Screening the optimal modified biochar for nitrogen retention in black soil

Area of Science:

• Environmental Science
• Soil Science
• Materials Science

Background:

• Nitrogen loss and pollution pose significant environmental challenges.
• Biochar addition to soil is a promising strategy for nitrogen interception due to its unique properties.

Purpose of the Study:

• To screen optimal modified biochar for nitrogen adsorption.
• To investigate the effects of biochar application methods on soil properties and nitrogen retention.

Main Methods:

• Acid-base modification and batch adsorption tests were used to screen biochar.
• Soil column leaching tests evaluated the impact of biochar on soil physicochemical properties and nitrogen adsorption.

Main Results:

• Biochar pyrolyzed at 700°C and modified with 0.1 mol/L HCl exhibited the highest nitrate nitrogen adsorption capacity (121.46 mg/g).
• Nitrogen adsorption followed the Langmuir model, indicating homogeneous monolayer adsorption.
• Mixing modified biochar with black soil increased pH, ammonia nitrogen, and nitrate content.

Conclusions:

• Optimized biochar, produced at 700°C and modified with HCl, effectively adsorbs nitrogen.
• Biochar application improves soil physicochemical properties and enhances nitrogen retention in black soil.
• This study provides a basis for the optimal use of biochar in soil management for environmental remediation.