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Heavy metal contamination of soil and polluted water is very common in nature , a direct threat to human life and health and the entire ecosystem stability . In this paper, the assay is based on systematic analysis of a variety of factors ( reaction time , pH , temperature , soil water ratio , etc.) affect the next four heavy metals ions ( Cd , Cu , Pb , Zn ) in the three materials ( kaolin, natural calcium adsorption characteristics of bentonite and activated tree leaves ) , and by infrared spectroscopy , XRD diffraction pattern analysis of the adsorption reaction mechanism ; On this basis , the exploratory activation the Indus leaves and clay mineral bentonite blend of new composite materials and to test the adsorption properties of a series of meaningful conclusions . 1 ) as a silicate, aluminosilicate composed mainly of minerals, kaolin , bentonite adsorption surface complexation , adsorption type can be completed when the pH is lower ; magnesite in kaolin and muscovite pairs the adsorption of Pb ( II ) and Cu ( II ) is an important contributor ; 2) there are a large number of amino, carbonate and phosphate activation tree leaves are good keys can effectively adsorb heavy metals , heavy metals Cd ( II ) , Cu ( II ) , Pb ( II ) , Zn ( II ) adsorption made ??a great contribution ; quartz composition was first discovered in heavy metal ions Cd ( II ) adsorption plays an important role in the hydrolysis of silicic acid and Cd ( II ) binding flocculent insoluble to generate silicic acid cadmium thereof. 3 ) relative to the Freundlich model and DR model , kaolin , bentonite and the activation tree leaves adsorption Langmuir model is more accurate to describe the adsorption kinetics analysis found that activation of tree leaves in 40 minutes to be completed by the basic adsorption process , bentonite slightly slower takes about 3-4 hours , kaolin reaction usually requires more than 50 hours in order to achieve a balance . 4 ) activation of paulownia leaves - bentonite composite material is preferably a combination of bentonite and activated paulownia leaves advantages , the composite material has a lot of useful heavy metal adsorbing group include amino , carbonates and phosphates , wherein the bentonite network for heavy metals co- keys ; the composite adsorption of heavy metals are usually completed within a few hours , and acidic conditions could be reached about 85 % of the amount of heavy metal removal , showing good prospects for industrial application .
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