How sorbents work
Sorbent compounds are divided by the principle of action into ionics, absorbents and adsorbents. Absorbents absorb other substances with their entire mass - they mix with them and form a solution. Adsorbents collect the substance on their surface without mixing with it.
Activated carbon is an adsorbent that is used to improve the odor of drinking water and reduce its oxidation
Adsorbents are divided into hydrophilic and hydrophobic. Hydrophilic absorbs water, hydrophobic does not, so they are used to collect contaminants in water: oil, oil, grease. Hydrophilic sorbents are used to remove excess moisture from the air.
Silica gel refers to hydrophilic sorbents. Manufacturers of goods put it in the package so that the air inside is not humid
Unlike absorbents and adsorbents, ion exchangers work on a different principle. To bind a substance, they exchange ions with it. According to the type of charge, ion-exchangers are divided into cation-exchangers and anion-exchangers. Anion-exchangers exchange negatively charged particles, cation-exchangers exchange positively charged particles.
Types of sorbents
Sorbent materials are classified by origin and aggregate state.
According to the aggregate state
There are liquid and solid sorbent materials. Solid materials are divided into granular and fibrous. Granular includes not only granules, but also a powder.
Fibrous sorbents look like absorbent cotton, but consist of synthetic polymer fibers. They are used to make filtering elements for water and air purification, booms and oil-absorbing mats for oil spill elimination, used in respirators, gas masks and other PPE.
By origin
Sorbent materials can be synthetic or natural. For example, activated carbon is a natural material from charcoal. Silicon dioxide is a sorbent of synthetic origin - it is obtained by heating silicon to 500 °C.