Metal pollution 4 article 4 comparative study 4 sorption 4 AS models 2 Absorption 2 Acids 2 Adsorption 2 Adsorption isotherms 2 Alkali Lignins 2 Alloy 2 Atmospheric temperature 2 Biosorbent 2 Biosorption 2 Chemical oxygen demand 2 Chemicals removal (water treatment) 2 Complexation 2 Computer Simulation 2 Demineralisation 2 Demineralised lignin 2 Dilute solutions 2 Equilibrium conditions 2 Equilibrium isotherms 2 Feasibility Studies 2 Humic Substances 2 Hydrogen-Ion Concentration 2 Industrial Wastes 2 Industrial water treatment 2 Infrared spectroscopy 2 Iron Compounds 2