Adsorbent & Ion Exchange Resins for Organic Wastewater Treatment

Organic wastewater refers to wastewater containing organic substances, commonly originating from industrial production, agricultural activities, and domestic sewage. Due to the complex composition of organic wastewater, it poses severe pollution risks to water bodies and the environment, making its treatment particularly crucial. Resins, as efficient wastewater treatment materials, play a significant role in organic wastewater treatment due to their excellent adsorption properties and ion exchange & regeneration capabilities.

In organic wastewater treatment, the adsorption and ion exchange resins are adopted to remove heavy metal ions, organic pollutants and recover valuable substances.

• Ion Exchange Resins: These resins remove ionic pollutants from water through ion exchange mechanisms. Common types include cation and anion exchange resins, which are suitable for water treatment and heavy metal removal.
• Adsorption Resins: These include polystyrene and polymer resins, primarily used for removing organic pollutants from water. These resins utilize physical adsorption or chemical adsorption to eliminate contaminants.

For better performance, we provide the LWT Series, which is specially designed for organic wastewater treatment.

• LWT Series, resins specially designed for organic wastewater treatment

The ion exchange resins or adsorption resins are used for heavy metal removal, organic pollution removal and valuable substances recovery. They performs well due to their excellent ion exchange capacity and adsorption resins.

Heavy Metal Removal

It adopts ion exchange resins, which can effectively remove heavy metal ions (e.g., lead, cadmium, copper) from wastewater through ion exchange mechanisms. These resins have negatively charged surfaces that attract positively charged metal ions.

For cation exchange resins, when wastewater containing lead ions (Pb²⁺) contacts the resin, the sodium ions (Na⁺) on the resin exchange with lead ions:

R-Na⁺ + Pb²⁺ → R-Pb²⁺ + Na⁺

In that,

• R-Na⁺: Active group on the resin with sodium ions (R represents the organic part of the resin)
• Pb²⁺: Lead ions in wastewater, carrying a +2 charge
• R-Pb²⁺: State of the resin after binding with lead ions
• Na⁺: Sodium ions released back into the wastewater

Lead ions are effectively removed, improving water quality.

Removal of Organic Pollutants

It adopts adsorption resins, which can remove organic pollutants such as benzene and ketones from water through physical or chemical adsorption. Their high surface area and specific pore structures enable effective capture of organic molecules.

For polystyrene adsorption resins, when organic pollutants (like benzene) contact the resin, benzene molecules adsorb onto the resin surface via van der Waals forces:

C₆H₆ (aq) + R ⇌ C₆H₆ (adsorbed) + R

In that,

• C₆H₆ (aq): Benzene molecules in the aqueous phase
• R: Organic part of the resin
• C₆H₆ (adsorbed): Benzene molecules adsorbed on the resin surface

The concentration of benzene in the water decreases, achieving the removal of organic pollutants.

Recovery of Valuable Substances

It adopts resins, which possess selective adsorption capabilities for specific metal ions, making them suitable for recovering valuable metals such as gold and silver from wastewater. By controlling pH and other operational conditions, selectivity for specific metals can be enhanced.

In the recovery of gold (Au), commonly used resins contain amine or thiol groups. When gold ions contact the resin, they form a coordination compound:

Au³⁺ + R-SH → R-S-Au + 2H⁺

In that,

• Au³⁺: Gold ions in wastewater, carrying a +3 charge.
• R-SH: Thiol group on the resin (R represents the organic part of the resin).
• R-S-Au: State of the resin after binding with gold ions, forming a complex.
• 2H⁺: Hydrogen ions released during the reaction.

Gold ions are effectively adsorbed and transformed into a recoverable form, reducing resource waste.

Industry

• Chemical Industry: Removing solvents and chemical raw materials generated during production.
• Pharmaceutical Industry: Treating wastewater generated during drug manufacturing.
• Food Processing Industry: Removing organic matter and nutrients generated during food processing.
• Textile Industry: Removing dyes and auxiliary agents from wastewater.

Specific Applications

• Phenol, p-cresol, o-cresol, m-cresol, p-nitrophenol, n-nitrophenol, p-aminophenol, acetaminophen
• Benzyl alcohol, Phenylethyl alcohol
• Chlorobenzoic acid, Benzoic acid, Salicylic acid, 2,4-dichlorophenoxyacetic acid (2,4-D acid), Pyridine
• 2-Naphthol, Aniline, p-Toluidine, o-Chloroaniline, 2,3-dihydroxybenzoic acid, Benzoquinone
• Dichloroethane, Dichloromethane, Cyclohexane, Tetrahydrofuran, Butanol, Octanol
• Benzene, Toluene, Chlorobenzene, Benzyl chloride, Chlorophenol