Phosphorus Removal from Dirty Farmyard Water by Activated Anaerobic-Digestion-Derived Biochar

Area of Science:

• Environmental Science
• Materials Science
• Chemical Engineering

Background:

• Effective management of anaerobic digestate is crucial for waste valorization and anaerobic digestion sustainability.
• Phosphorus removal from wastewater is a significant environmental challenge in agriculture and industry.

Purpose of the Study:

• To investigate the use of biochar derived from anaerobic digestate for phosphorus removal from dirty irrigation water.
• To optimize biochar properties through steam and KOH activation for enhanced phosphorus adsorption.
• To analyze the adsorption kinetics and thermodynamics of phosphorus removal by the optimized biochar.

Main Methods:

• Biochar production from anaerobic digestate.
• Optimization of biochar textural properties via steam and KOH activation.
• Batch adsorption experiments to evaluate phosphorus removal efficiency.
• Analysis of adsorption kinetics and thermodynamic parameters.

Main Results:

• Optimized biochar (AD-N2) exhibited a remarkable phosphorus adsorption capacity of 8.99 mg g⁻¹.
• Phosphorus adsorption followed the Elovich equation, indicating a complex adsorption mechanism (R² = 0.95).
• The adsorption process was found to be endothermic (ΔH⁰ = 17.93 kJ mol⁻¹) and spontaneous (ΔS = 96.24 J mol⁻¹ K⁻¹).

Conclusions:

• Activated biochar derived from anaerobic digestate is a promising adsorbent for phosphorus removal from contaminated water.
• The study provides insights into the adsorption mechanism and thermodynamic favorability of phosphorus removal.
• This approach offers a sustainable solution for managing phosphorus pollution in industrial and agricultural settings.