| For the past few years,as persistent pollutants in the environment,polycyclic aromatic hydrocarbons and heavy metals widely exist in various environmental system,especially in kinds of water environments.As we all know,polycyclic aromatic hydrocarbons and heavy metals are toxic,and the recent researchshave shown that when polycyclic aromatic hydrocarbons and heavy metals coexisted in the environment,the characteristics of combined pollution is produced.As for the combined pollution,as well as the resulting environmental effects attractsmore and more extensive attention.In view of the pyrene(PAHs)and co-exist heavy metalcopper in water,the mesoporous silica materials with functional groups were prepared by incorporation and modification methods.The mesoporous silica materials were then used to adsorb pyrene and copper from water.The adsorption behavior,process and adsorption mechanism were investigated.And themain conclusions are showed as following:(1)Two silica materials SBA15 and MCM-41 were successfully synthesized,and to study the removal capabilityof pyrene and copper in water.The results show that the adsorption of pyrene and copper on SBA15 and MCM-41 wereall fast,and the adsorption kinetics fitted the pseudo-second-order model perfectly;moreover,the Langmuir model fitted the adsorption better,that is mean the adsorption were probably monolayer molecularadsorption.The solution pH effects the adsorptionof pyrene and copper immensely,meanwhile the outer-sphere surface complexes were formed between the adsorbents and adsorbates.The adsorption of pyrene and copper onto SBA15 are mutual inhibited,while on MCM-41 are synergistic effects;in order to efficiently removingthe two pollutants,MCM-41 maybe a great choice,but the silica material has many shortcomings,such as poor thermal and hydrothermal stability,expensive templating reagent,etc.Therefore,we choose SBA15 to modified.(2)Fe and Mn was incorporated into the mesoporous silica framework of SBA15 respectively to synthesized Fe-SBA15 and Mn-SBA15.The two materials are still typical mesoporous adsorbent,and further study theadsorption capability of pyrene and copper.The results showed that the adsorption of pyreneand copper on Fe-SBA15 and Mn-SBA15 were fast,and adsorption kinetics fitted the pseudo-second-order model completely.The solution p H effects the adsorptionof pyrene and copper greatly,when pH increased,the adsorption capacity of pyrenedecreased while the adsorption capacity of copper increased.The maximum sorption capacity on Fe-SBA15 to be 0.161mg/g and 6.77mg/g for pyreneand copper,respectively;meanwhile,the maximum sorption capacity on Mn-SBA15 to be 0.091mg/g and 25.35mg/g for pyreneand copper,respectively.The ionic strength had big effect on the adsorption of pyrene and copper,that is the adsorption capacity of pyrene increased with the ionic strength increased,and the adsorption capacity of copperdecreased with the ionic strength increased.The adsorption of pyrene and copper onto the silica materials are synergistic effects.(3)The bimetallic adsorbent Fe/Mn-SBA15 was synthesized by hydrothermal,similarly,Fe and Mn were successfullyincorporated into the mesoporous silica framework of SBA15,and the adsorbent preserved the mesoporousstructural order after the functionalization.The adsorption of pyreneand copper on Fe/Mn-SBA15 was fast,and adsorption kinetics fitted the pseudo-second-order model completely.The maximum sorption capacity to be 0.170mg/g and 15.29mg/g for pyreneand copper,respectively.Pyrene and copper can promote each other to adsorb onto Fe/Mn-SBA15,and there is also a marked increase in adsorption rate.Pyrene andcopper on the adsorbent were complexed,and increasing adsorption of pyrene andcopper on the adsorbent could be attributed to the different adsorption sites.The solution pH effects the adsorptionof pyrene and copper greatly,and theouter-sphere surface complexes wereformed between the adsorbent and adsorbates.In a word,Fe/Mn-SBA15 could collaboratively and efficiently remove pyrene and copper. |
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