In this study, hierarchical birnessite-type MnO₂/biochar composites (δ-MnO₂/BCs) were synthesized by a hydrothermal technique, and their Cu(II) removal performance was examined in aqueous solution. Morphological characterization confirmed that a three-dimensional flower-like structure of δ-MnO₂ was formed, which results in effective adsorption affinity towards Cu(II). The effects of solution pH, adsorbent dosage, and ionic strength on the adsorption behavior of the prepared materials were systemically investigated. The adsorption kinetics indicated that Cu(II) adsorption onto δ-MnO₂/BCs follows a pseudo-second-order model. Analysis of possible adsorption/diffusion mechanisms suggested that the adsorption process is controlled by both film and pore diffusion. The adsorption isotherms fit closely to the Sips isotherm model, and the theoretical maximum adsorption capacities of Cu(II) on the synthesized δ-MnO₂/BCs are approximately 124, 154, 199, and 230 mg/g at 15, 25, 35, and 45 °C, respectively. Adsorption-desorption studies demonstrated the recyclability of the δ-MnO₂/BCs for the removal of Cu(II) from aqueous solutions.

在这项研究中，层次化水钠锰矿型的MnO ₂ /生物炭复合材料（δ-的MnO ₂ / BCS）中通过水热技术合成，和在水溶液中进行了检查他们的铜（II）的去除性能。形态学特征证实三维花状δ-的MnO结构₂被形成，其结果在有效的吸附亲合性对铜（II）。系统研究了溶液的pH值，吸附剂用量和离子强度对制备材料吸附性能的影响。吸附动力学表明，铜（II）吸附到δ-的MnO ₂/ BCs遵循伪二阶模型。对可能的吸附/扩散机理的分析表明，吸附过程受薄膜和孔扩散的控制。吸附等温线紧密地配合到啜饮等温线模型，并且对合成δ-MnO的铜（II）的理论最大吸附容量₂ / BC级是大约124，154，199，和230毫克/克，在15，25，35和分别为45°C。吸附-解吸研究证明了δ-的MnO的可回收₂用于从水溶液中去除的Cu（II）的/的BC。