The removal of contaminants in co-solute systems is a pressing issue. Herein, the adsorption capacities of magnetic biochars and activated carbon were investigated and compared for various aqueous anions, including As(V), tetracycline (TC) and NO₃⁻, existed alone or as a mixture. One-step (pre-treating biomass with FeCl₃ before pyrolysis (FB)) and two-step (pyrolysing biomass before modification with FeCl₃ (BF)) magnetization methods were applied to synthesize magnetic biochars. Magnetic activated carbon (AF) was also prepared with the two-step magnetization method. FB presented the highest adsorption capacities for As(V) and NO₃⁻ respectively at 6.77 and 6.31 mg g⁻¹. AC (612.38 mg g⁻¹) showed the highest adsorption capacity for TC, which decreased by 189.76% after magnetization. Magnetization was proved to be a promising method to improve the adsorption of both As(V) and NO₃⁻ on adsorbents through enhanced electrostatic attraction, while the adsorption of TC depended mainly on high specific surface area of the adsorbent. Results from competitive adsorption in the co-solute systems suggested that FB had a great potential for application in the co-contaminated environment (heavy metal and inorganic anions), and AF could be a promising adsorbent to remediate multiple-contaminated environment (i.e. organic pollution and heavy metal/inorganic anions).

在共溶体系中去除污染物是一个紧迫的问题。在此，磁性生物炭和活性炭的吸附能力进行了研究，并用于各种含水阴离子，包括随着（V），四环素（TC）和NO相比₃ ^- ，存在单独使用或作为混合物使用。采用一步法（热解（FB）前用FeCl ₃预处理生物质）和两步法（FeCl ₃改性（BF）前将生物质热解）磁化法合成磁性生物炭。还通过两步磁化方法制备了磁性活性炭（AF）。FB呈现最高吸附容量为的As（V）和NO ₃ ^-分别在6.77和6.31毫克克^-1。AC（612.38 mg g ^-1）对TC表现出最高的吸附能力，在磁化后下降了189.76％。磁化被证明是改善两者的As（V）和NO的吸附有希望的方法₃ ^-上通过增强静电引力的吸附剂，而TC的吸附主要取决于吸附剂的高比表面积。共溶体系中竞争性吸附的结果表明，FB在共污染环境（重金属和无机阴离子）中具有巨大的应用潜力，AF可能是有望修复多污染环境（即有机污染）的吸附剂和重金属/无机阴离子）。