Wastewater treatment method to reduce fluorine and chromium hexavalent ions in wastewater

摘要

The present invention is a stainless steel making process or to etc. Various plating process using a hydrofluoric acid reagent or a fluorine compound, a chromium ore, chromium-containing compound such as a fluoride ion (F ^-) contained in industrial waste water generated in the process of making the product (s) and chromium (Cr ^{+ 6} ) A method for treating wastewater to remove or reduce ions and discharge to a level lower than the specified level in the Environmental Conservation Act.;Waste water treatment method of the present invention, the composition 100㎖ during manufacture, calcium carbonate (CaCO _3): 0.50-1.00g, lithium carbonate (LiCO _3): 0.10-0.30g, sodium bisulfite (NaHSO _3): 0.05-0.20g, acetic acid _{(CH 3 COOH) (1 +} 1): 25-50㎖, the rest is removed by precipitation of the fluoride added to the composition composed of the reducing reaction tank and water (H ₂ O) as a component in the insoluble fluorinated compound and the chromium Is converted from Cr ⁺⁶ to Cr ⁺³ to be easily removed in a neutralization tank and pH adjustment is facilitated; It is a technical point to remove or reduce fluorine ion (F ^- ) and chromium hexavalent ion (Cr ⁺ 6) in wastewater by adding 10-20% Na ₂ CO ₃ to the neutralization reaction tank.