The Study On Diatomite To Adsorption Heavy Metal Ions In Wastewater

In the paper,the adsorption characteristics and mechanisms for the nature micropore material——diatomite to adsorb heavy metal ions(Cr3+,Pb2+,Cd2+,Cu2+) in wastewater(artifical)were studied in detail.The experimental result indicates the following. The main factors which influence on diatomite to heavy metal ions adsorption removal are effective composition (SiO2) in diatomite and quantity of diatomite,time of adsorption,adsorption temperature and pH value of solution.The higher the purity of diatomite is,the better adsorption removal to the heavy metal ions is.In some extent,the removal effect to the heavy metals is improved with increase in quantity of diatomite,time of adsorption,adsorption temperature and pH value,but it decreases with the initial concentration of heavy metal ions.The model of adsorption accords with Freundlich equition.Conditions of flocculating settling for the diatomite suspension which adsorbed heavy metal ions were explored.The adsorption combined with the flocculation was applied to treat mixed wastewater(Cr3+,Pb2+,Cd2+,Cu2+),which has good application effect. The deposed heavy metal ions concentrations reach(Cr3+,Pb2+,Cu2+) or approach (Cd2+)the national emission standard.The diatomite minal composition,microstructure,appearance and surface function group were investigated by means of chemical analysis,XRD,FTIR,DRIF and SEM.The result shows that the amorphous SiO2 is 60~65% in Chifeng diatomite,diatomite shell is a disk on which distributes many micropores,and that its surface covers a lot of affinity and binate hydroxyl groups.The content of SiO2 increases by 15.23% and 21.07% after Chifeng diatomite was purified with water and with acid.The effect of adsorption to heavy metal ions is better...