음이온성과 양이온성 셀룰로오스 나노섬유를 이용한 수처리용 멤브레인 필터 개발

Abstract

This study examined the effect of cellulose nanofiber (CNF) type on the performance of ion absorbing membrane filters made of anionic and cationic CNFs. Four types of anionic and cationic CNFs were made by beating, micro-grinding, carboxymethylation and quaterniza- tion using hardwood bleached kraft pulp (Hw-BKP): refining-CNF (RE-CNF), car- boxymethylated CNF (CM-CNF), surface-modified CNF with cationic poly-DADMAC (pD- CNF), and quaternized CNF (Q-CNF). The membrane filters were composed of two-layers: One layer was made of anionic CNF and poly-aminiamide-epi-chlorohydrin (PAE) and the other layer was made of cationic CNF. The membrane filter was produced by vacuum fil- tration and the use of two CNF slurries. In addition, the capacity to remove Fe and Cl ions from the water was analyzed by carrying out high-pressure filtration experiments with a 500 ppm concentration of the Fe and Cl standard solutions respectively, using the same methods as the previous study. Four types of CNFs were sufficiently fibrillated at the nano-level and had electrostatically intended zeta-potential. The CM-CNF, which had a strong negative zeta-potential, was effective in the adsorption of Fe ions, and the Q-CNF, which was strong in cationic prop- erty, was effective in the adsorption of Cl ions. Therefore, it was concluded that cationic Q-CNF and anionic CM-CNF could be effectively utilized for the manufacture of a mem- brane filter to remove metal and anionic ions from water simultaneously.