Cellulose beads loaded with graphene nanoplatelets (GNP) were prepared by a physical gelation method, which was feasible under mild conditions. The phases spontaneously separate when the cellulosic solution is dropped into an acid solution, maintaining semi-spherical shapes with diameter between 3.4 and 3.9 mm, which is desirable for continuous-flow systems. Beads were tested for the removal of Congo red dye using a differential column batch reactor. Langmuir isotherm described the adsorption equilibrium, with maximum adsorption capacities of 98.1 and 139.6 mg/g for cellulose and cellulose-GNP beads. GNP increased the number of binding sites in the adsorbent. Removal efficiencies were higher than 90% within a broad range of initial concentration and sorbent loading. Static batch experiments evidenced slow kinetics for both sorbents, reaching equilibrium after 400 min. Hence, mass transfer was enhanced using a differential column batch reactor. The mass transfer coefficient, k_L increased from 3.16 × 10⁻⁴ to 6.94 × 10⁻⁴ L/mg min, reaching equilibrium in half of the static adsorption time. External mass transfer resistance was minimized as turbulent flow is developed around the sorbent particles, allowing to obtain adsorption efficiencies close to 100% in a reasonably low time of 100 min. GNP promoted faster kinetics, as k_L was 7.58 × 10⁻⁴ L/mg min. A model was developed to describe the adsorption dynamics based on the equilibrium. Although desorption was not favorable, cellulose-GNP beads’ direct disposal is attractive due to the sorbent’s hydrogel-like nature. A future work perspective is to evaluate these adsorbents under continuous fixed-bed operation.

通过物理凝胶法制备了负载石墨烯纳米片（GNP）的纤维素珠，这在温和的条件下是可行的。当将纤维素溶液滴入酸性溶液时，各相自发分离，从而保持直径在3.4到3.9 mm之间的半球形，这对于连续流系统是理想的。使用差分柱间歇式反应器测试珠粒对刚果红染料的去除。Langmuir等温线描述了吸附平衡，纤维素和纤维素-GNP珠的最大吸附容量为98.1和139.6 mg / g。GNP增加了吸附剂中结合位点的数量。在广泛的初始浓度和吸附剂载量范围内，去除效率均高于90％。静态批处理实验证明两种吸附剂的动力学很慢，400分钟后达到平衡。因此，使用差分塔间歇式反应器提高了传质。传质系数k _L从3.16×10 ^-4增加到6.94×10 ^-4 L / mg min，在一半的静态吸附时间达到平衡。由于在吸附剂颗粒周围形成湍流，使外部传质阻力减至最小，从而在合理的100分钟内即可获得接近100％的吸附效率。GNP促进了更快的动力学，因为k _L为7.58×10 ^-4 L / mg min。开发了一个模型来描述基于平衡的吸附动力学。尽管解吸不利，但是由于吸附剂具有类似水凝胶的性质，所以纤维素-GNP珠的直接处理很有吸引力。未来的工作前景是在连续固定床操作下评估这些吸附剂。