Excessive phosphorus (P) in marine and freshwater systems has been identified as a primary perpetrator for the harmful and nuisance algal blooms. In this study, a novel designer biochar was produced from sawdust biomass treated with lime sludge prior to pyrolysis. The adsorption of dissolved P on the designer biochar was comprehensively evaluated under different experimental conditions. It revealed that the removal of dissolved P by the designer biochar was more efficient than unmodified biochar, lime sludge, and their post-combination, suggesting that the pretreatment of biomass with lime sludge for the designer biochar production has a significantly synergic effect on enhancing P removal. Post-adsorption characterization and mathematical modeling analyses indicated that the adsorption of dissolved P on the designer biochar could be controlled by multiple mechanisms including physical and chemical adsorption. The precipitation reaction between P anions and metal ions on the surface of the designer biochar was identified as a predominant mechanism. The X-ray diffraction showed that the precipitation reaction generated a series of P fertilizer forms depositing onto the designer biochar. In addition, batch adsorption experiments showed that both initial solution pH and coexisting anions had a lesser effect on the P removal by the designer biochar. This study proposed that the designer biochar could be a promising sorbent to remove dissolved P, and the nutrient-captured biochar could be used as a fertilizer to recover nutrients.

海洋和淡水系统中过量的磷 (P) 已被确定为有害和令人讨厌的藻类大量繁殖的主要肇事者。在这项研究中，一种新颖的设计生物炭是由在热解之前用石灰污泥处理的锯末生物质生产的。在不同的实验条件下，综合评价了设计生物炭对溶解磷的吸附。结果表明，设计生物炭对溶解的磷的去除比未改性的生物炭、石灰污泥及其后组合更有效，表明生物质与石灰污泥预处理用于设计生物炭生产对提高磷具有显着的协同作用。移动。吸附后表征和数学模型分析表明，溶解磷在设计生物炭上的吸附可以通过物理和化学吸附等多种机制来控制。P 阴离子和金属离子在设计生物炭表面上的沉淀反应被确定为主要机制。X 射线衍射表明，沉淀反应产生了一系列磷肥形式，沉积在设计生物炭上。此外，批量吸附实验表明，初始溶液 pH 值和共存阴离子对设计生物炭的 P 去除影响较小。这项研究提出，设计生物炭可能是一种有前途的吸附剂，可以去除溶解的磷，而捕获养分的生物炭可以用作肥料来回收养分。