Table 1 showed thatchitosanscouldadsorbboththemetalions and themetalhydroxidecolloids.Theadsorptionofmanganese ions fromsolutionisoneorderhigherthanthatfromcolloidsfor 85% DDchitosanandslightlyhigherfor95%DDchitosan,whereas copper ionsweremorereadilyadsorbedafter20minatroomtem- perature thancopperhydroxidecolloidswere.Comparedtoiron and manganese,thechitosansadsorbedmuchlessmanganeseions and thecorrespondingmetalcolloids.Themetalcolloidofironwas almost completelyadsorbedbythechitosansattwoadsorption conditions, buttheadsorbedmetalcolloidsofcopperandman- ganese bychitosanswerehigherafteradsorbed20minatroom temperature followedby120minat80 ◦C thanthatofadsorbed 20 minatroomtemperature.ThechitosanwithaDDof95%could adsorb moremetalsthanthechitosanwithaDDof85%could.For chitosans, theabilityofadsorptionofmetalsrelatedtothefree amino-group (NH2) inchitosans(Burke etal.,2000;Parketal., 2004; Xueetal.,1998). ThechitosanwithahigherDDhasmore free amino-group,soitcanadsorbedmoremetals.