Call me! Click here to send us a message

Company news

Removal of phenol by activated alumina bed

Useradmin AddDate2015/6/14 Read4911Times

Removal of phenol by activated alumina bed in pulsed high-voltage electric field

Abstract

A new process for removing the pollutants in aqueous solution-activated alumina bed in pulsed high-voltage electric field was investigated for the removal of phenol under different conditions. The experimental results indicated the increase in removal rate with increasing applied voltage, increasing pH value of the solution, aeration, and adding Fe2+. The removal rate of phenol could reach 72. I% when air aeration flow rate was 1200 mVrnin, and 88.2% when 0.05 mmol/L Fe2 + was added into the solution under the conditions of applied voltage 25 kV, initial phenol concentration of 5 mg/L, and initial pH value 5.5. The addition of sodium carbonate reduced the phenol removal rate. In the pulsed high-voltage electric field, local discharge occurred at the surface of activated alumina, which promoted phenol degradation in the thin water film. At the same time, the space-time distribution of gas-liquid phases was more uniform and the contact areas of the activated species generated from the discharge and the pollutant molecules were much wider due to the effect of the activated alumina bed. The synthetical effects of the pulsed high-voltage electric field and the activated alumina panicles accelerated phenol degradation.

Conclusions

A new process for removing the pollutants in aqueous solution-activated alumina bed in pulsed high-voltage electric field was investigated for the removal of phenol. The phenol removal rate increased with increasing applied voltage, increasing pH value of the solution, air aeration, and adding Fe2+. The addition of sodium carbonate reduced the phenol removal rate because it was a radical scavenger. The additive of Fe2+ could promote the phenol degradation mainly due to the formation of OH.  With the discharge progressing, phenol could be mineralized to form C02 and H10. In the pulsed high-voltage electric field, the activated alumina particles could be polarized when the pulsed high voltage was applied on the electrodes, which induced the formation of the local discharge and increased the phenol removal in the thin water film. At the same time, the space-time distribution of gas-liquid phases was more uniform and stable and the contact areas of activated species generated from the discharge and the pollutant molecules were much wider due to the effect of the activated alumina bed. The contrary flow of liquid and gas brought the disturbed flow at the boundary surface of gas-liquid phases, which was beneficial to the mass transfer and diffusion of activated particles generated in the discharge region to the water film.

Although this method needs some energy consumption, its advantage is obvious. It can produce many active species, such as OH, 03, H202, and so on synchronously, which has high oxidation potential and can oxidize organic pollutions effectively. And it can be used for the water deep oxidation for drinking at lower concentration. The microorganisms' degradation method is limited for the lower nutriment concentration. But the reaction system should be studied continuously and optimized for obtaining higher energy efficiency.


This paper is not provided free of charge by the author, but Yuanying Industry Limited has to pay related fees, because of the intellectual property rights cannot be published in full, if you need to read the full article, please contact us, we sent to you by email