| The water pollut ion by heavy meta l ions has become the ser ious t hreat to the huma n healt h,living resources,ecologica l systems and the sustainable developme nt of socia l economy.How to effective ly remo ve the hea vy meta ls in aqueous so lu t ion has been attracted great attent ion b y researchers and t he gover nments around the word.In this work,us ing graphe ne oxide loaded Fe3O4 nanopartic les as carriers,magnet ic graphene oxide gra fted different hydrophobic cha in le ngth a nd end groups dendr imers used for adsorption of hea vy metal ions in aqueous solut io n were fabricated by diver gent method and magnet ic separatio n techno logy.?1?First ly,the hexa met hyle nedia mine?HMD?modified ma gnet ic graphene oxide?HMGO-N H2?was prepared by solvother ma l method,then us ing HMGO-N H2 as carr ier,hexa methyle nedia min and met hyl acrylate?MA?as funct ion mono mers,magnet ic graphene oxide grafted longer hydrophobic chain lengt h low-generat ion hexa methylened ia mine t ype polyamidoa mine dendr imer?HMGO-PAMAM-G1.0?was fabricated by divergent met hod and magnet ic separation technolo gy.The morpholo gy,structure and compos it ion o f the sa mp les were characterized by trans miss ion e lectron microscope?TEM?,X-ray diffract ion?X RD?,Fourier trans for m infrar ed spectrometer?FT-IR?,N2 adsorption/desorption isother m,thermo gravimetr ic analyzer?TG A?,vibrating samp le magnetometer?VSM?and X-ray photoelectron spectrometer?XPS?.The adsorpt ion propert ies of MGO-PAMAM-G1.0 and HMGO-PAMAM-G1.0 for Pb?II?and Hg?II?in s ingle s ystem were studied by batch experime nts.The adsorption experiment data of MGO-PAMAM-G1.0 and HMGO-PAMAM-G1.0 for Pb?II?and Hg?II?were obtained by us ing k inet ic models and isother m models.The results showed that the superparamagnet ic HMGO-PAMAM-G1.0 was successfully prepared.The specific saturat ion magnet izat io n of HMGO-PAMAM-G1.0 was 25.9 emu·g-1,which can be quick ly separated fro m aqueous solut ion under externa l magnet ic fie ld.Compared w ith MGO-PAMAM-G1.0,HMGO-PAMAM-G1.0 had a lar ger average poresize and a sma ller BET specific sur face area,higher adsorptio n rate and lower adsorption capacit ies for Pb?II?and Hg?II?.The adsorptio n processes of MGO-PAMAM-G1.0 and HMGO-PAMAM-G1.0 for Pb?II?and Hg?II?could be described by the pseudo-first-order kinet ic model and Langmuir isother m model.The analys is of XPS indicated that vale nce state of Pb?II?didn't change,Hg?II?was part ially reduced to Hg?I?in the adsorptio n process.?2?The terminal groups of a series of magnet ic graphene oxide grafted polya midoamine dendrimers?MGO-PAMAM?were mod ified w ith chlorohydrin to fabricate magnet ic graphene oxide grafted hydroxyl-terminated polya midoamine dendr imers?MGO-PAMAM-O H?.MGO-PAMAM-O H for the adsorption of Hg?II?in aqueous solut ion was characterized by transmiss ion e lectron microscope?TEM?,X-ray diffractio n?XRD?,Four ier transfor m infrared spectrometer?FT-IR?,ele menta l analys is,ther mogra vimetr ic ana lyzer?TG A?,vibrat ing sa mple ma gneto meter?VSM?and X-ray photoelectron spectrometer?XPS?.The results s howed that ma gnet ic graphene oxide gra fted 3.0 generatio n hydroxyl-terminated polya midoamine dendr imers?MGO-PAMAM-O H-G3.0?had better adsorpt ion property,and the maximum adsorptio n capacit y was 129.98 mg·g-1.The adsorptio n process of MGO-PAMAM-O H-G3.0 for H g?II?could be better described by the pseudo–first-order kinet ic model and Langmuir isother ma l adsorptio n model,whic h indicated the adsorption was s ingle la yer che mical adsorptio n on homo geneous surface. |
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