Structure for treating saline alkali soil and biological treatment method

A biological treatment method for treating saline alkali soil comprising the following steps:

• piling a cleaned plough layer (1) to one side, then paving a collecting layer (3) and impermeable layers (2) in sequence, and paving a collecting pipe network and collection pools (7) in the meantime;
• the impermeable layers (2) being prepared by mixing biochar powder, sodium bentonite, calcium bentonite, coal ash, and saline alkali soil and adding water for humidifying till the water content is 25-35%, and paving the above uniformly mixed components in layers and grinding the same, wherein the paving thickness of the first layer is 80-100 mm, and then the thickness of each layer is 40-50 mm with the totaling 2-3 layers;
• incorporating straw particles, straw biochar particles, zeolite, and diatomaceous earth into the plough layer (1) and restoring the plough layer to an original position;
• when the impermeable layers (2) are subjected to leakage after the collecting layer (3) operates 5 years or more, taking out the collecting layer (3) and placing the collecting layer in clean water to be soaked for 12-24 hours, cleaning the collecting layer (3), and airing the solution and cleaning solution after soaking, evaporating and concentrating salt crystals, and collecting the salt crystals;
• collecting the liquid in the collection pool (7) every 2 months from March to October;
• and filtering the collected liquid first, and then evaporating, concentrating, and crystallizing the liquid.