Regeneration method of activated carbon
1. ultrasonic regeneration method
The activated carbon ultrasonic regeneration method applies energy to the adsorption surface of the activated carbon so that the adsorbed material is sufficiently removed from the adsorbed surface and is returned to the solution. The most important feature of ultrasonic regeneration is that the energy is applied only locally, without the need to heat a large amount of water and activated carbon, so the energy applied is very small.
2. electrochemical regeneration method
Electrochemical regeneration of activated carbon is filled between the two main electrode in the electrolyte, to activated carbon in DC electric field, electric field polarization, one end of the anode, the other end is cathode, the formation of micro electrolysis, respectively. Oxidation and reduction reaction in the cathode and the anode part of activated carbon parts the adsorption of pollutants on activated carbon and therefore most decomposition, small part due to electrophoresis force desorption. Electrochemical method is characterized by low energy consumption, limited processing object, perfect process, and can avoid two pollution.
3. supercritical fluid regeneration method
Supercritical fluid regeneration in the vicinity of the critical point CO2, sulfanilic acid, the optimum temperature of CO2 supercritical fluid regeneration method for 308K, when temperature exceeds 308K, the regeneration is not affected; when the flow rate is greater than 1.47 * 10-4m/s, the velocity does not affect the regeneration; with HCl treatment, the regeneration effect the activated carbon was obviously improved. For benzene, the regeneration efficiency decreases with the decrease of temperature at low pressure; the optimum regeneration temperature at 16.0MPa pressure is 318K; at the experimental flow rate, the regeneration efficiency increases with the increase of flow rate. The regeneration of supercritical fluid is characterized by a great change in regeneration efficiency. The regeneration time of activated carbon without drying should be extended.
4. solvent regeneration method
Solvent regeneration method is the use of activated carbon, solvent and adsorbate between the three phase equilibrium relationship, by changing the temperature, pH value of solvents and other conditions to break the adsorption balance, the adsorbate from the activated carbon off.
Two. Traditional activated carbon regeneration
1. oxidation regeneration method
Regeneration is the name of wet oxidation is in high temperature and high pressure conditions (general temperature of 230 DEG C) with oxygen or air as oxidant in organic oxidation activated carbon adsorption liquid phase on the decomposition into small molecules.
2. heat regeneration method
The heat regeneration method is divided into three stages: drying, high temperature carbonization and activation.
In the drying stage, the volatile constituents of the activated carbon are removed. High temperature carbonization stage is made of activated carbon on adsorption part of organic matter, boiling vaporization desorption, a part of the organic matter decomposition reaction, generate small molecule hydrocarbon desorbed, the residual component in activated carbon pores become "fixed carbon". At this stage, the temperature will reach 800~900 degrees C, in order to avoid the oxidation of activated carbon, usually in a vacuum or inert atmosphere. In the next activation stage, the CO2, CO, H2 or water vapor is injected into the reactor to clean the activated carbon pores to restore the adsorption performance.
3. biological regeneration method
Biological regeneration is the process of analyzing organic compounds adsorbed on activated carbon by using domesticated bacteria and digesting them into H2O and CO2.
The traditional regeneration technology of activated carbon has three shortcomings: 1) during the regeneration of activated carbon loss is larger; (2) the regenerated activated carbon adsorption capacity decreases obviously; (3) gas regeneration may produce two times of air pollution.