Treatment method and system for CIT heavy metal-containing sulfuric acid wastewater

Abstract

The invention provides a treatment method for CIT heavy metal-containing sulfuric acid wastewater. The treatment method comprises the following steps: (S1) adding lime slurry into wastewater to carry out neutralization reaction, so as to generate a calcium fluoride precipitate; (S2) adding ferrous sulfate into the wastewater, and supplying compressed gas into the wastewater to carry out aeration, so as to generate ferric iron, a ferric arsenate precipitate, a ferric arsenite precipitate and a flocculent precipitate; (S3) filtering the wastewater to remove the precipitates, so as to acquire filtrate; (S4) adding the ferrous sulfate into the filtrate, and supplying the compressed gas into the wastewater to carry out aeration, so as to generate precipitates; (S5) introducing carbon dioxide-containing compressed gas into the liquid obtained in the step (S4) to carry out aeration, so as to generate calcium carbonate crystals and decrease the stability of calcium sulfate; and (S6) adding an inorganic flocculant and PAM into the liquid obtained in the step (S5) to carry out coagulation reaction. According to the treatment method, the scaling of a reaction tank can be avoided, the treatment efficiency is high, and the operation is stable.

Description

technical field [0001] The invention relates to the technical field of wastewater treatment, in particular to a treatment method and system for CIT sulfuric acid wastewater containing heavy metals. Background technique [0002] The sulfuric acid wastewater containing arsenic, lead, fluorine and other pollutants discharged from the iron flow mine acid production process is a kind of highly toxic sulfuric acid wastewater. The traditional sulfuric acid wastewater treatment method is to use lime slurry, ferrous sulfate and compressed air to neutralize and aerate the sulfuric acid wastewater in a reaction tank, so that the arsenic, lead, fluorine and other pollutants in it form sediments, and then let the wastewater enter the Sedimentation in the sedimentation tank; generally through such two-stage "reaction-sedimentation" treatment, the effluent is discharged after adjusting the pH value with sulfuric acid. This method is more effective for removing pollutants such as arsenic, ...

AI Technical Summary

Problems solved by technology

This method is more effective for the removal of pollutants such as arsenic, lead, and fluorine in sulfuric acid wastewater, but there is also the problem of clogging of the reaction pool, which restricts its operation stability.

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