Bamboo-based lignin (LBM) was synthesized from a simulated effluent of modified textile manufacturing process for bamboo fabrics. The efficacy of LBM modified with Al3+ (Al-LBM) and Mn2+ (Mn-LBM) for the remediation of crystal violet dye polluted wastewater was evaluated. Instrumental characterization of the adsorbents via Fourier transform infrared spectroscopy and scanning electron microscopy was conducted. Probable process mechanisms were postulated. The Langmuir, Sip and Freundlich isotherms were the best fit model for LBM, Al-LBM and Mn-LBM, respectively. Among the interactively competing mechanisms (confirmed by k-value and intra-particle diffusion model), the pseudofirst-order kinetic model predominated. Optimum temperature and contact time were 343 K and 30 min, respectively. The adsorption process was (based on average data) spontaneous (∆G = − 1198.69 kJ mol−1), endothermic (ΔH = + 86.85 kJ mol−1) and efficient (+ 98.11%).