| 摘要 |
<p>Provided is a wastewater treatment method for selectively removing manganese from sulfuric acid acidified wastewater containing aluminum, magnesium, and manganese. The wastewater treatment method is to control precipitation of magnesium from the sulfuric acid acidified wastewater containing aluminum, magnesium, and manganeseso as to obtain demanganized wastewater, through a step wherein an acid or an alkali is added to sulfuric acid acidified wastewater to adjust pH to not less than 4.0 and not more than 6.0, whereby the sulfuric acid acidified wastewater is separated into a dealuminized solution and an aluminum precipitate; a step wherein a slurrying solution is added to the aluminum precipitate to form a slurry, then an alkali is added to adjust pH to not less than 9.0 and not more than 9.5, whereby an pH-adjusted aluminum precipitate slurry is formed; a step wherein an alkali is added to the dealuminized solution to adjust pH to not less than 8.0 and not more than 9.0, then an oxidizing agent is added to perform oxidation neutralization, whereby an oxidized and neutralized slurry is formed; and a step wherein the aluminum precipitate slurry and the oxidized and neutralized slurry are solid-liquid separated.</p> |
