Heavy metal contamination has prevented the sustainable and efficient utilization of wastewater. Biosorption is a promising process which means technical innovation and biomaterials preparation to remove pollutants from water solutions. In this study, a novel lignosulfonate-modified graphene hydrogel (LGH) was successfully prepared to remove Cr(VI) from aqueous solution. Results indicated the combination of lignosulfonate and graphene could significantly improve the adsorption performance of LGH. The obtained biomaterials LGH were characterized by FT-IR, XPS, BET, TGA, and SEM. Results showed that LGH has a high specific surface area, interconnected porous structure, and plenty of oxygen-containing groups, which are particularly suitable to adsorb heavy metals. Experimental results indicated an ultrahigh adsorption capacity of 1743.9 mg/g for Cr(VI) capture, and has been found to be the highest among the previously reported values on Cr(VI) adsorption by various lignin/lignosulfonate-based adsorbents. Systematic kinetic and isotherm studies were performed to investigate the adsorption behaviors of Cr(VI) by LGH. Results showed that the adsorption of Cr(VI) by LGH follows the pseudo-second-order model and the equilibrium data consistent with Langmuir isotherm model. The active groups presented in LGH were related to the binding of Cr(VI), and electrostatic adsorption and chemisorption could be the major adsorption mechanisms. The recycling and reuse of LGH was successfully achieved by using 0.1 M NaOH without destroying its original hydrogel structure, and more than 88% reuse efficiency of Cr(VI) (300 mg/L) was obtained after 5 cycles. The results suggest a promising approach by utilizing low-cost lignosulfonate for the high-potential purification and sustainable utilization of wastewater, especially for the high concentrations of heavy metal polluted wastewater treatment.

重金属污染阻碍了废水的可持续和有效利用。生物吸附是一个有前途的过程，这意味着技术创新和生物材料的制备，以去除水溶液中的污染物。在这项研究中，成功​​制备了一种新型的木质素磺酸盐修饰的石墨烯水凝胶（LGH），用于从水溶液中去除Cr（VI）。结果表明，木质素磺酸盐和石墨烯的组合可以显着提高LGH的吸附性能。通过FT-IR，XPS，BET，TGA和SEM对获得的生物材料LGH进行表征。结果表明，LGH具有较高的比表面积，相互连接的多孔结构和大量的含氧基团，特别适合吸附重金属。实验结果表明，其超高吸附容量为1743。Cr（VI）的捕获量为9 mg / g，在先前报道的各种木质素/木质素磺酸盐基吸附剂对Cr（VI）的吸附值中，这是最高的。进行了系统动力学和等温线研究，以研究LGH对Cr（VI）的吸附行为。结果表明，LGH对Cr（VI）的吸附遵循伪二级模型，平衡数据与Langmuir等温线模型一致。LGH中存在的活性基团与Cr（VI）的结合有关，静电吸附和化学吸附可能是主要的吸附机理。通过使用0.1 M NaOH而不破坏其原始水凝胶结构，成功实现了LGH的回收和再利用，经过5个循环后，Cr（VI）（300 mg / L）的再利用效率达到88％以上。