Study On Volume-activated Carbon Fiber Electrode Of Electric Adsorption Desalination

At present, our country’s freshwater resources are very scarce and distribution is very uneven. The salinity of tail water that Chemical industrial park sewage treatment plant product is relatively high, it can’t achieve the reuse standard, in order to solve this problem, we study the desalination project. Among them, sea water and brackish water desalination use the principle of desalination. Traditional desalination include ion exchange, distillation, reverse osmosis, electrode analysis and so on. Because high cost and secondary pollution problems hinder its development, Electric adsorption desalination technology use charged electrode surface under the action of external electric field to adsorb ions and charged particles. So the ions in the water and the charged particles enrich in the electrode surface, then realize water desalination. Electric adsorption is a kind of new desalination method in recent years, with no secondary pollution, low cost, simple operation and maintenance. So this topic using electric adsorption technology research remove the salt.This paper use activated carbon fiber as electrode materials. It was carried out by the following experimental study:using single-factor and orthogonal analysis method to study the influencing factors of activated carbon fiber electrode of electric adsorption desalination, including the plate electrode spacing voltage, initial concentration of solution, solution volume ratio and water velocity. At the same time using the parameters to modify activated carbon fibers by nitric acid dipping and microwave method in order to strengthen the result of desalination; Studying the adsorption effect of cation and anion, under the different voltage, study the ion adsorption isothermal equation and adsorption isothermal curve; Studying the effect of ion adsorption under different number of electrodes, study water production rate in the case of three electrodes in series. The experiment can gain the following conclusions:Through single-factor and orthogonal analysis method, the experimental results showed that:Within a certain range, the bigger the voltage, the smaller the plate electrode spacing, the smaller the water velocity, the smaller the solution volume ratio and initial concentration of solution, the better the electric adsorption effect is. Through the experiment the best parameters values:voltage of 2V, the water velocity is 10ml/min, the initial concentration of solution is 500mg/L, the solution volume ratio is 40mL/g, the electrode spacing is lmm, when the electrode spacing is lmm, the influence order of various factors on the experiment is: concentration, volume, volume ratio and velocity.The electrode were modified by nitric acid dipping and microwave method. Test results show that the adsorption capacity of modified activated carbon fiber increased 0.5mg/g, than before modification. And nitric acid dipping modification effect is better than microwave modification. The influence order of various factors on the nitric acid dipping orthogonal experiment is volume percentage of nitrate, activated carbon fiber soaking time in the nitric acid, the temperature of the oven setting.The different valence of cation and anion experiment result showed that when the text conditions be same, the smaller the cationic radius and the more charge, the better adsorption effect is. The greater the amount of adsorption is.The experiment studied the activated carbon fiber adsorption performance, Test results show that the ion adsorption on activated carbon fiber not only accord with the Langmuir adsorption isotherm regular but also accord with the Freundlich adsorption isotherm regular.From several electrodes connected together, By the test results can be seen that several electrodes connected together can improve the adsorption rate, reduces the water electrical conductivity, However, with the increase of logarithm series, the weight of the activated carbon fiber will be double than before. The adsorption of each pair of electrodes will be decreased. Electrode adsorption ability has not been fully utilized. From three pairs of electrodes series test, we can know that water production rate will be about 70%.