Preparation Of Modified Ceramic Filter And Study On Adsorption Performance

Water is the most important part of the living organisms and an important resource of all life including humans. However, with the progress of human society and the continuous development of industry, water pollution is more and more serious, which has led to the shortage of water resources and the deterioration of water quality. This caused great threat to the health of human beings and the development of the society. In the face of the new situation, the traditional water treatment process has been difficult to meet requirements of purifying water quality. How to improve the process and the existing water treatment equipment for the effluent water is one of the important research direction.In the present study, a kind of clay-fly ash sintered ceramic mediums produced by a company in Gansu province was used as the carrier and ferric chloride as modifying agent for the surface modification. The COD removal rate of the artificial wastewater was used as evaluation standard of the modification effect. Optimize the modification conditions, including pH value, modification agent concentration, sintering temperature, time and number of coating times.The optimal modification conditions were pH=3; FeCl3concentration of2mol/L; sintering temperature of650℃; sintering time of3hours and coating2times. The result showed that the specific surface area of the modified ceramic mediums is2.75times of the raw ceramic mediums. After modification, the number and volume of pore in the ceramic mediums had been increased, the results of X-ray diffraction show the oxidation film of the modified ceramic mediums surface was mainly composed by alpha Fe2O3also have a small amount of alpha FeOOH. The reaction conditions had great effect on the form of oxide crystals in surface of modified ceramic mediums. And oxide crystal morphology of modified ceramic mediums had great effect on the surface area and its adsorption performance. The study found that only in pH=3, modification agent concentration of2mol/L, sintering temperature of650℃-750℃, sintering time is3h the crystals formed spherulitic crystal structure of the uniform size. Accumulation of these small balls to form three-dimensional structure and a large number of porous on the surface, this can effectively increase the surface area and the adsorption performance.The modified ceramic medium was used to adsorb humic acid. The results show that the adsorption performance of ceramic mediums for humic acid has been greatly improved through the modification. The adsorption conditions were optimized, including pH values, concussion time, adsorbent dose, temperature and concentration of salt. We found that only in the condition of pH=11.0, temperature of35℃, concussion time of6h, absorbent dose for7g/100mL and NaCl concentration of0.12mol/L that the removal rate of humic acid get the peak value of62.01%. The isotherm of adsorption of modified ceramic mediums to humic acid was fit with Freundlich model well. The dynamics research shows that:the modified ceramic mediums for humic acid adsorption process fit pseudo-second-order kinetic model more appropriately.