Wastewater treatment method from steel mill cold rolling factory

摘要

The present invention relates to a method of treating wastewater generated in a cold rolling mill, wherein wastewater is equalized by mixing wastewater containing acid heavy metals into mixed wastewater containing oil-containing waste, alkali-containing wastewater, Sulfuric acid and calcium hydroxide as well as thioxanone ions contained in mixed wastewater COD and desulfurization wastewater are stabilized before they are introduced into the aeration tank to thereby effectively and stably treat contaminants by the microorganisms in the aeration tank. It has its purpose.;The present invention relates to a method for treating wastewater generated in a cold-rolling mill, comprising the steps of: thoroughly mixing an oil-containing wastewater, an alkali-containing wastewater, a desulfurization wastewater and an organic-Mixing the mixed wastewater with acid heavy metal-containing wastewater to adjust the thiosian concentration in the mixed wastewater to be 300 mg / liter or less; Neutralizing the pH of the wastewater to 6.5-8.0 by adding sulfuric acid to the wastewater to which thiocyanate concentration has been adjusted; Adding a coagulant to the neutralized wastewater to remove oil and suspended matter; And a step of oxidizing, absorbing, and adsorbing wastewater from which oil and suspended matters have been removed by microorganisms in the aeration tank, thereby treating wastewater generated in a cold rolling mill of a steel mill.