八面体形tio2对砷的吸附和光催化氧化研究化学工程与技术专业论文.docxVIP

AbstractAbstract Abstract Abstract As an efficient，environmentally friendly,non—toxic absorbent material and photocatalytic material，Ti02 is widely used in the treatment of arsenic contamination of drinking water．Since pH value，the concentrations of the adsorbent and arsenic reaction- time，and the light source haye significant impact on the adsorption and catalytic of arsenic， it is necessary tO explore these factors and the adsorption and catalytic mechanism． In this work，Octahedral Ti02 nanocrystals(OTNs)with the main(1 0 1)surface have been prepared by hydrothermal method using the hexamethylenetetramine as the morphology controlling agent．XRD，SEM，BET was used for structural characterization． XRD results showed that all three were pure anatase phase．SEM results showed that anatase with(1 0 1)surface dispersed uniformly,uniform morphology,and the average size was 96．34nm．BET results showed that anatase with(1 0 1)surface specific surface was 1 7．6m2-g～．and there was lot of mesoporous the crystal surface．Anatase with (1 01)Surface was used tO adsorb As(III)and As(V)in the solution．When the arsenic concentration was O．2mg·L-1 and the OTNs concentration was 0．1 g·L-1，the adsorption reached equilibrium at pH 4，7，9 three solutions in 1 50min．Kinetic fitting results showed the adsorption behavior of As(III)and As(V)was more in line with false second-order equation，indicating chemical adsorption was dominant．Adsorption isotherm results showed that the adsorption was more in line with Langmiur adsorption isotherm model， adsorption capacity for As(III)and As(V)were 1．8930 mg。g～and 1．8566 mg。gq respectively．Total of 1 4 kinds of adsorption results with pH range from 1 to 1 3．5 showed that OTNs had good adsorption ability for As(III)at neutral and alkaline solutions and for As(V)at acidic solutions．At pH range from 1 tO 1 3 total of 1 3 kinds of uv photolysis results showed that OTNs could oxidize As(III)to As(V)within 3 0 min at pH range from 8 to 1 2．The adsorptions