Preparation Of Nanocomposites Zirconium Dioxide-rGO And Its Phosphorus Adsorption Capability

Phosphorous is one of the key nutrients causing water eutrophication. Removing phosphorous in wastewater is important for water eutrophication countermeasure. Because of the lamellar mesoporous structure, high specific surface area, and stable chemical character, nano-zirconia particles(nano-ZrO2), which are nontoxicity, as the phosphorus adsorbent have attracted much attention in recent years. However, the application of nano-ZrO2 may cause secondary pollution because of its poor settleability. Graphene oxide(GO), anovel material with high surface area, good stability, and adsorption capacity, is a good carrier of adsorption material. The combination of The combination of nano-ZrO2 with GO can effectively increase the specific surface area,the adsorption capacity of phosphorus and reinforce the settleability. In this study, ZrO2-rGO composite material was prepared by hydrothermal method and characterized by XRD, FTIR, XPS, TEM and so on. In addition, the phosphorous adsorporation ability and influence factors of the as-prepared material were investigated. The main contents and results are as follows:1) Graphene oxide dispersion solution was prepared by using improved Hummers method. Then GO dispersions and a commercial nano-ZrO2 was used to prepare the mesoporous ZrO2-rGO nanocomposites through hydrothermal method. According to detected results through FTIR spectrum and SEM, the hydroxyl numbers of graphene surface decreased after the hydrothermal treatment, suggesting that graphene oxide was converted to reduced graphene oxide(rGO). The EDX and SEM analysis showed that(1) Zirconia can homogeneously dispersed on the surface of rGO and form hetero-junction with graphene;(2) Surface group of ZrO2 might provide rich reaction binding sites for mutual material compound to form nanocomposite ZrO2-rGO.2) The phosphorus adsorption ability of nanocomposite ZrO2-rGO in aqueous was studied. Furthermore, the effects of pH, ionic strength and accompanying ions on absorption were investigated. The results showed a high-performance of ZrO2-rGO on TP removal. When the zirconium content of ZrO2-rGO composite materials is normalization to that of nano-ZrO2, the phosphorus adsorption capacity of ZrO2-rGO(100 mg P/g) is much higher than the that of Zr O2(15 mg P/g). The phosphorus adsorption capacity of the composite materials is high when the pH value is 2-6, while it decrease with pH increasing. With the increasing concentration(0-0.5 M), the phosphorus adsorption capacity of the composite materials have the tendency of increasing. However, the co-existing ions of Cl-, SO42-, HCO3- have little influence on phosphate adsorption.3) The removal of TP, TN, NH3-N and CODMn of a typical sewage by ZrO2-rGO was studied. Result shows that ZrO2-rGO has remarkable absorption efficacy on TP in the sewage. At the same time, a desirable removal of TN,NH3-N and CODMn was observed, with highest absorption rate are 76.0% 、 25.3% 、 35.7% and 77.8%, respectively. In addition, the ZrO2-rGO adsorption-desorption cycle experimental results demonstrate that after 5~6 cycles, the adsorption ability of ZrO2-rGO on TP, TN, NH3-N, CODMn in water remains stable.These results show that ZrO2-rGO composite materials can effectively remove phosphorus in water, and after several adsorption-desorption cycles, the material still remains stable adsorption capacity, which makes the as-prepared material an ideal environmental pollutants adsorbent.