The growing demand for clean water, driven by population growth, urbanization, and industrialization, has intensified the need for effective water purification methods. Contamination by heavy metals, chemical compounds, microplastics, and pharmaceutical waste poses significant risks to ecosystems and human health.Lignin, a natural biopolymer with a high density of functional groups, can effectively bind cations. However, its use in industrial water treatment is limited by the formation of colloidal solutions. This study introduces a lignin-silica biocomposite as an efficient sorbent for removing cationic pollutants from wastewater. A rapid, eco-friendly method was developed to immobilize Kraft lignin on mesoporous silica. The biocomposite was characterized using Diffuse Reflectance (DRS), Fourier Transform Infrared (FTIR) Spectroscopy, and adsorption analysis. It showed high mechanical and chemical stability, did not swell in water, and could be easily separated from the solution.The sorbent exhibited high capacity for removing heavy metal cations, dyes, and cationic pharmaceuticals, with adsorption capacities of 0.98 mmol Cu(II) and 1.21 mmol Cr(III) per gram, three times higher than lignin or silica alone. It effectively removed Cu(II) and Cr(III) ions within 20 minutes.The high adsorption capacity, fast kinetics, and regenerability of the lignin-silica biocomposite make it a promising candidate for large-scale wastewater purification. Using lignin, a byproduct of the pulp and paper industry, promotes an eco-friendly approach to water treatment, supporting circular economy goals and waste reduction.This study highlights the potential of lignin-silica biocomposites as sustainable solutions for global water purification challenges.