Study On The Preparation Of Granular Material Made Of (Base On) Attapulgite And Its Adsorption To Pb(?) In Aqueous Solution

Granular attapulgite and 13 X molecular sieve/attapulgite composite material were prepared by using attapulgite powder and 13 X molecular sieve as raw material.Calcination at high temperature was adopted to complete heat activation and the enhancement of strength at one-step.The effects of calcination temperature on the crystal structure,morphology,specific area and pore volume of both material,as well as on the adsorption capacity of material to Pb???in aqueous solution were investigated.Column tests were conducted by using granular materials prepared at appropriate temperature as fillers and the adsorption and enrichment mechanism of Pb???by granular materials was investigated.In addition,the effects of Pb???concentration and hydraulic loading on its breakthrough time were explored.The results showed that the appropriate calcination temperature of granular attapulgite was 650-750?,the pore volume and adsorption capacity of granular attapulgite were improved.The appropriate calcination temperature of granular 13 X molecular sieve/attapulgite was 600-700?,the specific area and pore volume of the composite material were increased.The adsorption isotherms of granular attapulgite and 13 X molecular sieve/attapulgite composite material conformed to the Langmuir isothermal adsorption equation.The fitting results revealed that the saturated adsorption capacity was 123.5 mg/g and 454.6 mg/g,respectively.The column test results showed that the adsorption of Pb²⁺ of granular materials was achieved by neutralization and sedimentation,surface adsorption,ion exchange adsorption and filtration interception.When the concentration of Pb???in influent was 20 mg/L,the breakthrough and saturation time of granular attapulgite and 13 X molecular sieve/attapulgite was 80 h and 185 h,160 h and 240 h,respectively.Lead in saturated granular attapulgite and 13 X molecular sieve/attapulgite reached 14.23% and 39.66%,respectively,which can be recycled by separation and smelting techniques.