| In recent years, the water quality of drinking water sources in our country has been polluted to varying degrees. The conventional water treatment process has limited removal ability to the micro-pollutants. And filtration is the last barrier of the conventional water treatment process. Without changing process conditions, the surface modification of the filter material can not only strengthen the filtering effect, but also not lead to the complex process of water treatment. Therefore, studying a new type of modified filter material is the main content of this paper.The Fe/Cu oxide composite modified quartz sand (OCMS) is prepared with raw quartz sands as the raw material to be coated FeCl3 and CUSO4 with the microwave. The effects of different preparation factors on the evaluating indexes of OCMS were studied by using humic acid removal rate, surface metal loading and desorption rate as the evaluating indexes. These factors include dosage ratio of FeCl3, CUSO4, deposition time t1, microwave time t2 and microwave power Q, etc. The optimum preparation conditions are obtained. The effects of different reaction conditions on the removal of humic acid and phosphorus from micro-polluted water by OCMS were investigated.The experiment results of preparing OCMS indicated that C1 and Q has a great influence on the removal rate of humic acid and desorption rate, t1 has the greatest impact on the amount of metal load, C2 is the least influence on the three evaluation indexes. The best preparation condition is:C1=0.16ml/g RQS, C2=0.07ml/g RQS, t1=12h, t2=1.5h, Q=800W.The surface of OCMS is rough, its shape is similar to snowflake and it has a large number of pores. The specific surface area is 0.959m2/g, which is 8.96 times of RQS.The Fe element in OCMS is accounted for 28.20%, the O element is accounted for 25.66%, Cu is accounted for 20.58%, and Si is accounted for 0.43%. The surface material compositions are mainly Fe2O3 and CuO, no SiO2 exposed, crystallinity is good and modified effect is significant. Fe3O2 and CuO can increase the positively charged of quartz sand, making OCMS have good adsorption effect on negative valence of organic pollutants in water.OCMS has a good effect on the removal of humic acid and phosphorus. In the neutral condition, the removal efficiency is the best, the removal rate is 93.1% and 84.95%, respectively; In acid or alkaline condition, the removal rate of humic acid is lower than 80%, and the average removal rate of phosphorus is below 60%.Different concentrations of phosphorus (2mg/L-20mg/L) in the initial adsorption, the removal rate remained above 80%, with the extension of adsorption time, phosphorus concentration increased, the removal rate decreased faster.The removal rate of humic acid and phosphorus can be fitted with a quasi-two level kinetic equation, both in 150min and 120min reached adsorption equilibrium. Adsorption rate equation, correlation coefficients and parameters are as follows:humic acid: y= 6.9937x+1.062, R2= 0.9997, K2= 46.056g/(mg·min), Qe= 0.143mg/g; phosphorus: y= 15.607x+988.37, R2= 0.9659, K2= 1.6458g/(mg·min), Qe=0.051mg g.The adsorption process of humic acid and phosphorus by OCMS can be described by Langmuir and Freundlich adsorption isotherm (correlation coefficient R2 is greater than 0.95). Adsorption characteristics of humic acid and phosphorus were more in line with the Freundlich adsorption model, correlation coefficients were:humic acid: R2Freundich=0-9823> R2Langunudr=0.9559 and phosphorus:R2Frewdich=0.9786> R2Langmuir=0.9572, adsorption models are multi molecular layer adsorption. |
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