| Activated carbon has a strong adsorption performance, so it is very simple and quick to remove the refractory substance in the water with the activated carbon adsorption.Regeneration of the saturated activated carbon can save resources, and avoid the second pollution of pollutants effectively. And the dielectric barrier discharge(DBD), as a new kind of technology, may produce a certain intensity of UV light and a large number of high energy activation particles,using the techniqueand.So it has a very good prospects in the activated carbon modified and regeneration.In this paper, some researches has been done on the effects of oxygen on DBD modified granular activated carbon(GAC) and on the regeneration of adsorption of phenol saturated activated carbon,using the DBD device.The experiment is to investigate the effect of oxygen on the experiment results under various conditions.And the various conditions are as follows:the power supply plate spacing-discharge voltage, discharge time, power frequency, type and rate of the gas.The impact of oxygen on the DBD modified GAC experiment was analyzed by means of ASAP physical adsorption instrument, and the main mechanism of the effect of oxygen on GAC modification was obtained. And the effect of oxygen on the carbon loss rate of saturated GAC was studied.The main results are as follows:(1)All the experiments show that while the reactor is filled with oxygen, the discharge reactor is more uniform and stable, and micro discharge color from purple-red to blue-white.Regardless of the rate of the oxygen flow, the oxygen has certain extent to enhance the effect on GAC modification and regeneration of Saturated GAC.For this experiment, the best combination of GAC modification is:plate spacing- discharge voltage, 10mm-10 kV, the amount of GAC3.0g, oxygen flow3L/min, power frequency 10 kHz, discharge time 15 min.At the optimum conditions,the adsorption capacity of GAC was increased by 17.76% compared with that of none modified.And the adsorption capacity of GAC was increased by 6.56% compared with that in the air.(2) According to the results of all experiments, the discharge time is the most important factor that influences the effects on DBD modification and regeneration of activated carbon. From the experimental results we can know that the best modification time of GAC is 15 min in advance by the original 20 min after the oxygen in the air. However, oxygen is the least influencing factors amount the 4factors which influence the GAC modification. Under the optimum conditions of GAC regeneration, the regeneration rate of GAC was 82.36%, and the regeneration rate of GAC was increased by 5.58% compared with that without oxygen.(3) According to the experimental results, in the DBD modified GAC experiments, oxygen can further reduce the number of total alkaline group and further increase the amount of total acidic group in the GAC surface; at the same time, the amount of lactone will further reduce, and the number of hydroxyl and phenolic hydroxyl will increases more. The experimental results show that oxygen can promote DBD reaming on GAC, and further enhance the modification effect of GAC.(4) Oxygen makes the reaction region forming more O3 and other active particles and promote the GAC surface oxygen functional groups increased, making the amount of hydrogen bonds on the GAC surface increased, thereby increasing the GAC and the phenol in water hydrogen bond force, finally,the GAC adsorption performance can be improved.(5) Through 5 experiments, we found that the oxygen may decrease the carbon loss rate of saturated GAC in different degree. The treatment of phenol in aqueous solution in oxygen atmosphere, can produce catechol, benzoquinone,hydroquinone,and oxalic acid and other substances, and at the same time it also produce color groups. |
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