A novel biological graphene aerogel (BGA) was fabricated by using bacteria in waste activated sludge (AS) as cross-linker, and ionic dye as surface charge modification reagent. Through rheological measurement and electron microscopy, this AS-BGA was confirmed an elastic porous structure with packing bacteria inside graphene oxide (GO) sheets. A variety of chemical elemental analysis demonstrated that GO was reduced by the bacteria to reduced graphene oxide (rGO) alongside the gelation process. Further, methylene blue (MB), methyl orange (MO) and Congo red (CR) were used to alter GO’s surface charge owing to the electrostatic and π-π stacking effect. Accordingly, the surface electronic properties of the AS-BGA prepared by the functionalized GO exhibited a consistent change, i.e., electronegativity was enhanced by anionic MO and CR, meanwhile neutralized by cationic MB. Thereby, the adsorption capability of the AS-BGA with the optimal functionalization conditions through MO was increased 1.24-fold higher than the unfunctionalized one. Furthermore, the raw material and energy consumptions related to the synthesis of AS-BGA was analyzed by the life cycle assessment method. This study points to the reuse of the excess bacteria and organic compounds to derive adsorbents for sustainable wastewater treatment, by exploiting graphene materials in an exquisite way.

以废活性污泥（AS）中的细菌为交联剂，离子染料为表面电荷改性剂，制备了一种新型的生物石墨烯气凝胶（BGA）。通过流变学测量和电子显微镜观察，确认该AS-BGA为弹性多孔结构，在氧化石墨烯（GO）片材内部填充细菌。各种化学元素分析表明，伴随凝胶化过程，细菌将GO还原为氧化石墨烯（rGO）。此外，由于静电和π-π堆积效应，使用亚甲基蓝（MB），甲基橙（MO）和刚果红（CR）来改变GO的表面电荷。因此，由官能化的GO制备的AS-BGA的表面电子性质呈现出一致的变化，即，阴离子MO和CR增强了电负性，同时被阳离子MB中和。因此，具有最佳官能化条件的AS-BGA通过MO的吸附能力比未官能化的AS-BGA高1.24倍。此外，通过生命周期评估方法分析了与合成AS-BGA有关的原材料和能源消耗。这项研究指出，通过以一种精美的方式利用石墨烯材料，可以将多余的细菌和有机化合物再利用来获得吸附剂，以进行可持续的废水处理。采用生命周期评估方法分析了与合成AS-BGA有关的原材料和能源消耗。这项研究指出，通过以一种精美的方式利用石墨烯材料，可以将多余的细菌和有机化合物再利用来获得吸附剂，以进行可持续的废水处理。采用生命周期评估方法分析了与合成AS-BGA有关的原材料和能源消耗。这项研究指出，通过以一种精美的方式利用石墨烯材料，可以将多余的细菌和有机化合物再利用来获得吸附剂，以进行可持续的废水处理。