Preparation Of Modified Illite And The Adsorption Characteristic To Pb²⁺

In the field of heavy metal wastewater treatment,clay mineral has been widely applied,Illite is a sort of typical clay minerals.Pingdingshan city is called center of illite,in yeying country,the reserves of illite are 1380 million ton. To improve the adsorption efficiency of illite,we put forward and explored a new modification methods which heating illite with Zn SO4·7H2O.Besides, taking the Simulated wastewater containing lead as the object, we study the adsorption speciality of illite and modified illite. The research content and results are as follows:(1) Zn-illite was prepared in a favouratebale way which mixed and heating illite and Zn SO4·7H2O.the best preparation condition is that keeping calcination temperature at 600℃, Zn SO4·7H2O/illite(mass ratio) in 1:2 and sintering time at 2.5 hours. The saturated adsorption capacity of Pb2+ in surface of Zn-illite reached 25mg/g,which was improved with amplitude of 100%.(2) Illite and Zn-illite were characterized by the way of DAT-TG,X-ray diffraction(XRD),SEM/EDS, Specific Surface Area(BET),Cation Exchange Capacity(CEC), Zeta- potential and so on.The result showed that:neither illite nor has not microporous structure. Process of modification wiped out water and –OH on surface of illite. Isothermal adsorption specific surface area of langmuir Falled to 10.99m2/g from 28.61 m2/g,EDS image showed that Zn element login in internal crystal framework or interlamination of illite;Zeta potential falled to-41.2m V from-28.9m V; Cation Exchange Capacity rised to 26.8mmol/100 g from 15.5mmol/100 g.(3) Influence of dosage 、temperature、p H、reaction time and other factor to adsorption efficiency of illite were re-searched in the paper, The result showed that, increasing dose and high p H promote adsorption.But increasing dosage reduced average adsorption capacity. When Pb2+ were all adsorpted, average adsorption capacity can reach 10.5mg/g. Adsorption thermodynamics process of Zn-illite matched langmuir isothermal model. The max single layer adsorption capacity reached 26.52mg/g. Adsorption Kinetic process matched secondary kinetic process. Adsorption rate constant reached 5.83mg/g·min in the condition of that original concentrate is 300mg/L. optimum temperapture and reaction time is 65℃ and 1.5h.(4) inorganic strong acid and saline solution was used as strippant to study desorption characteristics of illite and Zn-illite. The result showed that, hydrochloric acid has a high desorption efficence to illite and Zn-illite. Desorption efficence was influenced by concentration of acid and Pb2+, The highest desorption rate reached 92%,optimium acid concentration is 1.0mol/L.After 8 repeat use Adsorption capacity keep on 90% of original adsorption capacity of Zn-illite.