The Research Of Modified Zeolite Eliminate Lead Ion In Wastewater

Lead is a kind of heavy metal element that harm severely human body, it produced pollution to the water body and influence seriously humanity normal life. At present, the containing lead ion wastewater has been processed by ion exchange method and chemistry precipitation method in domestic and foreign. The ion exchange technique has many merits comparing with other methods.The natural zeolite has performance of ion exchange, but ion exchange capacity of it is very small. So the natural zeolite isn't suit for the need of industrial production. The modified experiment of Che Tian zeolite is carried out by modifier in this article. And the ion exchange ability of Che Tian zeolite is increased. The experiment of this article indicates that modified effect of sodium chloride is better. The lead ion exchange capacity of modified zeolite is enhanced three times and can achieve 0.5135mmol/g. It is known by researching temperature and pH value to the influence of exchange experiment, sodium zeolite's exchange effect is best when the exchange solution temperature is 20℃and pH value is near neutral. The identical temperature ion exchange curve is drawed according to the exchange experiment datum of sodium zeolite and lead ion. It evidences that sodion has higher selectivity exchange ability to lead ion in zeolite. The reaction standard enthalpy change of exchange experiment is negative value by calculating in different temperature conditions. It evidences that the exchange reaction of sodion and lead ion which occur in zeolite is process of releasing heat, so the exchange experiment of sodium zeolite and lead ion is suited to carry on in low temperature condition. The result of exchange dynamics experiment evidences that when the used amount of zeolite and the volume of exchange solution are identical, the bigger initial density of exchange solution is, the shorter exchange balanced time is. It is known that exchange control mechanism of sodium zeolite and lead ion is particle diffusion control according to the indirect judgment law. Zeolite which is dealed with by three regeneration experiments may achieve 86.68% to exchange rate of lead ion, so the effect of recycling is better. The constant of dynamics model expressions which is obtained in this article is only approximate value, but the executing state of exchange reaction is forecasted simply by model expressions in the corresponding experiment condition.