The original granules (ceramic adsorbent before sintered) were
grayish yellow, while the ceramic adsorbents became brick-red
after treatment. The change was result from the high-temperature
calcination. The surface charges of the original granule (zeta potential
30.1 mV) and the ceramic particle (zeta potential 31.2 mV)
were not obviously changed. The surface areas of the original granule
and ceramic particle are shown in