International Online Conferance On Engineering And Natural Sciences, Gümüşhane, Türkiye, 5 - 07 Temmuz 2021, ss.1-2
Recently,
heavy metal removal from wastewater works have gained importance. For this
purpose, in this study, Graphene supported CeO2 and ZrO2
adsorbents were synthesized to be used in the removal of some impurities from
wastewater. Three different preparation methods were used to synthesize CeO2-Gr,
ZrO2-Gr, CeO2-ZrO2-Gr adsorbents:
impregnation, hydrothermal and solvothermal methods. Adsorbents were
characterized by using X-ray diffaction analysis, N2 physisorption
measurements. The average crystal size of the catalysts were calculated using
the XRD analysis data by using the Debye Scherrer equation. According to
calculations, average crystal sizes range between 40.37Å and 164Å. The highest
mean crystal size was observed in the CeO2-ZrO2-Gr
adsorbent prepared by the impregnation method, the lowest in the CeO2-ZrO2
-Gr adsorbent prepared by the solvothermal method. When the methods were
compared, it was observed that the highest average crystal size was in the
adsorbents prepared by the impregnation method. By N2 physisorption
analysis; surface areas, average pore diameters, pore volumes and
adsorption-desorption isotherms were determined. The highest surface area was
calculated as 203.8 m2 / g in ZrO2-Gr adsorbent prepared
by hydrothermal method. Average pore diameters vary between 21.45 Å and 294.37
Å. The highest mean pore diameter was found in CeO2-ZrO2
–Gr adsorbent prepared by solvothermal method. Mesopore and micropore volume
were determined from the desorbed nitrogen gas volume value at the last point
of nitrogen adsorption/desorption isotherm. When we look at the values, it is
seen that the macroporous volume results are higher in adsorbents. In the
results we obtained, it was determined that the total volume of mesopores and
micropore volumes in adsorbents synthesized by solvothermal method is higher
than the catalysts prepared by other methods. It was observed that the total
pore volumes of the adsorbents obtained by the hydrothermal method were higher
than the total volumes of the catalysts prepared by other methods. When the
isotherm curves were examined, it was observed that all the synthesized
adsorbents fit Type 4.