Synthesis And Properties Of Graphene Oxide And Iron Oxide Composite Adsorbent

Water eutrophication is becoming more and more serious. To solve this problem, excellent phosphorus adsorbents were studied and graphene oxide-iron oxide composite adsorbent was synthesized in this thesis. The effects of reaction conditions on morphology were investigated and adsorption-desorption mechanisms were explored.Iron oxide and GOIron oxide were synthesized by investigating the effects of GO, FeCl3.6H2O as iron source, pH controlled by NaOH and dropping precipitation. With FeCl3dropping rate5mL/min, pH3.2and PVP as disperant, the composites had a neat appearance and good dispersion, The thickness was about50nm, and the specific surface area was113.66m2/g, greater than74.65m2/g of iron oxide.Both adsorbents were calcined at150℃for3hours. Under conditions of C(KH2PO4)=20mg/L, V=100mL, m(adsorbent)=0.10g and t=35℃, adsorption equilibrium of the composites was reached after6h and the equilibrium adsorption capacity was14.39mg/g, much higher than7.94mg/g of iron oxide. Both materials adsorbed maximum amountof phosphorus at pH=3. Adsorption process accorded with McKay model and adsorption isotherm conformed with Freundlich model. Desorption equilibrium of the composites was reached after3h, and the desorption rate was over97%in4g/L NaOH solution. Repeated use had little effect on desorption rate, but obvious effect on decreased activation. After repeated use for4times, the equilibrium adsorption capacity decreased from14.39mg/g to10.22mg/g, desorption rate decreased from97.6%to95.3%.To sum up, GO-Iron oxide composite adsorbent had a large surface area, simple preparation method and was easy to be recycled. It would have a good prospect in water treatment field.