| The water quality of steam condensation water matches that of the demineralized water, which is of great value to reuse. But for some reason, the equipment and pipeline of condensate system are often corroded, the corrosion products brought to the follow-up steam equipment such as turbine cause salt accumulated in super heater and turbine, which seriously affect the security and economic operation of the equipment. So finding a efficient and feasible way of removing the iron of condensation water is the key to the reuse of condensate. And activated carbon fiber adsorption method with simple operation, low equipment investment costs and energy consumption is a high efficient separation method. Activated carbon fiber has become the most promising adsorption material with the advantages of large specific surface area, developed porous, fast absorption and large adsorption capacity. Thus research for the adsorption and regeneration of iron in condensate by activated carbon fibers has practical applied value.Firstly, the influence factors, such as adsorption time, pH value of the solution and the specific surface area of ACF on the adsorption were studied and the adsorption isotherms were obtained by static adsorption experiment. The results showed that the adsorption process was composited of physical adsorption and chemical adsorption, and the adsorption capacity can be improved by increasing the surface area of ACF and the temperature of the reaction solution. The more basic groups the ACF surface has, the better for adsorption of ACF on Fe3+. Langmuir and Freundlich isothermal adsorption equations were used to fit the adsorption data, found that the adsorption of ACF on Fe3+is closer to the Langmuir adsorption model.Secondly, the breakthrough curves of dynamic adsorption in various experimental conditions were studied by a fixed bed, which was designed and made in this lab. The results showed that breakthrough curves and breakthrough time were affected by experiment conditions. In the dynamic adsorption process, the best quality of treated water was obtained when the flow rate is of10ml/min. Dynamic adsorption of ACF is more suitable for processing low concentration of iron ions in the solution.Finally, the regenerative process of the ACF was achieved using electric field and auxiliary regeneration which investigation on the influences of regeneration parameters such as regeneration time, voltage, the dosage of auxiliary agent and electrolyte concentration. At last, the regeneration mechanism was preliminary discussed. The results show that under the optimum conditions for120min, voltage for1100mv, auxiliary regenerating agent citric acid content for4.8%, sodium sulfate concentration for0.7mmol/L,303K, the ACF can reach the best regeneration effect and the regeneration rate is87.2%。which the specific surface area of ACF and sodium sulfate concentration effect on the regeneration rate is not obvious, but regenerative voltage and auxiliary agent are the key factors influencing on the regeneration rate. After regeneration for many times, the regeneration rate will decline, but still can keep above80%。 The surface morphology before and after regeneration were investigated by scanning electron microscopy (SEM), which found that regeneration will not do any damage to fiber。 The using and multiple recycling can be realized。... |
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