Extraction of phenol from wastewater
Method 1: 1. Wastewater + benzene = benzene, phenol + wastewater — Filtration —
2. Phenol, benzene + Na OH = benzene + sodium phenolate—filtration—
3. Sodium phenolate + carbon dioxide = phenol + sodium bicarbonate —liquid separation—
4. Sodium bicarbonate + calcium oxide = calcium carbonate + NaOH calcium carbonate = calcium oxide + carbon dioxide
Raw materials can be recycled
Method 2: 1. Wastewater + benzene = benzene, phenol + wastewater — Filtration —
2. Phenol, benzene + sodium carbonate = benzene + sodium phenolate + sodium bicarbonate —filtration—
3. Sodium phenolate + carbon dioxide = phenol + sodium bicarbonate —liquid separation—
4. Sodium bicarbonate = sodium carbonate + carbon dioxide + water
Raw materials can be recycled
Method 2 should be okay, but if it is to be recycled, the phenol content should not be much, so the reagents that can be used will not be large!
In addition, there is a question about whether sodium carbonate can react quickly with phenol in the second step of the second middle school, and whether the reaction can be complete, because this reaction seems to be a two-phase reaction! So it makes sense to use sodium hydroxide in method one!
Separation method of mixture of phenol and benzene
(1) Add sodium hydroxide solution, shake and separate. The upper layer is benzene.
(2) Remove the lower layer solution and pass in excess carbon dioxide to separate the liquids. The lower layer is phenol.
Note: Bromine water cannot be used. Tribromophenol generated by the reaction of phenol and bromine water is soluble in benzene, so bromine water cannot be added.