The Study On Preparation And Filtration Properties Of Iron Chloride Coated Sand

The organic pollutants in the water will be changed into the carcinogenicdisinfectionbyproductsafter the chlorine disinfection. But the traditional water treatment can’tremove it effectively. So it is meaningful to enhance the filtration through the modifiedquartz sand mediums to remove the organic pollutants.Using the FeCl3to modified the quartz sand. Making the concentration,pH, sinteringtemperature and sintering time be the conditions of preparation. After the test, summedthe best conditions of reparation were FeCl3of2mol/L; pH=1; sintering temperatureof550℃; sintering time of2hours. The order of the influence factors of the preparationconditions were pH>concentration>sintering time>sintering temperature. The iron onthe modified mediums is positivelycorrelated with the absorption of the organicpollutants were found through the test of the iron content under different conditions ofpreparation.Product the modified mediums and use it to do the statictest. The result showedthat the iron content of the modified mediums were19.4mg/g. Putting the modifiedmediums into the circumstanceof mechanical agitationwith200r/min or the pH with3or4, found the expulsion rate of the iron were0.34%,0.43%,0.77%. Themodifiedmediums’ porosity were0.63which are bigger than the original quartz sandwhose porosity were0.46. The specific surface area of the modifiedmediums were2.43times the original quartz sand.The result of the SEM showed that there were manyhydrolysisof the ferric chloride polymers sediment on the surface of the modifiedmediums. The surface seemed to be not smooth, the polymer sediment on the surfacelook like the thick deposits. The adsorption capacity of the modified mediums also havebeen improved. The adsorption type of the modified mediums belongs to Langmuir andthe original ones belongs to Freundlich.When the filtration velocity improved, the two cartridges’filtration cycle reduced.But the modified mediums’cycle were longer when they were under the same velocity.The modified mediums showed a better capability on the filtrationthrough the result ofthe MSC and FPI. The removal rate of theorganic pollutants weredifferent in differentfiltration velocity and time.The modified mediums keep the removal rate about30%,and they were better when they were in the same velocity compared with the originalone. The modified mediums performed better in the remove of the organic pollutants in neutral or weakly acidic water. Themodified mediums also showed some effect on the remove of manganese. The modifiedmediums performed better in the remove of the manganese in neutral or weakly acidicwater. Back wash with water could resume the capability of the mediums on the removeof the suspended solids. But this way showed no effect on the remove of the organicpollutants until added the desorbent in the water.