Acrylic composite resin modified by calcium lignosulphonate (LSAA) was prepared by solution polymerization using calcium lignosulphonate (LS-Ca) and acrylic acid (AA) as raw materials

and ethylene glycol dimethacrylate (EGDMA) as the cross-linker.LSAA was characterised using Fourier transform infrared spectroscopy (FTIR)

scanning electron microscopy (SEM)

thermogravimetric analysis (TG) and specific surface analysis.TG result showed that the initial temperature of decomposition was 291.2 ℃ and LSAA was good in thermal stability.LSAA had good adsorption capability to methyl orange (MO) because of the rough surface and abundant mesoporous

as well as the hydroxyl groups on the surface of LSAA.The optimum pH was 3.0 and LSAA had adsorption capacity of 188.33 mgg-1 after 24 h at 298 K.The adsorption of MO on LSAA was an exothermic typical physical adsorption process which was in accordance with both Langmuir and Freundlich isotherm equations.The kinetic study indicated that adsorption followed the pseudo second-order model.Kannan-Sundaram model showed that the adsorption process of MO on LSAA was divided into three stages

the surface adsorption of adsorbent

the slow diffusion of the hole and the slow diffusion of the small hole

and these lines did not pass through the origin

which meant inner diffusion of the particles was not the sole controlling step of adsorption process.