| 摘要 |
<p>A method for optionally removing hexavalent chromium(Cr(VI)) only from a chromium-containing waste solution or recycling the removed hexavalent chromium(Cr(VI)) is provided to prevent secondary pollution due to use of chemicals such as a reducing agent and solve problems such as excessive treatment time and manpower due to re-treatment of the chemicals. A method for modifying a surface of aluminum oxide comprises the steps of: mixing a mixed solution in which a mass ratio of aluminum chloride, aluminum nitride and aluminum sulfide is 0.05 to 1:0.5 to 3:0.01 to 0.3, and of which the total salt concentration is 0.1 to 5 (w/v)% with aluminum oxide in a mass ratio of 100 to 300:10 to 100; and drying the aluminum oxide at a temperature of 50 to 250 deg.C for 1 to 5 hours. A method for separating hexavalent chromium(Cr(VI)) from a chromium-containing waste solution comprises the steps of: mixing the surface-modified aluminum oxide with the chromium-containing waste solution to adsorb hexavalent chromium(Cr(VI)) onto the surface-modified aluminum oxide; and adjusting a pH of the hexavalent chromium adsorbed aluminum oxide to 2 or less using an acid solution to desorb hexavalent chromium(Cr(VI)) from the aluminum oxide.</p> |
