Removal of aniline substances

How does resin "capture" aniline?

The removal of aniline substances by resin mainly relies on the following forces:

Pore size sieving effect: There are specific-sized channels inside the resin. Only when the size of aniline molecules matches the channels can they enter the interior and be adsorbed.

Hydrophobic effect: Resin skeletons are usually hydrophobic, and the benzene ring of aniline is also a hydrophobic structure. There will be a strong hydrophobic interaction between the two.

π-π stacking: When the resin skeleton contains aromatic structures such as benzene rings, face-to-face or edge-to-face π-π stacking will form between the benzene rings of the resin and those of the aniline. This is a very powerful intermolecular force.

Electrostatic effect: Under specific pH conditions, aniline molecules or functional groups of resins may become charged, generating electrostatic attraction.

Technical advantages:

High selectivity: By adjusting the pore structure and specific surface area of the resin, high selectivity adsorption of specific aniline substances can be achieved.

High-efficiency removal: It still maintains a high removal rate for low-concentration aniline wastewater, reducing the effluent concentration to below 0.5mg/L.

Renewability: Resin that has reached adsorption saturation can be regenerated with appropriate desorption agents (such as acids, bases or organic solvents) and reused hundreds of times, significantly reducing operating costs.

Resource recycling: The aniline substances desorbed can be recycled and reused, turning waste into treasure, which is in line with the concept of circular economy.

Environmentally friendly: It does not cause secondary pollution and avoids the more toxic by-products that may be produced by chemical oxidation methods.

Regeneration:

When the resin reaches adsorption saturation, desorption regeneration is carried out:

Backwash with clean water to remove impurities

Aniline is desorbed by passing a desorbent (such as methanol, dilute acid or dilute alkali) through a resin bed

Rinse with clean water and the resin regeneration is complete

For high-concentration aniline wastewater (>1000mg/L), most of the aniline can be first recovered through resin adsorption, and then advanced treatment can be carried out in combination with biological treatment and other processes.