The dye and heavy metal are two principal concomitant pollutants in industrial wastewaters, posing a serious threat to public health and the environment. Herein, we developed a novel strategy to convert banana peels into hierarchically porous carbon (BPCA) and porous carbon oxide (BPCAO) for the simultaneous removal of methylene blue (MB) and Co(II). The as-prepared carbons were systematically characterized by SEM, TEM, BET, FT-IR and XPS. Compared to BPCA, BPCAO showed a better adsorption performance due to its abundant surface oxygen-containing groups. In the mono-component systems, both MB and Co(II) adsorption onto BPCAO were well described by the pseudo-second-order and Langmuir models. The maximum adsorption capacities of MB and Co(II) were calculated to be 1303.54 and 122.39 mg/g at 298 K, respectively. In the binary system, the interaction between MB and Co(II) was determined and it depended on the initial concentration of Co(II). The adsorption mechanism of MB involved electrostatic interaction, π-π stacking and hydrogen-bonding while that of Co(II) was mainly ruled by the complexation and/or ion-exchange. This study indicated BPCAO could be a favorable biomass-derived adsorbent for the simultaneous removal of the dye and heavy metal.

染料和重金属是工业废水中的两种主要伴随污染物，对公众健康和环境构成了严重威胁。在这里，我们开发了一种新颖的策略，可以将香蕉皮转化为分级多孔碳（BPCA）和多孔碳氧化物（BPCAO），以同时去除亚甲基蓝（MB）和Co（II）。通过SEM，TEM，BET，FT-IR和XPS对制得的碳进行了系统表征。与BPCA相比，BPCAO由于其丰富的表面含氧基团而具有更好的吸附性能。在单组分系统中，MB和Co（II）在BPCAO上的吸附均通过拟二阶模型和Langmuir模型进行了很好的描述。MB和Co（II）在298 K时的最大吸附容量分别为1303.54和122.39 mg / g。在二进制系统中 测定了MB与Co（II）之间的相互作用，这取决于Co（II）的初始浓度。MB的吸附机理包括静电相互作用，π-π堆积和氢键结合，而Co（II）的吸附机理主要受络合和/或离子交换的影响。这项研究表明，BPCAO可能是一种有利的生物质衍生吸附剂，用于同时去除染料和重金属。