Method for chromium removal from post-tanning wastewater

A method for chromium removal from post-tanning wastewater, comprising the following steps:

• (a) mixing pretreated post-tanning wastewater with an induction reagent to allow an induction reaction, wherein the induction reaction is conducted at 20° C. to 60° C. for 0.5 hours to 4 hours;
• and
• (b) adjusting a pH of a material obtained after the induction reaction to higher than 7.0 for precipitation;
• wherein the induction reagent comprises a soluble metal salt.

A method for chromium removal from post-tanning wastewater, comprising the following steps:

• (a) mixing pretreated post-tanning wastewater with an induction reagent to allow an induction reaction;
• and
• (b) adjusting a pH of a material obtained after the induction reaction to higher than 7.0 for precipitation:
• wherein the induction reagent comprises a soluble metal salt, and wherein a method of a pretreatment comprises:
• mixing post-tanning wastewater with a dye-fixing agent for a treatment, and subjecting a resulting mixture to a solid-liquid separation to collect a liquid.