Waste natural materials (WNM) were converted into anion-exchangers through consecutive chemical reactions with thionylchloride, N,N-Dimethylformamide (DMF), dimethylamine and formaldehyde as crosslinking agents. The final products obtained were weak-base anion-exchangers with tertiary amines as major functional exchange groups. WNM containing small amounts of extractives gave higher yields. Also, anion-exchangers produced from WNM with higher lignin content gave higher maximum nitrate adsorption capacity (Q(max)). Moringa oleifera (M. oleifera) hull with the highest lignin content of 30.4% showed the highest Q(max) of 0.20 mmol NO3- per g of resin, followed by coconut husk, sawdust of lauan and rice hull. Anion-exchangers produced from WNM and mixtures of pure lignin and pure cellulose demonstrated that lignin is the major reactive component responsible for the anion-exchanger and cellulose seems to be a supporting material for the exchangers. (C) 2003 Elsevier Science B.V. All rights reserved.