Acidic wastewater treatment system and technological method

Abstract

The invention discloses an acidic wastewater treatment system and an acidic wastewater treatment technological method. The acidity is reduced by adding a natural mineral material, the pH is adjusted by adding alkali, and aluminum ions are produced into aluminum hydroxide; while the acidity is reduced, calcium in the natural mineral material is converted into calcium ions and the calcium ions reactwith sulfuric acid or phosphoric acid in waste acid to produce calcium sulfate or calcium phosphate; the aluminum hydroxide, the calcium sulfate and the calcium phosphate are recycled; the acidic wastewater treatment system occupies a small floor area, has a large treatment amount and saves the civil engineering cost and the equipment investment cost; by the acidic wastewater treatment technological method, the amount of produced sludge is small, and huge waste as well as formation of a large amount of waste slag, which are caused by underutilization of lime are avoided; by the acidic wastewater treatment technological method, the aluminum hydroxide, the calcium sulfate and the calcium phosphate can be recycled, resource disposal of wastewater is achieved, formation of secondary pollutionis avoided, and the environment-friendly effect is outstanding.

Description

technical field [0001] The invention relates to the technical field of wastewater treatment, in particular to an acid wastewater treatment system and a treatment process method thereof. Background technique [0002] The wastewater produced by cleaning the surface of aluminum foil contains a large amount of mixed acid and aluminum ions (free acid content is 0.5-17%, aluminum ion content is 2-8%), and the traditional treatment method is acid-base neutralization. Method 1: Add a large amount of liquid caustic soda or caustic soda, adjust the acidic wastewater to neutral, and convert aluminum ions into aluminum hydroxide. After sedimentation, the sludge is sent to the filter press room for dehydration treatment, and the supernatant is discharged up to the standard; Method 2: Throwing Add a large amount of quicklime powder or slaked lime for neutralization. [0003] The above two methods are neutralized by acidic wastewater and alkaline substances, through chemical reaction and ...

AI Technical Summary

Problems solved by technology

The market price of lime is 500-900 yuan / ton, the price of 20% liquid caustic soda is 450-800 yuan / ton, and the price of caustic soda is 3000-4200 yuan / ton, which leads to the high cost of wastewater treatment, and the operating cost is about several Tens to several million, which is unbearable for ordinary enterprises;

[0006] 2) Powder particles cause dust

Poor feeding equipment or manual feeding lead to severe fly ash and poor environment. Generally, it is necessary to add a silo and an automatic feeding system to improve the environment accordingly, but it greatly increases the investment cost and processing cost.

[0007] 3) Lime utilization rate is very low

The solubility of lime is very low, its solubility is less than 0.16g under normal temperature conditions, and the solubility decreases with the increase of temperature, and calcium ions are difficult to ionize, the stirring effect of lime slurry is poor, and the utilization rate of lime is very low, resulting in a lot of waste (utilization rate Generally 40%-70%)

[0008] 4) Large amount of slag

[0009] 5) The waste slag forms secondary pollution, which increases the treatment cost

The waste residue must be processed by a qualified professional unit, and the current processing fee is 1000-3500 yuan / ton

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