A method and system for biologically treating acid mine wastewater while recovering iron ions

Abstract

The invention provides a method and system for biologically treating acidic mine wastewater while recovering iron ions. The method comprises: (1) Biomineralizing the acidic mine wastewater by acidophilic iron-oxidizing bacteria, then performing circular biological reduction treatment by acidophilic iron-reducing bacteria, and then entering an alkali adjustment tank to circulate and adjust pH, and then the effluent is circulated to biomineralization treatment (2) After a period of reaction, the waste water is drawn out from the end of the sump, which can be connected to the lime neutralization treatment system, and jarosite minerals or Shi's minerals can be recovered in the biomineralization unit. The bacteria screened by the invention are indigenous strains existing in the actual mine environment, and can be fully applied to the treatment of mine wastewater. The invention adopts circulation treatment to increase the precipitation amount of iron in the acid waste water, and is subsequently connected with lime neutralization treatment, so that the mine waste water can fully meet the standard.

Description

technical field [0001] The invention belongs to the field of waste water treatment, and relates to a method and a system for biologically treating acidic mine waste water and simultaneously recovering iron ions. Background technique [0002] Acid mine drainage (AMD) is a challenging environmental issue currently facing the global mining industry. It is a type of drainage with low pH and high iron ions produced after biological and chemical reactions occur in the mining or waste slag accumulation process of mines. Extremely acidic (pH: 2.0-3.5), rich in sulfate (SO 4 2- : 2000-6000mg / L), high iron content (Fe 2+ or Fe 3+ : 500-4500mg / L), toxic metals (As, Cd, Cu, Pb, Ni, etc.) are typical characteristics of AMD. The direct discharge of AMD seriously threatens the safety of the water and soil environment and the ecosystem around the mining area, causing huge losses to people's production and life. [0003] The neutralization precipitation method is a relatively mature me...

AI Technical Summary

Problems solved by technology

But this method still has many problems in use: (1) a large amount of iron ions and sulfuric acid that exist in AMD are easy to form precipitation to wrap on lime surface in neutralization process, reduce neutralization efficiency, thereby cause the raising of alkali neutralization reagent dosage (2) a large amount of iron and sulfate ion directly precipitate in AMD, are difficult to recycle, cause the waste of resource; Difficulty in safe disposal of mud

This method uses acidophilic Thiobacillus ferrooxidans, which can realize the mineralization process under in-situ conditions, but the disadvantages are that the efficiency of biomineralization treatment is low, and the microorganisms are directly applied to wastewater treatment, and there is a problem that microorganisms are easy to lose problems, it is difficult to fully apply to the actual mine wastewater treatment process

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