Treatment of phosphoric acid-containing wastewater
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I have a material; after rinsing it, the wastewater contains low concentrations of phosphoric acid. If this wastewater is discharged directly, it certainly won’t pass environmental regulations, right? Is there any way to deal with it? Is it okay to add Ca(OH)2? Baidu showed the following response: If everything turns into a precipitate, it’s easy to solve the problem; but if soluble salts are formed, that becomes troublesome a) Add H3PO4 drop by drop to the clarified lime water, shaking while adding. Phenomenon: White precipitate begins to form, and then gradually dissolves. Reaction equations:3Ca(OH)2 + 2H3PO4 = Ca3(PO4)2↓ + 6H2O
Ca3(PO4)2 + H3PO4 = 3CaHPO4
CaHPO4 + H3PO4 = Ca(H2PO4)2
b) Add clear lime water drop by drop to the phosphoric acid solution, stirring continuously as it is added. Phenomenon: Initially, no phenomenon occurs; when a certain amount of lime water is added, a white precipitate forms. Reaction equations:
Ca(OH)2 + 2H3PO4 = Ca(H2PO4)2 + 2H2O
Ca(H2PO4)2 + Ca(OH)2 = 2CaHPO4↓
2CaHPO4 + Ca(OH)2 = Ca3(PO4)2 + 2H2O
There’s a lot of information online regarding PH and the dosage of chemicals, but their actual effects are unknown
How can phosphogypsum be used to produce sulfuric acid conveniently? Can wastewater containing phosphoric acid also be processed to produce sulfur?
1# hby1224 can be precipitated by neutralization with calcium hydroxide to form calcium hydrogen phosphate dihydrate. For specific details, refer to the calcium hydrogen phosphate production process.
A chemical-physical-biological treatment method should be adopted
What are the specific measures? It cannot be determined qualitatively; data is needed. Those in technical fields don’t need formal language.
Okay, I’m also looking for the same thing, but I can’t find it; it’s really frustrating.
Add lime water to adjust the pH to neutral, then allow sedimentation; filter the thick slurry and recycle the water