How to handle phosphate ions in strong acids
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How to deal with phosphate ions in 50% strong acid?
The acid should first be recovered and treated to increase the pH. Finally, the phosphate ions are chemically precipitated. In other words, a processing order is needed.
By removing phosphate, the strong acid can also be recovered; since the strong acid is recovered and processed first, there is no need to remove phosphate separately. Currently, it is not easy to remove phosphate from strong acids, and it might not be worth the effort. May I ask what type of acid the original poster is referring to as a 50% strong acid? It’s tricky with sulfuric acid
Patent: A method for treating wastewater containing phosphate ions, which enables a high efficiency in removing phosphate ions to be maintained over the long term. This wastewater treatment method uses electrodes containing iron and/or aluminum to electrochemically precipitate iron ions and/or aluminum ions in wastewater containing phosphate ions, thereby causing the phosphate ions to aggregate and precipitate as water-insoluble salts of iron and/or aluminum. The current is controlled so that the molar ratio of the precipitated metal to the phosphorus concentration in the wastewater flowing into the electrolytic cell installed in the wastewater treatment device becomes 1–4.
Inorganic acids can be separated using organic complexation extraction methods.
What we need is 48% hydrobromic acid; what more do we need if it’s neutralized? In this acid, phosphate is an impurity ion!
It seems that electrolysis is the only method effective for removing phosphates in strong acid environments, but the treatment cost is relatively high.
In a strong acid medium, it is not feasible to remove only the phosphate ions by precipitation or neutralization; since the impurity to be removed requires the presence of the strong acid medium, this approach is not viable. There are various methods that can be used; LZ might as well look up information following this approach ； First, the method of organic complexation extraction and separation can be used, or distillation separation based on different boiling points can be employed directly. Second, ion exchange can be carried out using ion exchange resins. Third, ion membrane exchange could be considered as an option.