In this study, a redox precipitation method was used to load manganese dioxide (MnO₂) nanoparticles on biochar (BC) (BC@MnO₂) pyrolyzed from the invasive water hyacinth, and the adsorption of Cd(II),Cu(II), Zn(II), and Pb(II) was investigated. Several techniques were used to characterize the adsorbents. The results revealed that the BC surface was covered by many intertwined thin amorphous MnO₂ nanosheets, which significantly increased its specific surface area and pore volume. The adsorption of heavy metal ions by BC was negligible, whereas the MnO₂-containing adsorbents exhibited a high capacity for adsorbing heavy metal ions. However, the MnO₂-normalized adsorption amount decreased with increasing MnO₂ load and was largely unchanged at MnO₂ loads of 26.6% to 30.2%. The capacity for adsorbing heavy metal ions of BC@MnO₂ was pH-dependent, but the adsorption affinity was unaffected by coexisting ions. Column tests revealed that BC@MnO₂ with a load of 26.6% had a high capacity for removing heavy metal ions from simulated and real electroplating wastewater. Therefore, BC@MnO₂ with a load of 26.6% shows promise as a regenerable adsorbent for removing heavy metal ions from water/wastewater. This study could lay an essential foundation to develop a win-win strategy for heavy metal ions removal from wastewater using biochar derived from water hyacinth.

在这项研究中，氧化还原沉淀法被用于将二氧化锰（MnO ₂）纳米颗粒负载在由侵入性水葫芦热解的生物炭（BC）（BC @ MnO ₂）上，并吸附Cd（II），Cu（II） ，Zn（II）和Pb（II）。使用了几种技术来表征吸附剂。结果表明，BC表面被许多相互缠绕的非晶态MnO ₂薄纳米片覆盖，这大大增加了其比表面积和孔体积。BC对重金属离子的吸附可以忽略不计，而含MnO ₂的吸附剂表现出高的重金属离子吸附能力。但是，MnO ₂归一化吸附量随MnO的增加而降低₂负载，在MnO ₂负载为26.6％至30.2％时基本保持不变。BC @ MnO _2的重金属离子的吸附能力是pH依赖性的，但吸附亲和力不受共存离子的影响。柱测试表明，负载率为26.6％的BC @ MnO ₂具有很高的去除模拟和真实电镀废水中重金属离子的能力。因此，负载为26.6％的BC @ MnO ₂有望作为一种可再生的吸附剂从水中去除废水中的重金属离子。这项研究可为开发一种双赢的策略奠定重要基础，该策略将使用风信子中的生物炭去除废水中的重金属离子。