The scenario created by the test questions is the process flow chart of phenol recovery and treatment in industrial wastewater, which involves five kinds of equipment, four kinds of chemical raw materials and a variety of organic and inorganic chemical reactions. This is a typical organic-inorganic comprehensive problem.

From the flow chart of phenol-containing industrial wastewater treatment, the following analysis can be made:

(1) Industrial wastewater and benzene enter into equipment I to obtain phenol, benzene solution and phenol-free industrial wastewater (which can be discharged), indicating that the extraction is carried out in equipment I, and phenol is extracted from industrial wastewater by using the similar structure of benzene and phenol, and the lower industrial wastewater is discharged separately, and the upper phenol-benzene solution enters equipment II.

(2) sodium hydroxide solution is injected into the equipment II filled with phenol-benzene solution. At this time, acidic phenol reacts with sodium hydroxide to generate sodium phenolate and water.

Sodium phenolate is an ionic compound which is easily soluble in water. With the occurrence of the above chemical reaction, the liquid in device II is divided into two layers, the upper layer is benzene layer, and the lower layer is sodium phenolate solution (that is, the substance A in question). The benzene in the upper layer is sent back to equipment I through pipelines to continue extracting phenol from industrial wastewater for recycling, and the solution of sodium phenolate (A) in the lower layer enters equipment (III).

(3) Excess carbon dioxide gas is introduced into the equipment III filled with sodium phenolate solution, and the two substances react chemically to generate phenol and sodium bicarbonate. The essence of this chemistry is the metathesis reaction between weak acid salt and "strong" acid (which is more acidic than phenol), and the chemical equation is as follows:

The precipitated phenol contains a small amount of water, which is an oily liquid and sinks in the lower layer of equipment III liquid. After liquid separation, phenol can be obtained by rectification. The upper liquid b is a solution, which is transported to the equipment Ⅳ through the pipeline.

(4) Add quicklime () to the equipment IV containing sodium bicarbonate solution, and the quicklime will combine with the water in the sodium bicarbonate solution to mature lime, and the hydrated lime will react with it to generate precipitate. The chemical equation is as follows:

If the above two reactions are combined and written as the following formula:

Equally correct. The solution and precipitate are separated by filtration.

The solution obtained from the reaction enters the equipment II through a pipeline for recycling; The obtained precipitate enters the equipment ⅴ.

(5) The raw material in equipment V is solid, and the products obtained are calcium oxide and carbon dioxide. Therefore, the equipment ⅴ should be essentially a lime kiln, in which the following chemical reactions take place:

The carbon dioxide obtained from the reaction enters the equipment III, and the calcium oxide obtained from the reaction enters the equipment IV.

To sum up, benzene, calcium oxide, sodium hydroxide and carbon dioxide can be recycled in the process of extracting phenol from industrial wastewater containing phenol, and there should be no consumption in theory.