Dual-Anode electrochemical strategy enabling struvite-based nutrient recovery coupled with antibiotic degradation

• A dual-anode system was developed for nutrient recovery and antibiotics degradation • The system integrates a BDD anode and a Mg sacrificial anode in single reactor • 98% phosphorus recovery and 58.8% sulfadiazine degradation were achieved • Sequential operation improved antibiotics removal to 77.6% and P recovery to 100% • Increasing BDD current improved antibiotic removal without affecting Mg dissolution Livestock wastewater typically contains high concentrations of nutrients and antibiotics that are difficult to remove, posing serious environmental risks. This study proposed a dual-anode electrochemical system (DA-EMSP), which simultaneously integrates a boron-doped diamond (BDD) anode for sulfadiazine (SD) degradation and a sacrificial magnesium (Mg) anode for struvite precipitation. The DA-EMSP system achieved 58.8% SD degradation and 98% phosphorus (P) recovery within 72 min of operation. However, the in-situ formation of struvite was found to hinder SD degradation efficiency, likely due to the adsorption and physical shielding of SD by the struvite precipitates. To address this, a multi-stage operation strategy was developed to conduct oxidation and precipitation sequentially. The results revealed that sequential oxidation followed by precipitation (Seq-O/P) achieved the highest SD degradation efficiency (77.6%) while maintaining complete P recovery (100%). Further analysis showed that increasing the BDD current significantly improved SD degradation (up to 93%) without significantly impacting bulk pH or Mg²⁺ release. With flexible circuit control and dual-functionality, the DA-EMSP system demonstrates strong potential as a post-treatment strategy for livestock wastewater containing both antibiotics and nutrient pollutants.