Research On Adsorption Properties Of LDHs/Montmorillonite Composites For Phosphate Ion

Extensive anion pollutants in water pose a serious threat to the environment and human health.Hydrotalcite compositess(LDHs) as a kind of cheap and recycled adsorptant has become a hot spot because of high adsorption rate,reuse and no secondary pollution.lt shows good adsorption property of anionic pollutants.Montmorillonite can also adsorb anion through bond-breaking.Rearches are more focused on adsorption behavior of anion with a single absorbent which has shortcomings of low adsorption quantity and limited applicable scope.So develoing inexpensive,highly-adsorbed and envionment-fiiendly composites to remove pollutant in water with the greatest degree.It posesses very important significance in LDHs reaserch.This subject designs and synthesizes Mg-Al LDHs,and characterizes the structure by XRD,IR and SEM, then preparating hydrotalcite/montmorillonite composites and inspecting the adsorption of PO‐3-in water.Results show that hydrotalcite/montmorillonite composites by using the high shear technology has better adsorption performance for PO4‐,which are important for dealing with water-eutrophication.Mg-Al LDHs are synthesized using the method of coprecipitation and the structure of adsorbtion is characterized by XRD.The results show that the preparated Mg-Al LDHs has a neat layer board stucture,the chemical groups are identified by IR.The results show that under the protection of N2the synthesized Mg-Al LDHs completely contains NO3-in the interlayer. SEM images the regular structure.Choosing PO3-for being adsorbed irons,the adsorption performance of Mg-Al LDHs for PO43-is investigated,then Langmuir and Freundlich isothermal equation are fitted,the capacity of saturation adsorptionis worked out according to isothermal adsorption equation.The results show that,under the experimental conditions,the isothermal adsorption data of LDHs for PO43-in water fits Langmuir model of the equation highly.Then by using the high shear technology,series of Mg-Al LDHs/montmorillonite composites are perparated,microstructure of composites is characterized by XRD and SEM,then the adsorption performance of the composites for PO43-in water is studied,Langmuir and Freundlich isothermal equation are fitted,the capacity of adsorption saturation is worked out according to isothermal adsorption equation.The result shows that,under the experimental conditions,the isothermal adsorption data of LDHs/montmorillonite composites composites for PO43‐in water fits Langmuir model of the equation highly.The possible adsorption mechanism of composites forPO43‐is investigated,the reason and influence factors of the synergy are analysized and the composites adsorption performance is regulated.Research shows series of LDHs/montmorillonte composites are perparated by using the high shear technology,pore volume increases,the average pore size increases,the adsorption is better,the adsortption capacity is greater than the single hydrotalcite,so LDHs/montmorillonite composites has good adsorption performance for PO43‐in water.lt is a very promising,efficient composites adsorbent.