| Eutrophication of landscape water has increasingly become a global water environment pollution. How to effectively control eutrophication and the generation of water-bloom have become the hot area of research for environmental protection. In this paper, zirconium load attapulgite(Zr-ATP) particle phosphorus adsorbent was prepared by impregnation method and forming technology, removing the phosphorus from the eutrophic water, reducing the phosphorus content, breaking the proportion of nitrogen and phosphorus in water, achieving the goal of landscape water body eutrophication finally. The best preparation conditions, phosphorus adsorption performance and mechanisms of the Zr-ATP granular adsorbent were mainly studied for the basic theory of phosphorus wastewater treatment and environmental composite adsorbent research.Related research shows that: the attapulgite is a kind of layer chain-like silicate with good adsorption performance, which has aquated magnesium and aluminum, with large specific surface area and pore structure. High-efficiency phosphorus adsorbent can be obtained by alkaline, acid and microwave modification, however, its adsorption capacity and rate still have room to improve. Zirconium has good adsorption, meanwhile, forming a tetramer in aqueous solution with strong adsorption of PO43- and F- anions in water. We can use zirconium load on attapulgite, enhancing its adsorption capacity and rate. However, powdery adsorbent difficult to apply in practical engineering, because its easy-lossing, difficult to recovering, difficult to separating, easy to jaming filter material and increasingly turbidity. To solve these problems, the related research has been carried out.The experimental results shown that: the best preparation conditions for Zr-ATP powded adsorbent was controlling concentration of zirconium solution, solid/liquid ratio, calcination temperature and aging time as 0.2 mol/L, 1/2, 100 ℃ and 12 h. At this point, the product obtained on phosphorus adsorption efficiency can be reached up to 99.9%, adsorption capacity of 9.99 mg/g(calculated based on phosphorus). XRD, FTIR and SEM results shown that the zirconium successfully loaded on attapulgite, existing in amorphous state at low temperature, an having no impact on structure of attapulgite. The powdery adsorbent was molded to granulation by the extrusion technology, as the results, the primary and secondary influence factors during the preparation of Zr-ATP adsorbent particles can be set as Na2 Si O3>PVA>Al2O3>S: L; the best preparation is that: Zr-ATP: Na2O3: α-Al2O3= 5: 1.6: 2.5 g,PVA(SA) 5 %(wt),S/L=3/3.5; the granular adsorbent has good erosion resistance and strong mechanical properties, particle average compressive strength can reach 57.32 kg/cm2.When the additive quantity of 4 g / 100 ml, at room temperature, p H of 1 ~ 5 range, Zr-ATP granular adsorbent has good adsorption efficiency for 20 mg/l simulation phosphorus wastewater, which can be reached up to 97%, the adsorption capacity can reach 7.5 mg/g. At the same time, the adsorbent has good adsorption efficiency for the water coexisting both nitrogen and phosphorus, phosphate removal efficiency is as high as 95%, the adsorption equilibrium time is 6 h; ammonia removal efficiency is as high as 79%, the adsorption equilibrium time was 10 h.For xi’an Xing Qing park and Laodong park, Zr-ATP granular adsorbent was used to treatmental test in the two lakes, after processing,there is no nitrogen and phosphorus can be detected in water body, which signifys that the adsorbent has high adsorption performance for nitrogens and phosphorus in landscape water. And it is a neotype eutrophication repair agent worth to in-depth study furtherly. |
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