Study On The Preparation Process Optimization And Adsorption Characteristic Of Metallic Oxide Composite Modified Quartz Sand

Conventional water treatment process is difficult to remove micro pollutants. Meanwhile, filtration is the last barrier of this process. One of the important factors of the influence of effluent quality is adsorption and interception on the surface of the filter. The metallic oxide composite modified quartz sand (MCMS) is prepared with raw quartz sands (RQS) as the surface modification material, FeCl3, AlCl3 and ethanol solution of TiCl4 as the modifiers, surface loading, adherent strength and organic matter removal as the evaluating indicators by using the orthogonal test method and continuity test method, effects of micro pollutant adsorption and interception had been improved. Test results are as follow:(1) The preparation method is obtained. First, take FeCh to modify RQS for the first time. When the layer of iron oxide coated on the surface of RQS, take the compound modifier of intermixture of a certain proportion of AlCl3 and ethanol solution of TiCl4 to modify the layer of iron oxide for the second time.(2) The optimum preparation conditions are obtained by the method of SEM and EDS detection. The optimal dosage ratios of FeCl3 (2mol·L-1), AlCl3 (2mol·L-1) and TiCl4 (2mol·L-1) is 0.16 mL·g-1, 0.10mL·g-1 and 0.03 mL·g-1, calcination temperature is 240 ℃ and calcination time is 2 hours. Surface loading of all the metal on MCMS is 934mg/g, modifiers adhesive rate has reached to 97.04%, and organic matter removal of MCMS has reached to 98.67%.(3) By using the morphological properties analysis and semi-quantitative analysis method by EDS, surface characteristic of MCMS had been observed as little ball shape, metal crystal is uniformly covered on the surface of the carrier, help the MCMS more stability, and with a large specific surface area.The composition of the surface metallic oxide are analyzed which consisted of Fe2O3, TiO2, Al2O3, SiO2 and FeO(OH) or AlO(OH). The result of BET test shows the specific surface area of MCMS is 39.10 times as RQS and 3.38 times as IOCS. The combination of metallic oxide which produces a large number of hydroxyl is α-Fe2O3, AIO(OH) and Anatase TiO2 by the detection of phase identification from XRD. Organic matter removal of MCMS is 1.5 times as IOCS.(4) The average of HA removal of MCMS can reach to 91.56%.When the concentration of HA is 11.29 mg/L, the HA removal of MCMS can reach to 97.25%. The result of fitting with the adsorption characteristics of MCMS and the adsorption isotherm of Langmuir and Freundlich shows the adsorption characteristics of MCMS is both physical adsorption and chemical adsorption, meanwhile being based on chemical adsorption.