Atypical temperature-dependent ammonium adsorption on co-pyrolyzed biochars: Low-temperature enhancement via cation exchange

Key Points

• Ammonium adsorption is enhanced at lower temperatures, which is atypical compared to conventional expectations.
• The study shows a significant change in ammonium retention, quantified as a 50% increase at 10°C compared to higher temperatures.
• Analysis of co-pyrolyzed biochars revealed mechanisms of cation exchange that contribute to the observed temperature dependence.
• Findings indicate that biochars can be optimized for nutrient management in agricultural settings under varying temperatures.