Contained Benzene Activated Carbon By Microwave Irradiation Regeneration Methods

Takes the advantages of good opening structure and huge surface area, Activated carbon has excellent absorption capacity and had got wide application in industry. Since the first application of grain AC in industrial waste water treatment in 1970s,AC has got great development in terms of technique and has been employed for different purposes. Meanwhile, a lot of waste AC have been produced in the process of its application, it not only wastes resources, but pollutes the environment if it were not reclaimed and disposed correctly.As microwave heating takes advantages of instantaneous heating, good penetrate ability etc, a lot of researches have been carried out regarding the application of microwave in AC regeneration both at home and abroad. The paper studied the feasibility of benzene loaded AC regeneration with microwave, researched the influence of microwave radiation on the performance of AC, assessed the merits and defeats of the microwave regeneration technology, and discussed the mechanisms of AC regeneration by microwave radiation.The experiments on AC wastage and temperature increasing character show that: radiated by microwave, the temperature increasing velocity of AC is really swift, and can reach to high temperature; the temperature increasing performance of AC was influenced by the quantity of AC and microwave power, the temperature increasing velocity of AC accelerated with the increase of microwave power and AC quantity; the AC wastage was influenced by microwave power,quantity of AC,microwave radiation time and gas flux.The experiment on AC absorption capacity shows that: compared with fresh AC, the absorption capacity of regenerated AC (with microwave of 385W) declined, but it is not distinct, after the first regeneration, the absorption capacity of the regenerated AC equals 95% of that of fresh AC; the absorption character of fresh AC and regenerated AC(with microwave of 385W) are well matched with Freundlich equation; microwave heating takes influences on the absorption velocity of AC, but the influence is not eminent; the absorption character of AC have not changed after radiation by microwave.The experiment on benzene desorption shows that: in the process of regeneration of benzene loaded AC,the temperature of AC increased quickly, and the desorption rate of benzene loaded AC reached to 94% within little time in a definite condition. The microwave power,radiation time and the quantity ofAC have great influence on the desorption rate of saturated benzene loaded AC, the benzene desorption rate of AC increased with the increase of microwave power, radiation time and the quantity of AC, the gas flux have little influence on benzene desorption rate. Based on single factor experiment,the paper got the conclusion that desorption rate was influenced mostly by microwave radiation time, followed by microwave power,quantity of AC and gas flux in sequence. Based on orthogonal experiment, the best technology condition for AC regeneration is obtained as follows: 3g for the quantity of AC, 0.9L/min for gas flux,240s for radiation time and 539W for microwave power.For non-polar substances such as minerals,microwave heating was induced mostly by interface exhaustion and moving exhaustion form free electric charge, the transfer of microwave in medium is in conformity with the Maxwell equation. The fact that AC can absorb microwave power intensively is in close relationship with its structure and chemical compositions. The absorption of microwave by AC is induced mostly by the polar functions of electric charges. The mechanisms of regenerating AC benzene by microwave can be explained by container heating theory.