| 摘要 |
<p>. An anion exchanger is produced by treating cellulose or a cellulose derivative with a polyethylene imine solution of at least 1% by weight in an aqueous medium at a pH-value between 2 and 6, preferably between 4 and 5, and recovering the ion exchanger from the reaction mixture. The reaction between cellulose or cellulose derivative and polyethylene imine can take place at ambient temperature, but may be promoted by using a temperature of 40-90.degree. C, preferably 60-70.degree.C. Preferred cellulose derivatives for use as starting material are sulphonated lignocellulose or a cellulose material, e.g. bark which has been treated in separate steps with an alkali hydroxide solution and with sulphuric acid. The anion exchanger can be regenerated by el?tion with sodium hydroxide and reactivated by treatment with polyethylene imine. The anion exchanger is suitable for the purification of waste water and can be produced at low cost.</p> |
