Choosing the right activated carbon depends on your specific application. Let me outline the key points to help you quickly find the right one.

1. Define your application first.

Drinking water purification: Choose coconut shell activated carbon with a high iodine value (800-1200mg/g) and low ash content (≤5%) for safety and high efficiency.

Industrial wastewater treatment: Requires washable, highly adsorbent columnar activated carbon suitable for long-term use.

Food and beverage processing: Must meet food-grade standards, such as FDA-certified coconut shell activated carbon, to ensure no secondary pollution.

Air purification: Choose coconut shell activated carbon with a large specific surface area and good pore structure for more effective adsorption of formaldehyde, benzene, etc.

2. Consider key parameters.

Iodine value: 800-1200mg/g is recommended for drinking water treatment; slightly lower is acceptable for air purification.

Ash content: The lower the better. For drinking water, ≤5% ash content is recommended; for industrial wastewater, this can be relaxed to ≤6%. 

3. **Compressive Strength:** Columnar activated carbon is recommended to have a strength ≥0.8 MPa, and granular activated carbon ≥0.85 MPa to prevent breakage during use.

4. **Select the Right Physical Form:**

Granular activated carbon: Suitable for continuous flow treatment, such as filters and filtration systems.

Powdered activated carbon: Used for emergency treatment or special pollutants; it adsorbs quickly but requires solid-liquid separation.

Columnar activated carbon: Commonly used in industrial wastewater treatment; it is washable and has high strength.

5. **Water Quality Compatibility:**

pH value: Choose alkaline activated carbon for acidic water and acidic activated carbon for alkaline water.

**Pollutant Type:** For small molecule organic matter (such as residual chlorine), check the iodine value; for large molecules (such as COD), check the carbon tetrachloride value.