1. Activation treatment:

○ Physical activation: high temperature activation (such as pyrolysis), ultrasonic activation, etc. to enhance adsorption performance.

○ Chemical activation: Use acid (such as sulfuric acid, nitric acid), alkali (such as NaOH) or oxidant (such as H₂O₂) to improve the solubility and functional group activity of humic acid.

○ Bioactivation: Microbial fermentation treatment to improve its biodegradability and fertilizer efficiency.

○ Note: The activation method should be selected according to the target application field, and the reaction conditions (temperature, pH, time) should be strictly controlled to avoid excessive modification and structural damage.

2. Compounding and modifier addition (optional):

○ Add other ingredients (such as trace elements, nitrogen, phosphorus and potassium fertilizers, surfactants) as needed and mix them evenly to prepare composite humic acid products.

○ Completed by double screw mixer or high speed blender.