frit content and 80 wt% solid content.