This study addresses the challenges of water pollution and solid waste treatment by presenting a two-step wet ball mill pyrolysis method for synthesizing magnetic biochar (MBC) from Water Hyacinth (Eichhornia crassipes) and basic oxygen furnace slag (BOFs) for adsorbing phosphate in water. The MBC showed excellent magnetic properties, with a coercivity of 259.3 Oe and a remanence of 0.552 emu˖g⁻¹, and a high specific surface area (∼57.9 m²˖g⁻¹) and micropore volume (0.070 m³˖g⁻¹). The MBC had a rough surface and compact regular pore structure with a distribution of Fe³O⁴ and FeO. It exhibited a high phosphate adsorption capacity, reaching a maximum adsorption capacity of 39 mg˖g⁻¹, and the adsorption process followed the pseudo-second-order kinetic model. The main adsorption mechanism was found to be chemical adsorption. The experiment investigated the loading efficiency of iron from BOFs and the mechanism of phosphate adsorption. This approach is cost-effective, environmentally friendly, and efficient, achieving the concept of “waste treating waste."

本研究提出了一种两步湿法球磨机热解法，用于从水葫芦（凤眼莲）和碱性氧气炉渣（BOF ）中合成磁性生物炭（MBC ）以吸附水中的磷酸盐，从而解决水污染和固体废物处理的挑战. MBC 表现出优异的磁性能，矫顽力为 259.3 Oe，剩磁为 0.552 emu˖g ⁻¹，具有高比表面积（~57.9 m ² ˖g ⁻¹ ）和微孔体积（0.070 m ³ ˖g ^{− 1} ). MBC具有粗糙的表面和致密的规则孔结构，分布有Fe ³ O ⁴和氧化铁。它表现出很高的磷酸盐吸附容量，最大吸附容量达到39mg˖g ^-1 ，吸附过程遵循准二级动力学模型。发现主要的吸附机理是化学吸附。该实验研究了 BOF 的铁负载效率和磷酸盐吸附机理。这种方法具有成本效益、环境友好和高效，实现了“废物处理废物”的概念。